[HN Gopher] Starship Flight 5: Launch and booster catch [video]
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Starship Flight 5: Launch and booster catch [video]
Author : alecco
Score : 2185 points
Date : 2024-10-13 12:23 UTC (1 days ago)
(HTM) web link (twitter.com)
(TXT) w3m dump (twitter.com)
| DarmokJalad1701 wrote:
| They caught it! Holy sh*t!
| dotnet00 wrote:
| All the renders in the world couldn't have prepared me for how
| crazy the actual catch looked!
| choonway wrote:
| ok now they have an actual reference and can animate it better
| haha.
| helpfulContrib wrote:
| Amazing days ahead of us - if we can avoid blowing ourselves up
| over pathetic patches of land, we could have the entire solar
| system under our feet...
| falcor84 wrote:
| Agreed, but I'm concerned that humans being humans, we'll have
| the entire solar system to blow ourselves over.
|
| In The Expanse (which I highly recommend), they give a new
| lease on life to that quote attributed to Einstein "I know not
| with what weapons World War III will be fought with, but World
| War IV will be fought with sticks and stones" - hurling
| asteroids towards a planet. I really hope humanity's real
| future will play out in accordance with some of the more
| optimistic elements in The Expanse.
| the_gorilla wrote:
| > pathetic patches of land
|
| It's always funny seeing people pretend they live in a world
| where small issues like land or food don't affect them, even
| though they only have that privilege because a larger military
| says they should.
| nycdotnet wrote:
| They did it!
| jmyeet wrote:
| Stage 1 sucessfully caught. That was pretty incredible. I
| remember watching the Falcony Heavy launch when both boosters
| landed in sync.
|
| It's hanging pretty high in the air, I assume so the engines do
| less damage to the pad. One wonders how they're going to get it
| down. Do the chopsticks lower on the tower?
| chinathrow wrote:
| Yes, the chopsticks are attached to one giant lift.
| stagezerowil wrote:
| Yes, the chopsticks lower and raise. They will lower the tower
| onto a transport vehicle and send it back to the bay for
| examination, and then possible reflight.
| dotnet00 wrote:
| Yep, they handle all the mounting/demounting ops on the launch
| mount, so they have to be able to move along the tower.
| sbuttgereit wrote:
| They'll lower it to the launch mount... the catch arms are
| effectively a crane. But I wonder if it's more "toasty" than
| they were expecting? There were some fires going at catch
| (those look out, at least on external camera views) and the
| engines are still a bit.... smokey. Don't know if that's
| normal... or if they were expecting it.
|
| My hunch is that they don't put it down for awhile. If there's
| still an issue were there are fires lingering inside, my hunch
| is they want that as far from the ground infrastructure as
| possible.
|
| Either way incredible progress.
| minetest2048 wrote:
| From the replay, it seems that the fire comes from methane
| from the RCS thrusters burning, so it seems normal
| sbuttgereit wrote:
| The fire I mostly saw was coming from the quick disconnect
| ports and related plumbing. Also, there was fire on the
| other side, close to where there was part of a chine was
| clearly missing. There were a couple other things, too.
|
| Wasn't perfect, some things to work out... but still pretty
| damn good.
| chasd00 wrote:
| Remember on the first launch when, on the way up, there
| were hydraulic units exploding off the side and the
| engines started exploding taking out more hydraulic
| units? Heh that and all the concrete flying up on
| ignition was like watching a heavy metal music video.
| chasd00 wrote:
| There was a lot of smoke coming out of the bottom after the
| catch. I was worried about an internal fire but it's since
| stopped. The glow from the engine mount on re-entry was
| amazing. The fire on landing had me worried too I was
| expecting it to grow but put itself out eventually.
|
| What an amazing morning!
| BOOSTERHIDROGEN wrote:
| Congratulations.
| valenceelectron wrote:
| Although this is by far not the first landing of SpaceX boosters
| I've seen, this looked like scifi to me even in 2024.
| stagezerowil wrote:
| Holy hell, they caught the booster!
| ipnon wrote:
| Moon by 2030 and Mars by 2040 seems like a winning bet lately
| TrapLord_Rhodo wrote:
| The Delta-V is comparable since you can aerobrake on mars. It's
| only the difference between the time.
|
| Earth to moon without Aerobraking is a delta v of around 13k/s,
| mars is 13.3
| napsterbr wrote:
| And here I thought nothing would top the double landing view from
| Falcon Heavy...
| NoxiousPluK wrote:
| That was such a magical moment
| treespace8 wrote:
| I'm just so happy to see this level of progress. This another big
| step for opening up space. To think that one day this will be
| considered normal. 150 Metric tons sent on a fully reusable
| rocket.
|
| Thats like a 747 to space.
| Waterluvian wrote:
| Is that 150t of payload or total? What's the cost in fuel alone
| (let's ignore maintenance and operations costs for now)? I'm
| trying to get a feel for the relative scale compared to today's
| commercial flight.
| treespace8 wrote:
| It was just a quick google. 150t reusable.
|
| No idea about the other costs.
| dotnet00 wrote:
| They previously threw around a number of around $1M per
| flight, as mostly fuel costs.
|
| Also, while 150t is the target payload capacity, the current
| test vehicles are closer to 50t in payload capacity, there
| are revisions in the pipeline based on data from these test
| flights which will bring it up to 150t.
| pfdietz wrote:
| To put this in perspective: at 150t/launch, if a launch is
| $1M, then for the cost of an SLS launch (at least $2B)
| Starship could launch 300,000 tons, about the mass of three
| Nimitz-class nuclear aircraft carriers.
| Waterluvian wrote:
| We could use a few of those in orbit.
| mensetmanusman wrote:
| America funding the literal eye of Sauron 2.0
| pclmulqdq wrote:
| None of the vehicles have demonstrated any payload capacity
| yet. 50 tons is the on-paper capacity only, and seems quite
| high given how little fuel is left when the bring an empty
| starship to orbital altitude. I assume that as the engines
| and launch procedures get more efficient, they will start
| being able to bring stuff to orbit (and quite a bit of
| stuff, too).
| cjbillington wrote:
| They've actually been having to dump propellant in order
| to more accurately test what a Starship in orbit would be
| like, given they're not flying with a payload that would
| consume that propellant on ascent, but that they still
| want to launch with a full tank.
|
| The dumping of this excess propellant actually caused an
| explosion and loss of vehicle on the second test flight.
| pclmulqdq wrote:
| That's what they said about the second test flight (and
| the third), but the webcast recordings looked a lot more
| like fuel leaks to me, and that is in line with Starship
| and early Falcon's past issues. I'm going to press X to
| doubt that the dumping narrative is the truth, since a
| nice face-saving white lie is in every corporation's
| handbook.
| jillesvangurp wrote:
| Methane is about 900-1500$ / ton. About 1000 tons is used for
| the launch in addition to 3600 tons of lox. That should be a
| bit cheaper than methane per ton. Ballpark, the propellant
| might cost around 2M$.
|
| A modern airliner on a long flight might burn around 80 tons
| of kerosene. It's slightly cheaper than methane. Call it
| 75-80K$.
| bombcar wrote:
| That's $7 of fuel per pound of payload, that is _not bad_
| at all.
| pfdietz wrote:
| Indeed. You sometime see an argument that launch to space
| is expensive because of the propellant and therefore
| energy required. And as you note this argument is utterly
| wrong.
| throwaway4aday wrote:
| not sure how anyone can miss the "throwing away the
| airplane" part as being the cost driver.
| pfdietz wrote:
| It's the same cognitive error as thinking nuclear energy
| must be cheap because the fuel is cheap.
| TMWNN wrote:
| >And as you note this argument is utterly wrong.
|
| Am I mistaken, or are there distance/payload combinations
| for which Starship is cheaper per pound on a point-to-
| point basis than air transport, even setting aside 30
| minutes versus 12 hours? Isn't that the non-intuitive
| outcome of ballistic trajectories?
| adastra22 wrote:
| No. But it gets within an order of magnitude, which is
| remarkable. Economy class on starship could be priced
| similar to first class tickets on transoceanic flights.
| zaroth wrote:
| Is the $1000/ton a law a physics, or could that ever
| possibly scale up and come down an order of magnitude?
| pfdietz wrote:
| There are no dollars in the laws of physics. It's
| connected ultimately to productivity of all the
| activities involved, and there's no obvious upper bound
| to productivity.
| WalterBright wrote:
| There's the rocket equation.
|
| https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation
| pfdietz wrote:
| Which doesn't have dollars anywhere in it.
| WalterBright wrote:
| The point of the rocket equation is there are hard
| physical limits on what rockets can do, and dollars won't
| change it.
| pfdietz wrote:
| That's nice. It doesn't imply a lower bound for costs,
| just of ratios of costs.
| jillesvangurp wrote:
| Just the current market price for fossil methane, which
| of course goes up and down. But I'm assuming SpaceX gets
| their methane on the open market.
|
| It's quite possible that SpaceX has access to some
| cheaper methane source. Texas produces a lot of it.
|
| And SpaceX has speculated about eventually switching to
| some renewable source by e.g. synthesizing methane. In
| which case that would boil down to cost of electricity
| and carbon. I don't see that becoming cheaper short term
| but that could happen long term.
| flaburgan wrote:
| So, reusable is supposed to reduce the cost. But the space
| shuttle was reusable and it has been shutdown because it was
| too expensive. What is the differences between the two?
| kortilla wrote:
| SRB and tank were not re-usable. That's the equivalent of the
| first stage you just saw getting caught
| throwaway48476 wrote:
| Shuttle SRB segments were fished from the ocean and
| refilled.
| baq wrote:
| Yeah but salt water makes it about as difficult as
| building from scratch.
| throwaway48476 wrote:
| Then why didn't they stop?
| JumpCrisscross wrote:
| > _why didn 't they stop?_
|
| They did [1].
|
| [1]
| https://en.m.wikipedia.org/wiki/Space_Shuttle_retirement
| altcognito wrote:
| Beyond the fact that they eventually did quit, the
| shuttle program was the public face of the US space
| program, and part of having more than one way to launch
| military stuff.
| pfdietz wrote:
| The military rapidly gave up on the Shuttle after the
| first accident. No shuttle was ever launched from the pad
| on the west coast at Vandenberg (plenty of F9s have been,
| though.)
| adt2bt wrote:
| SRBs were in fact reusable.
| ericcumbee wrote:
| They were but the cost of refurbishment was almost more
| than just building new boosters. Thats why SLS is
| currently using Shuttle Derived Boosters but not worrying
| with reuse.
| YoumuChan wrote:
| Economy of scale: starship can be "mass"-produced
|
| Material: stainless steel is much cheaper
|
| Percentage of reusability: boosters of shuttle cannot be
| reused, maintenance of shuttle itself is also very expensive
| (heat shields were pricey). whereas the starship stack has
| higher reuse percentage and allegedly cheaper to maintain.
| moffkalast wrote:
| The shuttle was not even reusable by any modern metric, the
| main tank was always expended, the boosters had to be
| recovered, fully disassembled and cleaned.
| pfdietz wrote:
| I'm not even sure the SRM case segments could be easily
| reused, given the tremendous stress. They were made of a
| very high strength steel (maraging steel, with a yield
| stress of something like 250,000 psi) operated with a
| safety factor of 1.4.
| noitpmeder wrote:
| This is significantly less expensive
| fragmede wrote:
| the space shuttle was "reusable". It had to be taken apart
| and meticulously cleaned and tested and basically had to be
| rebuilt after each flight, in a process called turnaround.
| SpaceX's rockets are much closer to what you'd consider
| reusable.
| usrusr wrote:
| I wonder how much of that difference is because the space
| shuttle was human rated from the start: F9 eventually got
| there, but only after plenty of "testing in production"
| with disposable payloads.
|
| The other big difference, an elephant in the room grade
| difference I think, is that SpaceX reliability was
| developed with memories of a reusable vehicle failing
| mostly due to turnaround costs and risks on everyone's
| minds. That clearly wasn't the case when the space shuttle
| was designed, they were the first and enjoyed the privilege
| of making all the beginner mistakes.
| WalterBright wrote:
| I had an email exchange with Homer Hickam, before SpaceX
| existed, where I remarked that the shuttle design looked
| like a giant kludge, and a winged reentry vehicle was a
| fundamentally bad design, for various reasons which I
| enumerated elsewhere in this thread.
|
| He emailed back that he agreed with my reasons and had
| argued that case with NASA in the early stages of the
| shuttle program.
|
| So NASA was aware of this at the time.
| mhh__ wrote:
| I was under the impression tha they also thought this
| themselves but got "persuaded" with the prospect of more
| money if it could handle certain payloads of use for
| defense?
| baq wrote:
| Shuttle was a jobs program just like the SLS is.
| pfdietz wrote:
| The case for the Shuttle was so marginal they needed
| every prospective customer they could get. The military
| was dragged into it unwillingly, but did give their
| requirements when forced to commit. They backed out as
| quickly as possible after the Challenger disaster.
| moffkalast wrote:
| Yeah the right word is refurbishable, plus the main tank
| was not reused and the solid boosters got a salt water bath
| each launch.
| adt2bt wrote:
| Think of the word 'reusable' in this case as less a binary
| descriptor but more of a scale of reusability.
|
| Yes, both systems are reusable, but there are key differences
| in the refurbishment of the systems that partly explains the
| cost difference. It took more labor, resources and time to
| refurbish the shuttle. Also consider rapid reusability was a
| stretch goal when it was being designed, but we have come a
| loooong way since, spacex in particular has had it as a
| driving competitive differentiator for years now.
|
| Another big difference is that NASA post Cold War was a
| skilled jobs program, with an incentive to do distributed,
| high overhead work to appease their bosses (congress), while
| SpaceX has the opposite.
| cubefox wrote:
| > Yes, both systems are reusable, but there are key
| differences in the refurbishment of the systems that partly
| explains the cost difference. It took more labor, resources
| and time to refurbish the shuttle.
|
| Starship uses essentially the same ceramic heat shield
| tiles as the Space Shuttle, so the fact the Shuttle had so
| much trouble with refurbishment doesn't mean that SpaceX
| has solved these refurbishment issues with the Starship
| upper stage.
|
| Though the Starship lower stage, which contains the most
| expensive engines, doesn't have this problem. Since it
| doesn't need a heat shield. So partial reusability should
| be pretty realistic.
| timschmidt wrote:
| Shuttle's tiles were each unique. Starship is mostly clad
| with identical hexagonal tiles which can be mass produced
| and eventually refurbished by machine. A robot already
| welds on the tile fittings.
| BurningFrog wrote:
| That was 24,300 unique parts rather than 1!
| cubefox wrote:
| Now that's an exaggeration
| BurningFrog wrote:
| More of an ignorant assumption. I asked ChatGPT now, and
| got this:
|
| > In terms of shapes, the tiles were not uniform. In
| fact, there were over 17,000 different shapes used to fit
| specific areas of the shuttle's body. Each tile had to be
| individually manufactured and shaped to fit a precise
| location due to the complex curvature of the shuttle's
| surface. The unique shapes were necessary to ensure that
| every part of the shuttle received the proper protection
| against the extreme temperatures during re-entry.
| cubefox wrote:
| Please don't cite LLMs for factual questions. They are
| prone to confabulation. Why not type the question "How
| many heat shield tiles did the Space Shuttle use?" into
| Google?
|
| https://www.google.com/search?client=firefox-b&sca_esv=11
| e08...
|
| This gives a direct answer (24,300) while citing a NASA
| source.
| BurningFrog wrote:
| Since I mentioned I got the info from ChatGPT, people can
| decide for themselves how much they trust it.
|
| Note that the question here is how many _uniquely shaped_
| tiles there was, not the total number.
|
| This is interesting because if you have to manufacture
| and keep in stock 17,000 separate tile shapes, that will
| be vastly more expensive than SpaceX who, from what I
| hear, only uses a singe hex shaped tile everywhere.
| azernik wrote:
| The tiles are very similar; the attachment system is very
| different (a big part of why Shuttle's were a pain to
| maintain) and Starship's simple shape means most of the
| tiles are the same (the ridiculous number of SKUs was
| another factor in Shuttle TPS costs).
| credit_guy wrote:
| The main difference is that this is built by a private
| corporation who can't afford to throw money away, while the
| Space Shuttle was build by the government, and moreover it
| had to fulfill a number of conflicting requirements, and
| commercial profit was not one of them.
|
| But on a more technical level. I think the vertical landing
| is the main difference. Vertical landing was obviously known
| and done by NASA, this is how the lunar modules landed on the
| Moon. But doing it on Earth, with vehicles weighing hundreds
| of times more, I don't think the world had that technical
| readiness a few decades ago, when the space shuttle was
| designed.
|
| And another major difference is the mass manufacturing idea.
| From the start SpaceX planned for getting to mass manufacture
| its rockets. The Falcon rockets are much cheaper than any
| other alternatives even if you remove the reusability.
|
| Then it's the methane burning engines. This was pure old
| fashioned engineering progress. SpaceX's engines are miracles
| of rocket engineering. Aside from that, the fuel choice is
| extremely smart. Methane is better than all other fuels,
| except for hydrogen. Hydrogen was the fuel of the space
| shuttle, but it's very tricky to work with. It has very low
| volumetric density, so the tank of the space shuttle was
| absolutely humongous. Hydrogen needs to be stored at an
| absurdly low cryogenic temperature, so this adds to the
| complexity. And that tank was not reusable, so it adds to the
| cost.
| haspok wrote:
| Spacex might be a private company, but this project is
| funded by NASA, meaning the American taxpayer. Approved by
| a person whose last act was this approval before leaving
| NASA and joining Spacex (effectively putting money in their
| own pocket).
|
| It is also yet to be seen how Starship will ever be
| profitable (outside of spending government money), who is
| going to pay for those launches and for what purpose. Other
| than Starlink, of course.
| throwaway48476 wrote:
| The problem is that launch costs went down fast but
| satellite costs haven't gone down as fast and still have
| long development timelines. The other problem is the
| market for satellite services hasn't developed as fast as
| anticipated, except for starlink.
| baq wrote:
| Starlink for all intents and purposes is the market for
| satellites now. All the other launches are nice to have
| extras.
|
| Now personally I'm looking forward to NASA, ESA and JAXA
| to launch outer solar system probes like new horizons but
| with tons of fuel left in the tank to safely make orbit
| around there.
| XorNot wrote:
| Having enough lift capacity to take a shot at putting a
| pair of telescopes out far enough to exploit solar
| gravitational lensing to resolve exo-planet surfaces
| would be a hell of a thing. Orbital refueling would mean
| we could reasonably build something big enough to be able
| to boost out that far (would still take decades to
| arrive).
| cryptonector wrote:
| Isn't that 500 AU out?
| XorNot wrote:
| Yes, but the trick with getting there is building the
| vehicle. Time takes care of the rest (you'd do it using
| ion thrusters).
| oceanplexian wrote:
| Starlink is predicted to have something like 6.6B in
| revenue. SpaceX isn't a rocket company they are an ISP
| that launches rockets.
| varjag wrote:
| Is that long term or this year? Because honestly 6.6B is
| not a lot for their scale of operations.
| cdash wrote:
| That is projections for this year only with a target
| closer to 10 billion revenue next year.
| adastra22 wrote:
| SpaceX is profitable from that income alone, even
| allowing for starship development costs.
| mhandley wrote:
| Things can only be cheap if you mass produce them. That
| tends to require standardization of components, and
| inevitably standardized components are a compromise
| between requirements, where up until now, saving mass was
| a critical requirement. If you don't have to care nearly
| so much about mass and volume, then that opens up many
| avenues for much cheaper standard satellite components.
| tuatoru wrote:
| I'm disappointed that you _still_ can 't order ten
| cubesats from Shenzen Satellite Supply Co via AliExpress.
| ufmace wrote:
| The whole design process for them is based around
| launches being expensive and taking a long time to plan.
| It will be very interesting to see what happens when the
| whole process gets used to launches being relatively
| cheap and frequent. No need to spend years making sure
| the design is perfect and will definitely last a long
| time if you can launch a new one in a week if you make a
| mistake.
| Denvercoder9 wrote:
| > this project is funded by NASA
|
| Partially. They have a fixed-price contract to land
| humans on the Moon, and notably got that contract because
| they severely undercut the other bids and were the only
| bid that actually fit within the available budget: they
| bid $2.94B, while Blue Origin bid $5.99B and Dynetics
| $9.08B.
|
| That 3 billion is also much less than what they're
| spending on the project.
| zitterbewegung wrote:
| The purpose of funding SpaceX with taxpayer money is to
| make competitors that can launch rockets to space so that
| it is cheaper.
| mempko wrote:
| Exactly. Private companies like space X would not exist
| if NASA didn't deliberately make the market for Private
| space companies. That's what governments do, make
| markets.
| cryptonector wrote:
| Elon founded SpaceX w/o an expectation of subsidies.
| mmustapic wrote:
| And yet, without the funding for CRS from NASA Spacex
| would've gone broke or at least wouldn have built F9 much
| much later.
| ben_w wrote:
| > Spacex might be a private company, but this project is
| funded by NASA, meaning the American taxpayer.
|
| So was the space shuttle, so that's not _a difference_
| between the launch costs of the two vehicles.
| throwaway4aday wrote:
| With a payload volume of 8m diameter by 22m height you
| could fit a James Webb size telescope inside with minimal
| folding. The sunshield (21.2 m by 14.2m) would only need
| to fold along one axis and the mirror (6.6 m) could be
| monolithic instead of having to fold, probably only
| requiring the mounting points for the primary and
| secondary to be hinged. This shouldn't be discounted
| because it makes telescope design much simpler and less
| expensive.
|
| It also allows for launching individual space station
| modules that have almost the same volume as the entire
| ISS in one launch.
|
| Their plans for refuelling on orbit with tanker versions
| of the starship open up the entire solar system to
| unmanned missions with much shorter timelines and much
| higher payload size and weight.
|
| The fact the entire system is re-usable will make it both
| cheaper and faster to use than any other launch system.
|
| All of this combined mean that it won't just be countries
| and space programs bidding for space on launches, it puts
| space within reach of many corporations and some private
| individuals. This isn't conjecture, it's already
| happening with the Falcon 9. Starship will make it even
| more accessible.
| foobarian wrote:
| > With a payload volume of 8m diameter by 22m height you
| could fit a James Webb size telescope inside with minimal
| folding.
|
| Of course, that means you could also fit a James Webb-
| folded telescope except make it a lot bigger :-)
| throwaway4aday wrote:
| Yes! that too.
| Earw0rm wrote:
| Probably need on-orbit refueling to work for that to
| happen, but they're working on it.
| jvm___ wrote:
| Just park the starship as the sun shield. Or two
| starship, or an origami starship that unfolds for more
| surface area, your own personal sun umbrella made from a
| starship.
| throw4950sh06 wrote:
| > It also allows for launching individual space station
| modules that have almost the same volume as the entire
| ISS in one launch.
|
| My favorite related thing is that the Starship itself
| could serve as a large space or moon station.
| bryanlarsen wrote:
| > but this project is funded by NASA
|
| About 10% funded by NASA. Starship is a >$10B program;
| SpaceX is getting $3B for Artemis of which >2/3 is for
| operational tasks and moon-specific stuff that SpaceX
| aren't relevant for SpaceX's goals of LEO and Mars.
| cryptonector wrote:
| The Artemis money could evaporate and Starship would
| still make commercial sense and likely be a successful
| product.
| mensetmanusman wrote:
| The federal government smartly invested in SpaceX after
| being sued by SpaceX to fix rigging (things what the
| system working looks like).
|
| Now taxpayers have a 10x return on investment.
| WalterBright wrote:
| > and commercial profit was not one of them
|
| But it's high cost was the end of it.
| cryptonector wrote:
| Its high cost would (should!) have killed it regardless,
| but its low reliability was going to be a huge problem
| too, and arguably it's the lack of reliability that
| finally killed it.
|
| The high cost should have killed the project before it
| ever flew, but that's not how governments behave.
| WalterBright wrote:
| In order to land as a glider, you'll need wings, landing
| gear, doors, rudder, stabilizer, flight controls,
| streamlining, all the structure needed to support it, and a
| heat shield for all of it. All that complexity has to work
| reliably, too.
|
| All of that adds tremendous weight, complexity, and cost.
| bamboozled wrote:
| What is all this rocketry doing for climate change if
| they're burning methane? Hopefully it's methane from
| landfills etc?
| credit_guy wrote:
| I did the math, and the impact is not negligible. One
| single launch releases the equivalent of 5000 tons of
| CO2. Elon wants to get to the point where there are
| thousands of Starships, each doing a few trips to orbits
| _per day_. That would be more than one millions launches
| per year, or more than 5 GT of CO2-equivalent. That 's
| about 10% of the worldwide emissions today.
| gedy wrote:
| If we actually get to that point, we'll eventually be
| doing a lot more activity and manufacturing off the Earth
| where the CO2 emissions don't matter.
| bigfudge wrote:
| Presumably co2 emissions in LEO would end up in the
| atmosphere though?
| throw4950sh06 wrote:
| One million launches per year seems to be adequate trade
| for 10% global emissions. This level of technology
| implies we are able to reduce emissions elsewhere.
| credit_guy wrote:
| I agree with you. I was just stating a fact, not
| criticizing.
| bigfudge wrote:
| I think it's ludicrously optimistic to think that this
| would substitute for reductions elsewhere. What possible
| mechanism could reduce 10% of global co2 emissions when
| many of these launches will be tourists and starlinks?
| throw4950sh06 wrote:
| 1 million launches per year implies at least a decade or
| two of development. There is a lot that can change in
| that time - for example energy production can move
| towards renewable and nuclear. Few decades more and we
| might get fusion too.
| pfdietz wrote:
| The limiting effect for Starship launches won't be CO2
| (direct air capture could counter that), it's injection
| of water into the stratosphere. Ballpark I think the
| limit would hit at about 100,000 launches/year.
| the8472 wrote:
| > Methane is better than all other fuels
|
| There are better fuels in terms of Isp and density. They
| have some downsides such as being corrosive or having
| highly toxic exhaust.
|
| https://x.com/ToughSf/status/1453391050681327622
| tuatoru wrote:
| Yeah, methane is kind of second best (or worse) in many
| parameters, but most importantly, it's cheap, abundant,
| and easily and safely storable and transportable, and it
| does the job.
| tim333 wrote:
| Also chosen as it may be possible to synthesize on Mars.
| throw4950sh06 wrote:
| And while not the reason, also on Venus! Venus seems like
| a very interesting colonization target - gravity almost
| like on Earth, and there is a place in Venus atmosphere
| where temperature is around 30 degrees Celsius and
| pressure is 1 atmosphere (Earth); and human air is a
| lifting gas in Venus atmosphere. As a bonus, interaction
| of Venus atmosphere with the Sun produces a magnetic
| shield.
| mr_toad wrote:
| > temperature is around 30 degrees Celsius and pressure
| is 1 atmosphere (Earth)
|
| And unbreathable and full of sulphuric acid. You may as
| well just stay in orbit.
| throw4950sh06 wrote:
| Staying in orbit means risk of catastrophic failure on
| puncture and doesn't provide access to the heat of lower
| layers of Venus atmosphere that can be used as energy
| source or carbon source. You also have to think about
| heat management - big colony means gigantic radiators.
| And most importantly no gravity and no magnetic shield -
| these make Venus imho better colonization target than
| Mars.
|
| On Venus, a puncture doesn't immediately destroy anything
| - because of equal pressure on each sides of the balloon
| wall. You have more than enough time to put on a
| protective coat and fix it.
|
| And building more living space is much easier + you could
| source the material (carbon) on site.
| tim333 wrote:
| I'd be a bit boring in your balloon above Venus though.
| At least on Mars you could wander around and check out
| the rocks or something.
| throw4950sh06 wrote:
| You are going to have hundreds of years of fun
| terraforming Venus... https://en.m.wikipedia.org/wiki/Ter
| raforming_of_Venus#/media...
| inglor_cz wrote:
| Massive. The designers of Starship studiously avoided all the
| problems that made Space Shuttle expensive to refurbish:
|
| a. Cheaper, more durable material (stainless steel).
|
| b. Cheaper, easier to manufacture engines.
|
| c. Easier to use fuel (methane is much "tamer" than
| hydrogen).
|
| d. Standardized heat shield with much smaller requirements
| for manual work.
| Tepix wrote:
| > d. Standardized heat shield with much smaller
| requirements for manual work.
|
| We'll have to see how it works out.
| inglor_cz wrote:
| It is a very daunting problem no doubt, maybe the hardest
| one, but I also don't doubt that the end form of Starship
| will require way, way less than 20 000 man-hours per
| turnaround (as the Space Shuttle required) to refurbish
| the heat shield. They simply cannot afford that.
| PaulHoule wrote:
| The way they are going they can try 5 different ones that
| fail until they find one that doesn't.
|
| Contrast that to the Space Shuttle which _required_ a
| human crew to flight test anything.
| _dain_ wrote:
| Manufacture and maintenance contracts for the Shuttle were
| deliberately spread out across many companies and states,
| especially in key congressional districts. It was a jobs
| programme; waste was a feature not a bug.
|
| Same thing for SLS.
| pfdietz wrote:
| More fundamentally, there _were_ contracts. SpaceX does
| things itself; there 's no legal friction internally. This
| gets back to the "Theory of the Firm" for why firms exist
| in the first place (transaction costs).
|
| The need to codify what work is to be done in contacts is
| antithetical to SpaceX's rapid development processes.
|
| https://en.wikipedia.org/wiki/Theory_of_the_firm
| pfdietz wrote:
| s/contacts/contracts/
| JumpCrisscross wrote:
| > _space shuttle was reusable_
|
| SpaceX builds vehicles. The Shuttle was "reusable" because
| they needed a term between the default for transportation
| capital expenditures ( _e.g._ trains, planes, cars and ships)
| and the modified missiles that defined post-War spaceflight.
| "Reusable" in the Shuttle's context meant months of
| specialist overhaul time and the cost of a Falcon 9 launch in
| SRB booster replacements alone [0].
|
| At the end of the day, in 2010, "the incremental cost per
| flight of the Space Shuttle was $409 million, or $14,186 per
| kilogram" [1]. ($591mm and $20,512 in 2024 dollars,
| respectively [2].) SpaceX's _prices_ per kg are around $3,170
| on Falcon 9 [3] and $1,520 for Falcon Heavy [4]. Starship
| should bring those costs below $1000.
|
| [0] https://forum.nasaspaceflight.com/index.php?topic=51959.0
|
| [1] https://en.m.wikipedia.org/wiki/Space_Shuttle_program
|
| [2] https://www.usinflationcalculator.com/
|
| [3] https://www.spacex.com/media/Capabilities&Services.pdf
| _LEO_
|
| [4] https://en.m.wikipedia.org/wiki/Falcon_Heavy _LEO,
| theoretical_
| vardump wrote:
| > Starship should bring those costs below $1000.
|
| It might even bring the costs below $100/kg.
| ben_w wrote:
| It might, but it's also at a scale where people can dust
| off the old plans for orbital rings and ask if this time
| the economics work out.
|
| (My guess is the economics are fine, but the politics
| would kill it on earth, so the moon or mars will get one,
| but that's just an interested amateur opinion).
| vardump wrote:
| Once you put something _big_ in the LEO, you 'll have to
| be able to boost its orbit indefinitely, because the
| orbit will otherwise slowly decay.
| DarmokJalad1701 wrote:
| That depends on how high the orbit is. If it is high
| enough, the decay will take centuries.
| ben_w wrote:
| IIRC, above something like geostationary they tend to
| decay _upwards_? Though the old orbital ring white paper
| wasn 't suggesting anything like that, this was an
| alternative to needing to go so high in the first place.
|
| (I may be misremembering or getting confused with a thing
| specific to tidal locking?)
| AdammadA wrote:
| I wonder if they could have an orbit high enough to move
| away from earth with some kind of drag cables dangling
| from them into low orbit to counter the outward movement.
| Would that work?
| dotnet00 wrote:
| You mean something like a skyhook?
| AdammadA wrote:
| Yes but no hook or anchor needed I'd assume. The cable
| alone in lower orbit would weigh enough to be pulled by
| gravity.
| lovecg wrote:
| These orbits have vastly different speeds though.
| Consider a high geosynchronous orbit vs. something like
| ISS which goes around the Earth in an hour or two.
| AdammadA wrote:
| but you are towing the cable and you'd only get so far
| down for the counteraction of force from gravity to pull
| on the cable. Would speed or friction on a cable be a
| problem.
| cjbillington wrote:
| That is indeed what you get with tidal forces - bodies
| closer than geostationary orbit lose angular momentum and
| decay inward, bodies further out steal angular momentum
| from Earth and move outward.
|
| I suppose the same effect is there with satellites much
| smaller than the moon, but it would be tiny.
| lucianbr wrote:
| The L in LEO means we're talking about orbits that are
| not very big.
| schiffern wrote:
| By definition, LEO extends up to 2,000 km. At that
| altitude orbital lifetimes can exceed 10,000 years.
|
| https://commons.wikimedia.org/wiki/File:Orbital_Debris_Li
| fet...
| ben_w wrote:
| Contiguous rings filling an entire orbit don't have much
| air resistance, and what little they do have is small in
| comparison to their momentum.
|
| But yes, eventually things decay.
| piombisallow wrote:
| If you have the infrastructure to build an orbital ring,
| you have the infrastructure to keep it supplied too
| pantalaimon wrote:
| There is some SciFi story about civilization collapsing
| and the survivors worrying that the sky will fall on them
| hidden in there.
| dyauspitr wrote:
| Gotta make the individual pieces small enough to mostly
| burn up completely on rentry.
| jaggederest wrote:
| Term of art for this is "design for demise", i.e. make
| everything of pieces small enough and materials ablative
| enough that there's less than 1 in 10k chance that any
| debris will survive to the surface.
|
| https://www.esa.int/Enabling_Support/Space_Engineering_Te
| chn...
| jvm___ wrote:
| Planned obsolescence but in a good way.
| Vecr wrote:
| Already exists, _Chasm City_ by Alastair Reynolds. They
| absolutely trash orbit by planning very badly and over-
| packing habitats.
| mr_toad wrote:
| Presuming it's in LEO. When and if we ever get around to
| building these things they probably won't be in LEO at
| least not for long. Some of them might not even be
| constructed from materials launched from Earth.
| Tepix wrote:
| How does the orbit or an orbital ring decay?
| adastra22 wrote:
| There are relatively stable orbits over the equator.
| HarHarVeryFunny wrote:
| The Shuttle consisted of the shuttle (orbiter) itself, the
| external tank (not reusable), and the two boosters which
| could be reused after ocean recovery. The orbiter itself was
| slow and expensive to reuse since (among other things) all
| the heat shield tiles were inspected and 30-100 replaced
| between each launch. I don't know how much work was done to
| the engines between launches, but SpaceX's parts and cost
| reduction on the Raptor engine have to give it an advantage
| there.
|
| StarShip consists of the Super Heavy booster that we saw
| "caught" today, and the StarShip (orbiter) itself. Having the
| booster return to launch site vs requiring ocean recovery
| should potentially increase cadence and reduce cost of reuse.
| StarShip is also meant to be reusable, although it remains to
| be seen how that will pan out. On the previous flight there
| was burn through from inadequate heat shielding - maybe we'll
| see an improvement with today's vehicle. I'd expect SpaceX to
| iteratively arrive at a quicker and more cost effective
| orbiter reuse procedure than NASA had with the shuttle, but
| how quick remains to be seen. Of course they are planning
| many of these to go on one-way trips to Mars rather than
| being reused.
| cubefox wrote:
| > The orbiter itself was slow and expensive to reuse since
| (among other things) all the heat shield tiles were
| inspected and 30-100 replaced between each launch.
|
| Worth noting that Starship's heat shield is very similar to
| the one of the Shuttle. They actually got the manufacturing
| method from NASA.
| philistine wrote:
| That's why I remain very skeptical about the easy
| refurbishing of Starship. Initially, way back around
| 2016, the plan was to vent liquids to create a cushion
| around the ship. That sounded more easily reusable.
| cubefox wrote:
| Yeah. I think they originally planned to use ceramic
| tiles only for certain spots and still transpiration
| cooling for the rest. Then they fully switched to ceramic
| tiles. In an interview with Everyday Astronaut on
| YouTube, if I recall correctly, Elon Musk said they first
| believed the ceramic tiles to be lighter.
| bryanlarsen wrote:
| Starship is supposed to be fully & rapidly reusable. Neither
| adjective applies to the space shuttle.
| inemesitaffia wrote:
| Read the article "SpaceX flight Ops"
| alemanek wrote:
| Falcon 9 has already proven that partial reusability is
| economical. SpaceX has dominated the entire worldwide launch
| industry and their competitors are nation states with no need
| to make a profit.
|
| The difference is that they have already proven to be the
| lowest cost and most reliable launcher due to reuse. This is
| them lapping the industry with second stage reusability.
| fastball wrote:
| Shuttle itself was refurbishable, but not rapidly re-usable.
| It was also incredibly expensive to build and refurbish. A
| shuttle launch also utilized boosters that were not re-
| usable.
|
| Starship is supposed to be (and clearly well on the way to
| being) _fully rapidly re-usable_. That means all stages (in
| this case two) are re-usable, and that the capital and time
| required to get either stage flight ready again after a
| flight should be minimal.
|
| Said another way - it is cheaper for SpaceX to build an
| entirely new Starship + Booster than it was to refurbish a
| Shuttle between flights, by a factor of about 4x ($90M for a
| Starship+Booster / $400m for Shuttle refurb).
| fpoling wrote:
| The boosters for the Shuttle were reusable, but it turned
| out the cost of refurbishing them was similar if not higher
| than simply building new ones. Plus it contributed to the
| Challenger crash, see "Mr. Feynman Goes to Washington",
| https://calteches.library.caltech.edu/3570/1/Feynman.pdf
| dyauspitr wrote:
| The difference is only a small part- the shuttle itself- was
| reusable. The booster that put it into space was scrapped
| every time.
| ErneX wrote:
| The boosters were not (or at least not with the quick
| turnover and lower costs like the ones from SpaceX)
| shoxidizer wrote:
| You've got a lot of responses on the difference of
| reusability, but the shuttle was also more expensive because
| it had to carry a lot of capabilities with it every time. If
| you were launching a satellite, you were carrying along the
| crew compartment and a couple astronauts. If you were
| bringing a few astronauts to the space station, you brought a
| cargo bay. And in either circumstance, you brought big wings.
| Starship can be filled with all cargo. And if you're just
| changing crew on the ISS, you could... not use Starship and
| launch a Falcon 9 instead. One of the mission profiles
| required by the Air Force for the shuttle was that it be able
| to rendezvous with a satellite, put it in the cargo bay, and
| return to Earth, all under 2 orbits and along a path that
| avoided flying over the Soviet Union, which required a rather
| large turn in-atmosphere to make it back to landing on the
| west coast.
| pfdietz wrote:
| One of the drivers was the need to Abort Once Around on a
| polar orbit launch from Vandenberg. The launch site rotates
| to the east during the orbit so cross range was needed. No
| such polar orbit launch (abort or otherwise) ever occurred,
| though.
| dangus wrote:
| To answer this oversimplified question with a simple answer,
| the Space Shuttle couldn't be a more different vehicle than
| this one. It truly is a comparison between apples and
| oranges.
|
| Let's start with the fact that it was designed in the 1970's.
| If you had a Cadillac DeVille from 1970 it would get 8-12
| miles per gallon. Just the mere fact that the design is about
| 70 years old makes that vehicle too expensive to operate, and
| that's before we even start talking about other issues with
| the design (performance, safety, reliability, etc).
| modeless wrote:
| The Space Shuttle was not fully reusable as the biggest
| single part, the orange tank, was destroyed every time. But
| more importantly, the orbiter and boosters needed 2+ months
| of refurbishment/rebuilding after every flight.
|
| One of the design goals of Starship is for the booster and
| ship to relaunch with zero refurbishment. To literally land
| over the launchpad, refuel, and go back to orbit within hours
| without people even approaching them. The heat shield is the
| biggest risk to that goal IMO, and we saw today that it
| definitely sustained serious damage despite improvements. But
| if they ever get there then per-launch costs will be a tiny
| fraction of the Shuttle with 6x the payload.
| sobellian wrote:
| The majority of damage to shuttle's TPS apparently came from
| foam strikes from the external fuel tank. Superheavy's
| optimized profile certainly helps here, since there are no
| large cryogenic tanks hanging ominously over the TPS while
| being shaken violently by solid rocket boosters.
| ijustlovemath wrote:
| No one has answered with one of the biggest issues with the
| shuttle: each one was extremely custom. Every single heat
| shield tile was unique to a specific position and a specific
| shuttle. There were probably over a hundred million
| individual components in the Shuttle, and with many critical
| ones being custom, the time to refurbish it for a new launch
| was much longer.
|
| This is in contrast to something like the falcon, which has a
| very standardized mfg process and components, which allows
| for really rapid iteration
| cryptonector wrote:
| The shuttle wasn't fully reusable, just for starters. The
| boosters were reusable with a lot of refurbishment work. The
| center tank was expended every time. It was very expensive.
| Only five shuttles were ever made, which means that no effort
| was put into automation of production of engines etc.,
| everything was custom, and everything required great care to
| save the sunk costs.
| slashdave wrote:
| Early designs of the shuttle were fully reusable. That was
| quickly dropped due to costs and requirements. The final
| shuttle design was also unsafe.
| dools wrote:
| Because people are reflexively averse to government spending
| unless there's a billionaire making profits on the way
| through thanks to 100 years of academic capture by Austro-
| libertarian economists.
| CaptainFever wrote:
| This is an anti-intellectual conspiracy theory. Mainstream
| economics no longer operate using schools of thought: https
| ://www.reddit.com/r/AskEconomics/comments/quxwl5/how_is...
| dools wrote:
| No, if anything it's an anti intellectual conspiracy
| kovvy wrote:
| Reusability increases costs if you don't reuse often enough.
|
| The shuttle would have been much, much, cheaper per launch if
| it had flown more often. The expected costs for the shuttle
| included a range based on how often it flew which turned out
| to be reasonably accurate. They were much worse at predicting
| which end of the range they would be flying in. At the rate
| they ended up flying they had the extra costs of reusability
| without any of the benefits.
|
| Starship is ludicrously expensive, but still much cheaper
| than even the best case for the Shuttle, and it has a
| guaranteed source of launches to help it benefit from
| resuability.
| jondiggsit wrote:
| I've read that a shuttle refit after landing was so
| expensive and time consuming to render it useless.... Feel
| free to correct if wrong.
| pfdietz wrote:
| And, the market projections that indicated there would be
| enough payloads for large amounts of launches were also
| basically fraudulent.
| walrus01 wrote:
| Estimated costs of the fully loaded cost of the shuttle
| program ended up at $600 million to $1 billion per flight.
| The refurbishment costs per flight and man hours/staffing
| were astronomical.
|
| It actually would have been a lot cheaper if they had gone
| for serialized, mass assembly line production of Saturn V
| class disposable rockets to launch piece of space stations,
| satellites and manned missions into low earth orbit.
| jonplackett wrote:
| The main thing is... Space shuttle wasn't all that reusable.
| It had to be launched with a massive rocket and two massive
| boosters that just fall into the ocean.
| GuB-42 wrote:
| > What is the differences between the two?
|
| More than 40 years and many lessons learned.
|
| SpaceX took advantage of tech from both the US and Russia,
| including the experience with the Space Shuttle. They have
| better computers, better metallurgy, advanced 3D printing and
| their own experience with the Falcon 9.
|
| There is no guarantee that it will reduce the costs that
| much, but will all that experience, the chances are success
| are higher than with the Space Shuttle.
|
| One big issue that isn't talked about much and that SpaceX
| takes very seriously is simply a lack of demand. There is
| only so much stuff you want to put in space. Satellites are
| expensive, and even with disposable rockets, the launch is
| only a smaller fraction of the cost. It is already a problem
| with the Falcon 9 as they have a bunch of rockets and not
| much to do with them. Starlink, orbital refueling, and crazy
| ideas like earth to earth transport are all ways to address
| this problem.
|
| It was a problem for the Space Shuttle too, they couldn't
| achieve the economies of scale they planned it for. It was
| supposed to fly for routine maintenance missions but it
| didn't work out.
| pfdietz wrote:
| > lack of demand
|
| What this also means is that if you want to get into the
| space economy, work on things to do in space, not yet
| another launch vehicle startup.
| interludead wrote:
| This opens up immense possibilities for exploration
| le-mark wrote:
| I'd love to see a probe catch and examine `Oumuamua.
|
| https://en.m.wikipedia.org/wiki/`Oumuamua
| k4rli wrote:
| Where is the progress if they're 2 years behind their schedule?
| In Q1 2025 they should already be launching the HLS according
| to the timeline.
| Dr4kn wrote:
| Falcon 9 is still the most advanced rocket flying real
| missions to date. The only thing close to it is Blue Origin,
| which didn't even have their maiden flight yet.
|
| Is their timeline too optimistic? Yeah, but if the industry
| still catches up with F9 and they are close to having
| something a lot more advanced it really doesn't matter.
|
| Even without reusability nothing comes close to Starship's
| cargo capacity. If you don't have to put a lot of engineering
| into getting things as small and light as possible you can
| put things in space a lot faster.
| pfdietz wrote:
| And, eventually, if it becomes cheap enough to put people
| in space for the task, you can plan to actually maintain
| things there rather than design for extreme reliability.
| autonomousErwin wrote:
| That was crazy, 50% of me thought as it was coming in, especially
| as it pitched towards the tower, "they've overcompensated and are
| going to bring the whole tower down" but they absolutely nailed
| it.
| phkahler wrote:
| Yeah but they did pass some flame down much of the tower.
| Pretty quick though, probably just cleaned it with fire.
| ivanjermakov wrote:
| Saving up those refurbishment costs, cleaning the tower ahead
| of time!
| foobarian wrote:
| Even without the catch step, I always feel like their boosters
| are coming down way too fast way too late, with engines
| reigniting startlingly close to surface. Never ceases to
| surprise me.
| hobofan wrote:
| Yeah, it also always catches me off guard how late they
| reignite, while at the same time I'm always surprised by how
| slow the liftoff is even though all the boosters are on full
| throttle. Of course both things make sense given the
| respective mass at both points in the process, but given that
| it looks like the same rocket from the outside, a bit
| unintuitive.
| mshockwave wrote:
| I have the same feeling watching Starship when the telemetry
| on the bottom right of the screen showing "0km" but landing
| burn hasn't started. Later did I know that it was meant to
| start the burn only a few hundreds _meters_ from the ground
| cubefox wrote:
| It may also be that the video feed is delayed (e.g. due to
| compression) relative to the telemetry.
| grecy wrote:
| Prior to today the only landings you've seen are Falcon 9,
| which has to do a "hoverslam" because it can't throttle low
| enough to actually hover.
|
| Even just one engine in minimum thrust would make the rocket
| go up when empty.. so the computer lights the engine at the
| precise right moment so it will have 0 velocity at 0
| altitude, then it cuts off the engine. "Hoverslam".
|
| The Starship booster is different, it can actually hover.
| lutorm wrote:
| Every moment your engines are burning at anything less than
| maximum thrust, you are wasting fuel. You want to relight as
| late as possible with as high thrust as possible for maximum
| efficiency. But that it actually works is nuts.
| irjustin wrote:
| PEDANTIC - max efficiency isn't necessarily tuned to max
| thrust.
| pfdietz wrote:
| The higher the thrust, the lower the gravity losses.
| Gravity losses go down as you approach orbital speed but
| they aren't zero until you're in orbit. And when boosting
| out of orbit, the higher you are the less benefit you get
| from the Oberth Effect, so you want to do the burn before
| you rise too much, which implies sufficient thrust.
| lutorm wrote:
| Exactly. In addition, by delaying the relight as long as
| possible you're giving drag as much time as possible to
| do the work for you (assuming you're not at terminal
| velocity, so not applicable for the ship.)
| rtkwe wrote:
| The math is pretty intuitive; every second you're burning
| is another 9.8 m/s of delta V you have to spend
| counteracting gravity instead of slowing the craft down
| (minus air friction) so minimizing deceleration time cuts
| your fuel expenditure massively. It also means you have
| to carry less fuel so you weigh less and you spend less
| fuel for the same acceleration. It's the inverse of the
| rocket equation really, less mass is easier to slow down
| and you waste less energy (ie fuel mass) decelerating
| faster.
| left-struck wrote:
| I remember playing KSP, I had used some mod to program a
| moon lander to do a suicide burn, a maximum thrust burn to
| land. I did the maths myself and when it actually came to
| the landing I was 100% certain I had either a bug in my
| code or did the math wrong because I was coming in way too
| fast, or so it seamed, but to my surprise the thing slowed
| down in time! Mind you ksp is way simpler than the real
| world and the spaceship could handle some... error, the
| landing was hard but successful
|
| Point is it always seems like you're coming in too fast
| Havoc wrote:
| Yeah it definitely looked sketchy for a sec but was probably
| fully as intended
| dmix wrote:
| Video of the catch
|
| > Mechazilla has caught the Super Heavy booster!
|
| https://x.com/spacex/status/1845442658397049011
| aaronharnly wrote:
| Naive question: I obviously expect there to be flames from the
| engines, but there were flames on the lower sides for quite a
| while after the catch - is that expected?
| thepasswordis wrote:
| My guess is that it's venting out the system pressure, and
| it's safer to burn it.
| sourcecodeplz wrote:
| who cares... they did it and it didn't burn up or destroy the
| platform. rest is just nitpicking
| swarnie wrote:
| Outside of maybe Boeing "who cares..." isn't a valid answer
| in engineering.
| panick21_ wrote:
| [flagged]
| ethbr1 wrote:
| It's an interesting engineering question, not a slight.
|
| Obviously the primary mission was successful, in spite of
| anomalies (good system design!), but people are and
| should be curious about this aspect.
| tonyarkles wrote:
| There's a bunch of people crapping on you who clearly
| haven't been through a flight test campaigns.
|
| 100% with you. The teams I've worked with would be
| celebrating and trying to figure out what's burning at
| the same time. And especially trying to figure out if
| there's anything that they need to do to collect evidence
| for that investigation (eg zooming the remote PTZ cameras
| in on specific areas or things like that)
| dang wrote:
| Please don't respond to a bad comment by breaking the
| site guidelines yourself. That only makes things worse.
|
| https://news.ycombinator.com/newsguidelines.html
| kiba wrote:
| It's a prototype.
| ben_w wrote:
| That's why it's not a catastrophe that something was
| unexpectedly on fire, not a reason to dismiss the
| question.
| jjk166 wrote:
| So the whole purpose of it is to identify issues to be
| resolved.
| Denvercoder9 wrote:
| > who cares...
|
| I bet SpaceX does. They've solved the big problems, now
| it's time to solve the small problems and make reuse a
| reality.
| haliskerbas wrote:
| Isn't this a forum of hackers caring about the news?
| Everyone seems excited here and that excitement naturally
| leads into curiosity for many who identify as hackers.
| ceejayoz wrote:
| You usually see some down near the engines after a Falcon 9
| landing.
|
| The vent out the side before touchdown didn't look right,
| though. Something blew, but non-critically.
| dotnet00 wrote:
| Probably not expected, but the nice thing is that they don't
| have to pull the vehicle off the bottom of the ocean to study
| what happened there.
| exitb wrote:
| Desirable? Probably not. Expected? Yeah. Especially given
| that is the was pretty unexpected to work on the first try.
| tankenmate wrote:
| It does look like venting, but on the Everyday Astronaut
| video feed it also looked like a COPV inside one of the
| strakes looked like it exploded as well.
| inglor_cz wrote:
| If not an intended vent, probably some methane leak. Given
| that they have the first stage intact, they will know exactly
| what happened very soon. Yet another advantage of having the
| rocket returned instead of sinking it in the ocean.
| generuso wrote:
| It is common for Starship prototypes to have uncontrolled
| fires, but it is obviously not a good thing.
|
| For example, prototype number 10 exploded 8 minutes after
| landing [1] because of a seemingly insignificant fire at the
| bottom.
|
| After today's flight there was a long lasting fire in the
| engine section, with occasional flaming pieces of plumbing
| raining down from the rocket. Examining the aftermath should
| help SpaceX to understand what improvements need to be made
| to prevent this from happening.
|
| [1] https://youtu.be/XOQkk3ojNfM?t=38346
| ls612 wrote:
| This same issue was common on early Falcon 9 landings and
| took a while to fully eliminate.
| mrandish wrote:
| This highlights another thing I love about watching
| SpaceX's unprecedented rate of progress. They're managing
| the complex balance of risk, learning, time and budget
| extremely well. I'm not an expert in the relevant domains
| but even I've noticed and appreciated that the typical
| SpaceX development test always manages to get big chunks of
| new data, while still having some notable things not quite
| working.
|
| It's an object lesson in rapid engineering development. If
| everything goes perfectly in a development test, it's a
| sign you're not moving fast enough (meaning not taking
| enough risk per increment to maximize learning). As
| valuable as Falcon, Starlink and Starship are, the biggest
| near-term value of SpaceX may be providing such a clear
| demonstration of well-executed "fail fast, learn fast"
| engineering that even politicians and bureaucrats can
| understand it.
| ericcumbee wrote:
| Scott Manley said it was a purposeful flare off of methane
| to prevent over pressureization.
| generuso wrote:
| Maybe the flare on the side started as purposeful. But
| there was also a fire inside, between the engines, with
| flaming pieces of some pipes or cables raining down from
| the rocket. You can see one example of this just after
| this timestamp: https://youtu.be/YC87WmFN_As?t=12928
| ericcumbee wrote:
| Yeah i see what you are talking about now.
| zitterbewegung wrote:
| They have mission goals which were achieved (booster was
| caught). Goals that they didn't think they could do (Starship
| being within the buoys). While there was flames and those
| could be dangerous you judge the mission based on the planned
| outcomes but they will try to eliminate the anomalies to
| improve the next mission while still achieving the goals.
| tempestn wrote:
| The thing is that no one is judging the mission based on
| this imperfection. It's just intellectual curiosity, which
| is a good thing. The comments that are getting down voted
| are all assuming some negative motive that just isn't
| present.
| lexicality wrote:
| It looked to me like the fire was on the fuel intake valves
| and if you watch carefully that area was scoured by the
| nozzle output when it was first slowing down so it probably
| blew through the shutoff valves or something
| rkagerer wrote:
| I'd love to see followup analysis of what that fire was all
| about.
| cryptonector wrote:
| In some of the views of the landing it's clear that the
| flames are from a methane vent. I.e., it's really not a
| problem.
| gizajob wrote:
| Amazing achievement.
| credit_guy wrote:
| I wonder what will happen when they get to 99% reliability?
| They clean up and rebuild the Mechazilla every once a hundred
| catches, on that occasion that one fails?
| bombcar wrote:
| I suspect there's already a whole "refurbishment" process for
| the crane even for non-reusable launches, and once it's
| working darn reliably, they can just have a bunch of them
| ready to go, and cycle once in a while.
| creer wrote:
| The next one is already mostly built and very different
| from this one. They move fast.
| bufo wrote:
| The plan is to have many, many Mechazillas.
| brianwawok wrote:
| I also expect if something fails a test in the way down you
| crash in the water rather than splat your catcher
| dotnet00 wrote:
| The booster aims towards the shore until the landing burn
| starts, only then does it swing towards the tower. So, for
| the most part, failures should mean that the booster safely
| crashes into the water.
| slashdave wrote:
| That, and redundancy. The amount of cash you save allows you
| to do that.
| ls612 wrote:
| They've landed over 300 Falcon boosters and haven't wrecked
| their barges yet I expect that this won't be a major issue.
| nomilk wrote:
| 10 minutes from 3h25m of this video shows launch and catch.
|
| Historic viewing :)
|
| https://www.youtube.com/watch?v=YC87WmFN_As&t=3h25m14s
| afh1 wrote:
| This angle is even more impressive IMO
| https://x.com/kimbal/status/1845451222750306344
| nilsherzig wrote:
| It's very impressive to see the buildings next to it, the
| original video lacks any sense of scale
| cubefox wrote:
| You can hear Elon Musk in the background.
| mncharity wrote:
| A phone video[1] from Mexico, with nice plume refraction of the
| Sun.
|
| [1] https://x.com/Cosmo_556/status/1845554958604657051
| sourcecodeplz wrote:
| Damn what a time to be alive! Amazing
| teractiveodular wrote:
| It's difficult to overstate how important the milestone of
| catching the booster is. Now we have a reusable rocket an order
| of magnitude larger than anything we've had before, and the cost
| of kg to orbit just nosedived.
| HarHarVeryFunny wrote:
| I'm not sure how critical "catching" the booster is to
| reusability, but it does save weight by not needing legs for
| landing, and perhaps the booster suffers less stress this way?
|
| Note that the booster is not really being "caught" although
| this is the word it seems we're stuck with. It's really more
| like landing on the arms, since it throttles to a hover at that
| point.
| mshockwave wrote:
| I think saving weight is definitely one of the main issues,
| see those proportionally large legs on Falcon-9, I guess it
| simply doesn't scale on bigger vehicles like Starship / Heavy
| booster. Also, by catching the booster on site, they can even
| save the transportation and do the refurbishing on site, so
| even shorter turnaround time I guess.
| pfdietz wrote:
| Also, saving on damage to the landing pad.
| chasd00 wrote:
| That's a good point, they used the sprinklers on landing
| to mitigate damage to the pad and the booster was caught
| well off the ground.
| cubefox wrote:
| Another way to save weight would be to make the booster out
| of carbon fiber instead of steel. I wonder whether they
| will do that eventually.
| Denvercoder9 wrote:
| > I'm not sure how critical "catching" the booster is to
| reusability
|
| Not necessarily for reusability, but it helps significantly
| for rapid reusability: it eliminates the need to transport
| the booster from the landing site to the launch site. Given
| that it's 9m x 70m and weighs 270 tonnes, that's not an easy
| process.
| newsclues wrote:
| Efficiency and cost are the goals, reusability is just one
| way to do that. Moving big heavy things less is another.
| cryptonector wrote:
| > but it does save weight by not needing legs for landing
|
| That was the exact reason they went this way.
| shirro wrote:
| Second stage reuse seems the far more challenging problem.
| Other companies should have reusable boosters soon but if
| significant amounts of Starship continue to ablate on the way
| down they could be faced with a disposable Starship competing
| with smaller and cheaper second stages that are well sized for
| typical payloads. We already knew boosters can be flown back to
| launch sites reliably with high accuracy. We don't know if it
| is possible to make rapidly reusable thermal protection systems
| that can operate on an orbital vehicle of Starship's size until
| it is demonstrated.
| api wrote:
| Didn't they look at all kinds of ideas earlier like squirting
| some propellant or water out over the skin on the way down,
| and wasn't steel chosen for its thermal robustness? Did they
| get into the problem and realize it's a lot harder and
| abandon those things for tiles?
|
| Maybe they will have to sacrifice more payload mass for
| active or passive shielding or more fuel for powered
| deceleration. That would yield a less impressive lifter but
| with full reusability.
| chasd00 wrote:
| Yeah for rapid reusability tiles aren't going to work, too
| fragile. Iirc it was with a lot of reluctance they went
| with tiles and will have to make breakthroughs on the heat
| shielding to get where they want to be.
| cma wrote:
| Inspection might be easier with computer vision advances
| since the space shuttle.
| api wrote:
| Also with a saner design. The shuttle had a complicated
| shape with every tile being almost unique. It was nuts.
| cma wrote:
| I think starships are too now to save weight where they
| get different thermal loads.
| m4rtink wrote:
| IIRC they still have most of the tiles be the same, with
| just a few variants for tricky places.
| rini17 wrote:
| They already plan refueling infrastructure in orbit. That
| would include stuff to "squirt" on the way down if
| necessary. If they can use one extra launch to reuse 5-10
| starships that might be interesting. Noone knows yet if
| it's actually needed.
| wolf550e wrote:
| They dropped transpiration cooling, at least for now.
| WalterBright wrote:
| Interestingly, the inside surface of a rocket nozzle is
| covered with tiny holes. Fuel is circulated in a jacket
| around the nozzle both to pre-heat the fuel and to cool the
| nozzle. Additional cooling of the nozzle comes from fuel
| leaking into the combustion chamber through those holes,
| carrying away the heat so it doesn't melt the nozzle. It's
| called boundary layer cooling.
|
| It was one of the technological breakthroughs of von
| Braun's team with the V2.
| philistine wrote:
| > Other companies should have reusable boosters soon
|
| You're way too optimistic. Starship will deliver commercial
| payloads, with SpaceX phasing out Falcon 9 outside of ISS
| launches, before anyone has a reusable Falcon 9 equivalent.
|
| It pains me to say this, but SpaceX is in a class all its
| own.
| thinkcontext wrote:
| The Chinese could have a reusable booster before then. One
| of their companies is doing 10 km hop tests.
| signatoremo wrote:
| SpaceX couldn't manage the first Falcon 9 landing until
| 2015. The first Falcon 9 reuse wasn't until 2018, so 3
| years to achieve reusability. The Chinese prototype
| hasn't yet succeeded at sub-orbital landing. I wouldn't
| be surprise if it'd take them longer than 3 years to have
| a reusable rocket. Starship would have been routine at
| that time.
|
| Blue Origin plans to launch New Glenn in a month, with
| landing planned. They are a wild card.
| jiggawatts wrote:
| I'm not _saying_ they stole the plans through industrial
| espionage, I'm just wiggling my eyebrows suggestively
| while glancing in the direction of the suspiciously
| similar looking booster.
| ls612 wrote:
| Is this the same company that had their booster fly into
| the air when they were trying to _static fire_ test it?
| jiggawatts wrote:
| They must have forgotten to steal the plans for the hold
| down clamps.
| m4rtink wrote:
| Well, that kinda shows a potentially another speed
| "advantage" - less paperwork and reduced safety
| requirements.
| Kerb_ wrote:
| I promise you the fancy technology is in the electronics,
| software, and implementation, and not the fact that the
| cylinder with legs looks like another cylinder with legs
| adastra22 wrote:
| It's a literal clone of starship, down to the flaps and
| grid fins.
| Tier3r wrote:
| Chinese startups have historically been the only ones to
| be able to move as fast as Musk. One very underrated
| ability of Tesla is they can develop new products in 2-3
| years from conception to market. The only other car
| companies to do it at scale is BYD, Nio and Xpeng. The
| company he is talking about is probably LandSpace. They
| got from conception to hop test in what seems to be 5,
| maybe 4 years. SpaceX took 7.
| shirro wrote:
| I think China has about 5 companies working on reusable
| launch and it is part of a national government strategy.
| People can argue about the timeline but it is inevitable.
| dotnet00 wrote:
| New Glenn finally has flight hardware undergoing pre-flight
| testing. I think they're pretty likely to manage to fly in
| early/mid 2025, and they do aim to recover the booster in
| their first try.
| WalterBright wrote:
| Why does it pain you? Musk's SpaceX has produced several
| enormous advancements in space technology.
|
| SpaceX is one of the greatest, if not the greatest, private
| technology company in history.
| andrewstuart2 wrote:
| I think it pains some of us to say it because of the
| person Musk has turned out to be, which is the opposite
| direction I think many of us were hoping his character
| development would take him.
| WalterBright wrote:
| What terrible thing has Musk done?
| jiggawatts wrote:
| Supported Trump.
| WalterBright wrote:
| The Democrats have a sad history of denigrating Musk,
| which is likely why he changed from being a Democrat to a
| Republican.
| jiggawatts wrote:
| You don't spend that kind of money and risk alienating
| your entire customer base (and future workforce!) just
| because of a slight.
|
| Musk is getting something from Trump: most likely
| protection from some legal issue.
| WalterBright wrote:
| It was more than a slight. Biden pointedly ignored Tesla
| when conducting an EV summit and handing out subsidies.
| Then there was the FCC fiasco where the FCC snubbed
| Starlink.
| altcognito wrote:
| What subsidies did Tesla not get?
| tsimionescu wrote:
| > Then there was the FCC fiasco where the FCC snubbed
| Starlink.
|
| You mean that time that the FCC removed Starlink from the
| broadband problem when they couldn't deliver the speeds
| that they had committed to, as defined very explicitly in
| the program?
| altcognito wrote:
| Musk has _never_ , no matter what he claims, ever a
| progressive democrat. He would be at best, someone who
| believed in the liberalization of certain drug policies.
| His economic beliefs have _always_ been max pro business
| (aka, hands off, anti labor). He solidly fits under
| libertarian like the rest of the tech billionaires.
| Republicans, if it weren 't partly driven by Christian
| fundamentalists, would be libertarian. The conservative
| GOP party of the 70's hasn't existed in decades.
| brianmurphy wrote:
| I think that is only part of it. Musk gave an interview
| where he talked about how the woke medical establishment
| trans'd one of his kids. They falsely told him to do the
| transition or his child's death was a near certainty.
| European countries are now restricting this "treatment"
| for children. The US has been slow to follow. There is a
| lot of money and political pressure from the left to keep
| the medical intervention industry alive.
| philistine wrote:
| Are you aware of what you're doing: you're removing
| agency from that person who transitioned. They're
| abundantly public about how their transition was
| appreciated and needed. Do you ultimately care more about
| the feelings of your own dad over yours?
| trealira wrote:
| A few things that I (as someone who doesn't follow
| Twitter) have heard about from anecdotes and from the
| news about why people dislike him:
|
| - He called some guy who worked for him a pedo for no
| reason, which he was sued over
|
| - Took over Twitter and promoted right wing tweets to
| everybody, unbanned far right accounts and sued critics
| who said he did so
|
| - Started promoting far right ideas, like when he
| retweeted "Interesting" to some tweet of a 4chan post
| saying that high-status, high-testosterone males are the
| only ones who can think freely and should be the only
| ones who can vote
|
| - Took the side of the right-wing rioters who attacked
| mosques in the UK, saying civil war is inevitable
|
| - Just seems to insult companies for little reason -
| advertisers who leave him, and Apple
|
| There has been kind of a slow back and forth. Some people
| who liked him were miffed about the pedo thing, but they
| didn't hate him. But he has just kept doing things that
| some people hate.
| hash9 wrote:
| > Took the side of the right-wing rioters who attacked
| mosques in the UK, saying civil war is inevitable
|
| Leave out the part where the riots were started because
| someone with an immigrant background killed a bunch of
| kids at a Taylor Swift concert and police were
| withholding the identity. Along with your other
| 'anecdotes', can you make your political position any
| more transparent?
| trealira wrote:
| I see I accidentally came off implying that I'm
| disaffected and take no sides - most of the time, right
| wing politics seems abhorrent to me. Those are the main
| things I remember because left-wing spaces tend to hate
| him, and I dislike him because of those things, but no
| more than CEOs of companies like Nestle, which has
| engaged in things like slavery and child trafficking.
|
| > because someone with an immigrant background killed a
| bunch of kids at a Taylor Swift concert and police were
| withholding the identity.
|
| It might be somewhat justified if they burnt the house
| down of the murderer, or those who assisted him. They
| didn't - they burnt down houses, shops, and mosques,
| because they wrongly assumed the guy was Muslim and
| decided that was just cause to target any Muslim. His
| identity was hidden because he was a minor at the time of
| the attack.
| ZeroGravitas wrote:
| Yeah, he's like a cross between Henry Ford and Werner Von
| Braun...
|
| and coincidentally he makes cars and rockets too!
| asadotzler wrote:
| Wildly incorrect. New Glenn is already here.
| mkl wrote:
| No it isn't. It might be soon in some early way: "the
| first launch is expected to take place no earlier than
| November 2024", "The booster for the flight is named _So
| You're Telling Me There's a Chance_ , alluding to the
| difficulty of landing a reusable booster on the first
| attempt." -- https://en.wikipedia.org/wiki/New_Glenn
| audunw wrote:
| I found Jeff's Bezos interview with everyday astronaut really
| illuminating on this topic.
|
| Supposedly they're working on both a reusable and cost
| optimised non-reusable second stage at the same time. And
| they don't really know yet which one will end up being
| cheaper.
|
| You also see this kind of thinking with Rocket Labs neutron
| rocket. Where they focus on making the reusable booster do
| more, while making the second stage smaller, cheaper and
| simpler.
|
| I think if it wasn't for the rocket engine this wouldn't be a
| question at all. The tank doesn't have much value. It's just
| a thin shell and probably a fraction of the cost of the fuel.
|
| So I'm thinking, perhaps the optimal solution is something
| like this: the bottom part of the second stage with the
| engines separates, and a small engine and fuel tanks places
| the engines in a stable orbit. The tank itself is deorbited
| and burns up.
|
| At some point later something like the Starship collects
| several second stage engines and deorbits them safely to be
| reused.
|
| Or perhaps just the engines can be immediately deorbited with
| an inflatable heat shield and parachutes.
| cryptonector wrote:
| > Second stage reuse seems the far more challenging problem.
|
| Sure, SpaceX has been doing first stage reuse for a long time
| now. But they have demonstrated landing the second stage
| successfully at sea twice now with the same sort of
| smoothness that they demonstrated once for the booster before
| they then caught the booster on the first real try.
|
| A partial list of unbelievably hard things that SpaceX has so
| far made seem easy: - building a rocket from
| scratch - landing Falcon 9 boosters - landing
| Falcon 9 boosters *reliably* - 3x weekly launch cadence
| (Falcon) - the bellyflop manoeuver - mass
| manufacturing(!) a rocket engine - catching the booster
| - simulated landings of the ship
|
| Catching the booster is really just like landing a Falcon 9
| booster w/o legs, but clearly much harder.
|
| Anyways, if they can do all those things then it's pretty
| clear that they can catch-land the ship.
|
| There's still a huge list of crazy-difficult things that
| SpaceX say they want to do that are hard to believe are
| possible, except for the fact that SpaceX has already done so
| many unbelievably difficult things already.
| pfdietz wrote:
| The hard part of 2nd stage reuse is surviving entry at
| orbital speeds. They are close to having that solved.
| m4rtink wrote:
| Yeah, I would say they already made a lot of progress -
| looked a lot less crazy now compared to the previous
| flight. :)
| pfdietz wrote:
| With F9, they piggybacked refining S1 recovery/reuse onto
| commercial launches. This was a big help in reducing
| development cost.
|
| They could do the same thing with S2 recovery here.
| cryptonector wrote:
| I would say they are there. Sure, they're having some
| burn through on the flaps, but they managed to hit their
| virtual landing spot anyways, and if they caught a
| slightly damaged ship they could study that damage
| better, repair it, and refurbish the ship.
|
| But I imagine that by IFT6 they'll have nailed the flap
| burn through problem.
| rtkwe wrote:
| They can't have burn through like that and achieve the
| kind of rapid reuse Starship needs to be useful outside
| low to mid Earth orbit, to go outside of there it
| requires a large number of flights to refuel the one
| Starship that will go on to Moon/Mars. Without the
| ability to refuel for Moon or beyond trips Starship is
| trapped in LEO/MEO because it's hauling around so much
| extra mass for it's own reusability.
|
| IMO a better use for it might be to ferry up large pieces
| of purpose built craft with less excess dry weight. A
| single reusable Starship launch can put the entire mass
| of the Apollo craft needed to make it from LEO to the
| Moon and back into LEO. Put a craft in two launches and
| dock it in orbit and you've got a huge capability to put
| a lot of mass onto the moon and still use the cheap cost
| to orbit Super Heavy gives.
| cryptonector wrote:
| At the rate at which SpaceX makes progress, that flap
| burn-through is a non-issue.
| shirro wrote:
| They have a history of pursuing solvable problems and
| abandoning those that were not working out or had better
| alternatives. Parachute recovery of the booster was
| abandoned in favor of propulsive landings. Catching
| fairings was abandoned for water proofing. Proposed Falcon
| and Dragon variants were abandoned as was Dragon propulsive
| landing. They abandoned carbon fiber construction and
| multiple concepts for Starship/Heavy.
|
| The tiles in combination with ablative materials and the
| insane robustness of a steel vehicle is sufficient to get
| Starship through re-entry and soft land in the ocean. We
| know ceramic thermal tiles worked on Shuttle and X37B and
| presumably will on Dreamchaser so while the success was an
| awesome achievement it wasn't unlikely given time to refine
| their methods.
|
| SpaceX are limited by the properties of real materials, not
| their ambitions, and we still don't know if rapidly
| reusability is possible with ceramic tiles or if their
| fragility will require inspections and refurbishment. They
| can't do it with ablatives and there aren't many other
| options. I am optimistic but also realistic about the
| difficulties of what they are attempting. Sometimes risky
| projects run into brick walls and you don't know what is
| possible until you try.
| cubefox wrote:
| If the ceramic tiles aren't working out, I think they
| could try transpiration cooling (previously planned for
| Starship) or a metallic heat shield (was planned for
| VentureStar). Or some combination. There seem to be quite
| a few options.
| cwillu wrote:
| They landed an earlier version of the second stage on the
| ground a few times as well. It's the atmospheric reentry
| from orbital velocity that currently necessitates the
| safety of a splashdown: they're not going to risk bringing
| a damaged and potentially uncontrollable vessel down over
| land, even if they could nail the landing with an undamaged
| ship.
| stevage wrote:
| They're a long way from having a reusable super heavy booster.
| It's still copping a lot of damage on the landing.
| throwaway4aday wrote:
| true but don't forget this is test flight #5
| interludead wrote:
| It's a game change
| rtkwe wrote:
| They're still having some significant burn through problems on
| the upper stage fins during reentry it looks like. Way better
| than last time but the top part of the fin was glowing far a
| while after the main reentry finished.
| pfdietz wrote:
| Even with a disposable upper stage, I believe Starship would
| be cheaper per kg than F9 or FH.
| rtkwe wrote:
| Maybe. Kind of impossible to know until we see launch costs
| but you could make a much cheaper upper stage than they
| have if you wanted disposable. Trick with that is you need
| a payload heavy enough to justify it. Has SpaceX talked
| much about a disposable upper stage version of the system?
| kvakkefly wrote:
| That was soooo good!
| redserk wrote:
| The SpaceX engineers are incredible for being able to pull this
| off.
| themgt wrote:
| NSF video:
| https://x.com/nasaspaceflight/status/1845442658203734384
|
| Truly incredible. A day for the history books.
| alecco wrote:
| > NSF is not affiliated with NASA, but the initials in the URL
| are used with permission from NASA.
| cubefox wrote:
| They should just rename themselves to NSF Space Flight, or
| NSF for short.
| ghc wrote:
| Nothing could have prepared me for how that catch looked. I was
| sure the rocket was careening into the tower at the last second
| before it straightened out. The control algorithms must be
| incredible for the landing system to work within those small
| tolerances.
| starspangled wrote:
| That was one of the greatest things I've ever seen.
| marssaxman wrote:
| Literally brought me to tears, watching that happen.
| ellipticaldoor wrote:
| Can you explain why? I don't understand why this is so
| important
| starspangled wrote:
| I certainly can explain it, I'm just not sure I can do it
| in a way that you could understand. If you yell me what's
| one of the greatest things you have seen and why, I might
| be able to better relate.
| monkeydust wrote:
| Watched several times, amazing stuff.
|
| Had flashbacks to playing Jupiter Landing on the C64!
|
| https://en.m.wikipedia.org/wiki/Jupiter_Lander
|
| Edit: SpaceX should create a simple 'catch' the rocket game.
| Play in browser style. Just for kicks and marketing.
| miyuru wrote:
| > Edit: SpaceX should create a simple 'catch' the rocket
| game. Play in browser style. Just for kicks and marketing.
|
| there is, it was discussed in the FAA thread.
|
| https://news.ycombinator.com/item?id=41821220
| renewiltord wrote:
| This is a pretty fun game. Not so easy. Good job to the
| creator for having added some mechanics that make it work.
| dominicdoty wrote:
| Shameless plug for my own project with a similar bent - write
| your own lunar lander autopilot in browser
|
| lunar.unnecessarymodification.com
| demarq wrote:
| very fun got 51! with fuel limit + mass enabled.
| poorlyknit wrote:
| Very cool :) I got a good enough score in the basic
| scenario by playing around a bit but it would be cool if
| you could link some kind of tutorial (e.g. to a digital PID
| video or something like that).
| demarq wrote:
| so now managed to save 63% fuel, but score doesn't seem to
| take this into account (still 51)..
| sobani wrote:
| > SpaceX should create a simple 'catch' the rocket game. Play
| in browser style. Just for kicks and marketing.
|
| They did: https://starshipthegame.spacex.com/
| CodeWriter23 wrote:
| I succeeded with a High Score of -287!
| KORraN wrote:
| This one is not from SpaceX, but gives way more fun:
| https://mechazilla.io/
| HPsquared wrote:
| That's great, really shows how they are "threading a
| needle" on the control side of things.
| tails4e wrote:
| Felt special witnessing history, was delighted my kids and
| their friends all were glued to the TV for it also.
| dtquad wrote:
| MIMO and nonlinear control theories are probably some of the
| hardest topics in all of engineering. SpaceX control system
| also has to compensate for the fuel moving inside their rockets
| so the control algorithms probably involve some kind of fast
| numerical fluid simulation.
|
| Another interesting thing SpaceX is doing is to use consumer-
| grade chips in triple redundancy configurations instead of
| using $100,000+ radiation-hardened aerospace/defense grade
| chips.
| autonomousErwin wrote:
| I always thought the liquid sloshing would be one of the
| hardest to simulate (considering how chaotic fluid mechanics
| is). Interestingly, I think this caused the 2nd Falcon launch
| to fail (the LOX sloshing).
| JorgeGT wrote:
| It is difficult, but there are modeling approaches that
| work, such as VoF
| (https://en.wikipedia.org/wiki/Volume_of_fluid_method).
| Basically, in addition to velocity, pressure, temperature,
| etc., you store an additional scalar in each cell of your
| computational mesh representing the liquid's volume
| fraction. Then, you solve an additional equation to
| transport that scalar.
| s1291 wrote:
| Solving the Navier-Stokes equations numerically in 3D is
| very time-consuming, even on HPC clusters, not to mention
| the additional modeling required for multiphase flows.
| Your answer implies that the solutions are obtained
| almost instantaneously, which is not the case.
| nothercastle wrote:
| They probably pre solved a bunch of scenarios and
| interpolate between them known solutions
| j_maffe wrote:
| That usually doesn't work for chaotic systems.
| KeplerBoy wrote:
| Maybe the tank is just not a large hollow structure but
| contains fins/compartments/whatever to restrict the
| sloshing motion and it's not that big a contribution to
| the overall motion.
|
| If it's no stronger than a sudden wind gust, it's just
| something the controller has to be able to take care of
| without a heads-up.
| TowerTall wrote:
| That is how they build the tank in Formula One Racing
| (and probably many other race cars, I guess)
| kaonwarb wrote:
| These are indeed part of the solution and are known as
| baffles. They have risks of their own, e.g.:
| https://wccftech.com/baffling-baffles-musk-explains-why-
| spac...
| nuancebydefault wrote:
| In the first spacex rocket Musk thought that it was a
| good idea to not install baffles. He learned from
| experience that they are indeed needed.
| m4rtink wrote:
| I remember a very similar anecdote about Von Braun & the
| early Juno/Jupiter rockets - with someone pointing out
| issues with sloshing on a press conference & Von Braun
| brushing it off as insignificant.
|
| Then the next launch crashed due to slosh induced
| oscillation - and the one rocket after that had anti-
| slosh baffles. ;-)
| vocram wrote:
| That's how tanks in race cars are made. Another solution
| is fill the tank with some kind of sponge-like material.
| m4rtink wrote:
| That would be far too heavy in this case. :)
| 486sx33 wrote:
| Sometimes... the baffles break off, and then become
| surfboard projectiles inside the tank.
|
| More fluid dynamics
| krisoft wrote:
| I think the reason these kind of simulations are fast
| enough is because they are very coarse and approximate.
| Don't think of asking how exactly the foam swirls around
| the individual longerons, more like a very rough
| estimation of which side of the tank the liquid is
| slumped to. Remember it doesn't have to be "exact" just
| close enough to be useful.
|
| By their very nature model predictive controllers operate
| in a world where not everything is perfectly modelled.
| Engineers do their best and whatever is left is the
| "error" the controller is trying to deal with.
| Log_out_ wrote:
| Or you compute variations ahead of time and do a
| situation based lookup, hoing through loops if a
| situation ressembles another one.
| keepamovin wrote:
| Maybe they don't need to model the fluid dynamics, they
| just need to detect the mass movement / acceleration
| forces caused by it, and use those sensor inputs to
| inform a picture that's fed into their correction
| thursting.
|
| Sort of like how you can balance a few pitchers of beer
| on a tray in your hand by remaining aware of the weight,
| even when people remove one! hahaha :)
| m4rtink wrote:
| Still if there indeed is "free" mass moving about, you
| need to make sure your control inputs don't make it slosh
| harder, so you compensate for that, so it sloshes even
| harder, etc - basically avoiding oscilation. :)
| keepamovin wrote:
| Yeah..ah, control theory. Heh :)
| jjk166 wrote:
| They don't need to solve the Navier-Stokes equations,
| they don't care how the fluid is actually behaving, they
| just need to approximate how the mass is moving within a
| margin of error that the control system can handle.
| WalterBright wrote:
| If the computation is too difficult, another approach is
| build a test stand and try methods until it works.
|
| Which is why we use wind tunnels, for example.
| JorgeGT wrote:
| Oh no, apologies if that was the impression I gave!! I
| actually perform CFD simulations in HPC clusters, and in
| fact I'm an admin of the small cluster at my research
| institute =)
|
| These are indeed heavy computations. What I meant is that
| VoF is one _additional_ equation to be solved besides the
| N-S equations (either filtered as in LES or Reynolds-
| averaged as in RANS), the energy equation, your
| turbulence model equations, and so on. Certainly, not
| instantaneous at all, but simply an additional "simple"
| model that we can hook into our current way of doing CFD.
|
| So, my point was, sloshing is a problem that we know how
| to simulate, although certainly you need HPC resources.
| Though, looking at those 100k NVIDIA H100 Elon has, I
| guess they have them! :P
| edm0nd wrote:
| I'm curious, how long time wise do these type of "heavy
| computations" take on clusters of HPCs?
| JorgeGT wrote:
| It really depends on the problem to be solved (domain
| size, complexity of physical phenomena such as turbulence
| model, heat transfer, acoustics, multiphase flows,
| combustion, etc., number of time steps required...). In
| our case we perform for instance simulations of
| turbomachinery acoustics that can take 3-4 weeks running
| in a few hundreds of CPU cores, combustion acoustics
| simulations that can take a week or two running in 1k-2k
| cores...
| knewter wrote:
| what if you had 100k H100s
| JorgeGT wrote:
| In reality few codes are capable of effectively
| parallelizing to so many computing processes. But, how
| cool would it be?
| swader999 wrote:
| Wouldn't it burn most of the fuel to mitigate the effect?
| dtquad wrote:
| I think some Kerbel Space Program players have attempted to
| approximate the liquid sloshing as an inverted single or
| double pendulum problem inside the rocket that the control
| algorithm has to take into consideration in addition to the
| primary control of the rocket.
| sobellian wrote:
| At least for the retro-propulsive landing burn, I think the
| modeling problem is probably aided by the high G-forces
| that must keep the fuel very close to the bottom of the
| tank. Even before re-light the booster is falling near
| terminal velocity (I think?), so the fuel is likely sitting
| at the bottom.
|
| I think it's a huge problem when re-lighting the engines in
| orbit, though.
| chasd00 wrote:
| Iirc cold gas thrusters are used before ignition to
| provide some acceleration to force the fuel to the bottom
| of the tank.
| baq wrote:
| The technical term for that is 'ullage'.
|
| See also: https://en.wikipedia.org/wiki/Ullage_motor
| m4rtink wrote:
| Also IIRC the massive main tanks in Super Heavy should be
| basically empty at landing & the landings propelants come
| from a set of small header tabks that are near the
| central axis of the vehicle & arr completely full. This
| should reduce or even fully remove sloshing issues at
| landing time.
| dmitshur wrote:
| Has it been considered to spin the fuel via some centrifuge
| mechanism as a way to remove sloshing from the equation, or
| is that more complex/expensive/error-prone than just
| predicting it via simulation?
| m4rtink wrote:
| I'm thinking we will eventually end up with "active fuel
| management" techniques like this for in space vehicles.
|
| Bug tanks make sense there & they might not be always
| full. So I can imagine all kind of interesting ways you
| can work with the fuel in zero go to avoid not only slosh
| but also the need for ullage thrusters. Eq. some
| programmable nozzles using in-tank gas to nudge liquid
| fuel blobs to move in the right direction. Or even some
| nets or bags that herd in the fuel in the middle of the
| tank + prevent it from directly touching the side,
| reducing boil-off or refrigeration requirements. :)
| phkahler wrote:
| Maybe they just use pressure sensors to tell where the
| fluid is within the tank.
|
| Even a real-time simulation should have some measurements
| to self correct to some degree. Otherwise it'll diverge.
| macinjosh wrote:
| There wouldn't be a whole lot of fuel left by the time it's
| back to land so likely an irrelevant factor.
| bob1029 wrote:
| https://en.wikipedia.org/wiki/Model_predictive_control
|
| http://cse.lab.imtlucca.it/~bemporad/publications/papers/ecc.
| ..
| sidewndr46 wrote:
| how much liquid fuel is present when it lands? I assumed all
| the clouds it was giving off was it dumping fuel to make sure
| it was empty on landing
| sephamorr wrote:
| Less than 5% of a full load. Any extra fuel you brought to
| the edge of space and back is lost performance, so
| substantial efforts are made to minimize this lost mass
| fraction.
| jccooper wrote:
| That's probably venting of excess pressurants and/or an
| engine purge.
| arijo wrote:
| I never thought of using fluid dynamics in the rocket
| stabilization algorithm--maybe it's something that could be
| useful to prevent many of the accidents involving liquid-
| transport trucks
| alexpotato wrote:
| Reminds me of the early days of Google File System.
|
| They used trios of regular consumer grade disks/servers etc
| as a cluster and it looked like a single node.
|
| They had to replace a LOT of hardware but this was still
| cheaper than big iron industrial grades servers.
| moffkalast wrote:
| Interestingly cheap redundancy is also how life does things
| for the most part. Most biological organisms just replicate
| a lot to guarantee success, so it's clearly a good strategy
| and an efficient use of energy.
| szundi wrote:
| Efficient as in evolution or in business: you just need
| to be more efficient than most of the peers
| arijo wrote:
| > Another interesting thing SpaceX is doing is to use
| consumer-grade chips in triple redundancy configurations
| instead of using $100,000+ radiation-hardened
| aerospace/defense grade chips.
|
| This has been known in the high availability and safety
| systems industry for a while and a good book to learn these
| reliability engineering techniques is "Reliability Evaluation
| of Engineering Systems".
|
| The book is available on amazon: https://a.co/d/1nH824K
| wildzzz wrote:
| One downside of using non-rad hard parts is degradation
| from TID (gamma) and latch up effects. You can have chips
| monitoring other chips to reset whenever they latch up but
| TID is mostly permanent. The good thing is that TID in LEO,
| where SpaceX mostly operates, is relatively lower than GEO
| so they can get by with mostly commercial parts. It's not
| like the big defense contractors haven't figured out the
| same thing, they do fly stuff using commercial parts as
| well, they are just slower to adopt the same culture.
| SpaceX and the companies that built components using
| commercial parts are building the new-space industry.
| christophilus wrote:
| Could you surround your components with gamma-shielding
| materials and get away with off-the-shelf parts deeper in
| space?
| gafferongames wrote:
| "To block gamma rays completely, you need about 13.8 feet
| of water, 6.6 feet of concrete, or about 1.3 feet of
| lead."
|
| https://www.epa.gov/radiation/radiation-
| basics#:~:text=Gamma....
| arijo wrote:
| You don't need to block gamma radiation completely to
| increase the electronics reliability :)
|
| Maybe you could improve the system availability
| considerably by a bit of gamma radiation protection
| combined with some more parallelism of the components ..
| adastra22 wrote:
| Usually partial blockage is worse, because you end up
| with a spray of secondary particles instead of a single
| ray.
| arijo wrote:
| Makes intuitive sense, thanks for the insight.
|
| A second layer blockage for the secondary particles
| wouldn't have to be as dense or am I missing important
| physics?
|
| (I guess a lot of gamma radiation would still reach this
| second layer so please ignore my question :)
| adastra22 wrote:
| Keep adding layers until you get to 1.3 feet of lead and
| it'll work.
| arijo wrote:
| haha thanks for the correction - I was under the Turtles
| All the Way Down mindset :)
| numpad0 wrote:
| Isn't that more like how you make bombs than armors more
| effective - with backside spalling and secondary
| fragmentations?
| exe34 wrote:
| can you block a hemisphere? the other 2pi steradians are
| shielded by the earth...
| m4rtink wrote:
| Maybe the secondaries could be blocked by
| different/lighter materials ? Basically a Whipple Shield
| for radiation. :)
| adastra22 wrote:
| Stopping power is basically correlated with mass.
| quailfarmer wrote:
| This may be true for high energy particles, but the
| majority of TID damage is done by higher flux lower
| energy, for which shielding is often viable!
| adastra22 wrote:
| The point is that shielding turns a single high energy
| particle that would otherwise strike and probably destroy
| a single transistor, into a veritable spray of lower
| energy particles causing bit flips or worse all over the
| circuit. This spray of particles can be stopped... with
| 1.3 feet of lead shielding.
| christophilus wrote:
| A box with 1.3' walls seems doable, actually, depending
| on how small the chips are. Might still be cheaper and
| more effective than specialized chips. But I know
| nothing, so am probably wrong.
| xmprt wrote:
| Lead is extremely dense so carry 1.3' walls of lead is
| probably more expensive than just having more redundancy
| or using better quality chips.
| thelittleone wrote:
| If the only thing that effectively shields these
| processors from radiation is lead, concrete etc (per
| earlier comments), what design changes / quality
| improvements can compensate?
| MetaWhirledPeas wrote:
| Does liquid fuel protect as well as water? Suspend the
| computers in the center of the fuel tank.
| jazzyjackson wrote:
| I think the trouble is such a cube would weigh 12,400
| pounds (a sphere maybe more reasonable at 6,510lb -
| without any room for electronics inside)
|
| https://www.wolframalpha.com/input?i=+lead+cube+with+side
| +le...
| paledot wrote:
| Hah, beat me to the nerd snipe. Moreover, that sphere
| would cost $10k to make and, at a launch price of
| $1500/kg, cost $4.5 million to launch into orbit.
| bboygravity wrote:
| The aim for the launch price of the entire rocket is to
| be around 5 million (once it's fully re-usable and in
| production). Basically the price of fuel and maintenance.
|
| So something might be off with your assumption of 1500
| usd / kg.
| m4rtink wrote:
| IIRC the CPUs are much less susceptible to damage when
| powered-off ? So have a bunch of them in cold standby or
| even as additional pluggable modules on missions with
| humans on board & swap to good ones when needed? :)
| SmellTheGlove wrote:
| How long until they can build that massive box, stage it
| in orbit, and pick it up/put it down as needed?
|
| I can't decide if I'm joking or not.
| piyh wrote:
| More water in orbit sounds like a good idea to me
| persnickety wrote:
| Can it even be blocked completely? Every layer of
| material geometrically reduces the proportion of rays
| going through. Or am I wrong about that?
| Filligree wrote:
| No, that's correct. Of course there's still some level of
| reduction beyond which the gamma rays don't matter, but
| where you want to place it is somewhat arbitrary.
| jiggawatts wrote:
| Just put the electronics in the middle of the header
| tank.
| jacobn wrote:
| Would they need to be blocked completely? Maybe a much
| thinner shielding would still produce a significant
| benefit?
|
| (Though likely not of course ;)
| mttch wrote:
| High energy gammas have a relatively low cross section,
| most are going to pass right through the chip. If you add
| a too little shielding, or don't layer shielding
| appropriately you are going to stop more gammas but
| produce lower energy x-rays from the shielding, which
| have a higher cross section, potentially increasing your
| chip dose.
| orbisvicis wrote:
| Would it be possible to create a "skip" EM shield that
| does the opposite - increasing the energy of the gamma
| rays thereby reducing the likelihood of stopping them?
| nine_k wrote:
| No idea how. Energies of most chemical bonds / electrons
| around atoms are not very high, not sufficient to emit
| proper gamma rays AFAICT. High-energy gamma rays are
| produced in nuclear reactions. While "clean" nuclear
| reactions that emit only gamma rays and not neutrons do
| exist, they are very high-energy and thus hard to
| initiate, and I don't think it would be easy to capture
| the energy of incoming gamma efficiently enough.
| quailfarmer wrote:
| Yes, you can attenuate TID effects with reasonably thin
| aluminum shielding
| wojciii wrote:
| I would wish you would use proper units. ;-)
|
| But would using redundant systems separated in space
| connected with each other not offset the chance that they
| all would be affected at the same time? This is actually
| not rocket science .. just hard engineering and
| hardware/software design for redundant systems which is
| also usable on the ground.
| WalterBright wrote:
| In reading Musk's biography,
|
| "Hollman also found that creativity got him a long way.
| He discovered, for example, that changing the seals on
| some readily available car wash valves made them good
| enough to be used with rocket fuel."
|
| "Elon Musk" by Vance pg 123
| MPSimmons wrote:
| There's a Lowes across the street from 1 Rocket Rd in
| Hawthorne.
|
| I doubt any Lowes parts made it to space, but you _know_
| some went into test articles
| kamaal wrote:
| I have seen some people who decide to keep moving forward
| with whatever they have at the time. Sure what they
| produce is way less than perfect, but what they produce
| is way ahead of what everybody else is doing.
|
| Perhaps the key is to be relentless, and resourceful.
| seabass-labrax wrote:
| Considering the political views of Elon Musk, it might be
| worth noting that his biographer is not the same Vance
| who is currently running for election as vice-president
| of the USA!
| WalterBright wrote:
| Aviation pioneered the use of redundancy in order to
| survive failures.
|
| The Fukushima and Deepwater Horizon disasters show that
| this knowledge has not penetrated other industries.
| michaelt wrote:
| Plenty of industries know about redundancy.
|
| But it turns out, it doesn't matter how many redundant
| backup diesel generators you've got if a 45-foot wave
| comes along and they're _all_ left underwater.
| eecc wrote:
| ... and you put all of them in the basement :/
| nmca wrote:
| Thank you very much for the reference!
| arijo wrote:
| You're welcome :)
| m4rtink wrote:
| From an article for this I remember one more interesting
| side effects of this approach - the flight computer ends up
| as a generic x86/ARM board that the engineers can just have
| on their desk during development. Previously the dev boards
| would use the same rad hard chips and would be as expensive
| and scarse as flight hardware, resulting in much harder
| development & engineers having much less experience with
| the real hardware.
| prox wrote:
| Just as a note, Space Engineers has a mod that accounts for
| fuel in the tanks and also various orbital mods. If one feels
| inclined to try it for themselves ;)
| serf wrote:
| as someone who absolutely loves SE -- please don't.
|
| the orbital and planetary mechanics kind of suck. They're
| meant to provide a decent 'arcade realism' for the sake of
| player/player interactions and pvp/pve.
|
| if you want to experience fuel slosh/weight during a
| vertical ascent/descent go with kerbal. It models a lot of
| that stuff _without_ mods -- and mods can make the model
| even more accurate.
| wildzzz wrote:
| I spent 2 semesters covering controls and I barely felt like
| I learned anything.
| WalterBright wrote:
| Reliability is not based on a system that cannot fail. It is
| based on a system that can survive failure.
| szundi wrote:
| ... or cannot fail
| mrdoops wrote:
| The canonical paper on handling software failures:
| https://erlang.org/download/armstrong_thesis_2003.pdf
| WalterBright wrote:
| There's much more to it than the programming language.
|
| Algorithms can be faulty as well.
| mlyle wrote:
| > There's much more to it than the programming language.
|
| Which was never claimed.
|
| That paper is a little bit about Erlang and a whole lot
| about OTP and other methodology and design technique.
|
| It is still, very much "the paper" for distributed
| systems, though its applicability to this particular
| problem is limited.
| e_y_ wrote:
| A system (whole) that can survive the failure of (some of
| the) individual parts. Up to a limit.
| mlsu wrote:
| I know MPC takes a LOT of compute power. It's not like a
| finely tuned PID loop or even a cascade of PID loops,
| computationally.
|
| Does anyone know (or have educated speculation on) what kind
| of hardware is running these algorithms? Like, do they have a
| linux machine that's running the control loops? Are we
| talking megabytes, gigabytes of SRAM?
|
| I would think no -- you would definitely need hard real time
| for something like this. But my only experience with real
| time systems is in tiny MCUs with kb of SRAM. That's
| definitely too small for a controller like this.
|
| Really curious about the nuts and bolts of this.
| mlyle wrote:
| MPC doesn't need to take a ton of compute power. It all
| comes down to how sophisticated the underlying model is.
| You can have a MPC with 20 variables and run it at multiple
| kilohertz on a tiny microcontroller.
|
| When you build something like this, you're torn between
| having a big model that represents _everything_ and a
| smaller model that is easier to validate and reason about.
| Based on simulation, you might go for a smaller model that
| "knows" to stay away from operating areas where hidden
| variables (like really complicated tank slosh) invalidate
| the small model.
|
| I doubt the actual control loop is too much processing, but
| it's certainly possible to build controllers with SDRAM,
| millions of variables of state, and hard realtime
| processing, though I wouldn't build it on top of preempt-
| rt. ;)
| bgnn wrote:
| It would be a real time OS running it for sure. Which one I
| don't know.
| quailfarmer wrote:
| They have publicly discussed using Linux with RT kernel!
| erikerikson wrote:
| I have been told by people who worked on them that you get
| radiation hardened aerospace/defence grade chips by backing
| off the clock speed about 20% to give signal stabilization
| slightly longer time. I can understand the population being
| confused about this but industry being confused seems to have
| more to do with regulatory capture and beaurocratic moats
| which SpaceX does seem to be bypassing.
| mensetmanusman wrote:
| You also have to add massive amounts (relatively) of static
| sink by approaches like 'silicon on insulator' to prevent
| energetic electrons from hopping into the transistor layer.
| m4rtink wrote:
| I'm sure there are many hardening processes - from the
| modified COTS parts, all the way to presumably much more
| expensive custom substrates like:
| https://en.wikipedia.org/wiki/Silicon_on_sapphire
| macawfish wrote:
| People don't realize how powerful applied math (especially in
| the areas you've mentioned) has become. Same tools can be
| applied to people in the ad tech/social media.
| schiffern wrote:
| >probably involve some kind of fast numerical fluid
| simulation
|
| Sometimes even a simple approach can work. On Apollo they
| developed (at the time cutting-edge) passive RC filter
| networks, to avoid the control system "exciting" the rocket
| at frequencies of the slosh/bend/torsion modes.
|
| https://ntrs.nasa.gov/api/citations/19700023342/downloads/19.
| .. (search for "slosh" or "shaping network")
| gcanyon wrote:
| > control system also has to compensate for the fuel moving
| inside their rockets
|
| My stepfather worked as a programmer on the Apollo program,
| and the thing he always talked about as his biggest
| accomplishment was working on the "slosh problem" -- so yeah,
| props to the SpaceX team for managing that landing. And props
| to my stepdad for managing it on hardware that was... a
| billion times less capable? :-)
| kbmr wrote:
| Did he get a chance to see any of the recent SpaceX
| accomplishments?
| gcanyon wrote:
| Nope, died fifteen years ago.
| falconertc wrote:
| I might be misremembering but I think slosh was the failure
| cause for one of the three failed Falcon 1 flights. It was
| number 11 out of a pre-flight list of top 10 most likely
| failure scenarios. Definitely a difficult problem.
| 3abiton wrote:
| > MIMO and nonlinear control theories are probably some of
| the hardest topics in all of engineering.
|
| I am curious but clueless about these problems, can you
| expand more?
| mataslauzadis wrote:
| Google is a good place to start.
| https://en.wikibooks.org/wiki/Control_Systems/MIMO_Systems
| restalis wrote:
| _" instead of using $100,000+ radiation-hardened
| aerospace/defense grade chips"_
|
| Well, that makes perfect sense considering that both the
| spaceport infrastructure, and the booster need to do their
| calculation on the ground level instead of the highly
| radiated environment that is space. However, for the rockets
| themselves, which happen to reach that harsh environment,
| they may use more resilient and expensive hardware in the
| future, after passing over the current "let it splash in the
| Indian Ocean" development and testing phases.
| debit-freak wrote:
| > SpaceX control system also has to compensate for the fuel
| moving inside their rockets so the control algorithms
| probably involve some kind of fast numerical fluid
| simulation.
|
| Surely this isn't necessary with a small enough sensor
| granularity or whatever the terminology is. You can have very
| dumb software if it reacts quickly enough to changes in
| perception.
| noahbp wrote:
| I'm not an engineer, but is there a reason why they can't
| french press (sans filter) the fuel toward the bottom of the
| tank as it empties?
| e_y_ wrote:
| (Not an engineer either) My understanding is that it's been
| done before on smaller scales but having a giant piston in
| the tank requires a good seal, railings to keep it
| straight, and overall way too much mass and rigidity.
| Consider that the tank walls are only a few millimeters
| thick.
|
| Instead, it's more common to use gasses injected at the top
| of the tank to push the liquid to the bottom. Falcon 9 uses
| helium. Starship uses
| https://en.wikipedia.org/wiki/Autogenous_pressurization as
| well as small header tanks for the landing propellants.
| jatins wrote:
| timestamp for "catch" is around 40:00 for those curious
| blackeyeblitzar wrote:
| When Musk first proposed this, I thought he was crazy. It
| seemed like something a school boy would draw up. Now I think
| this will become routine and forgettable after a few more
| successes. Is there a word for that - something out of fiction
| becoming mundane?
| api wrote:
| I thought it was plausible given the accuracy of F9 landings,
| though I still wonder how it will work at scale if one
| failure destroys the landing site. That could ruin the cost
| benefits.
|
| Where his vision hit a lot of speed bumps is second stage
| reusability. Starship is a beautiful second stage to throw in
| the ocean. They'll probably get it landing but the heat tiles
| will require a lot of refurbishment between flights. They're
| going to have to figure something else out.
| DiggyJohnson wrote:
| I really don't think it will ruin the cost benefit as much
| as you suggest, especially when they have multiple sites
| and multiple locations. It wound be catastrophic, but they
| are presumably building Tower like the rest of their
| hardware, and every time they launch it represents a $100M
| saving compared to the competition.
| ericcumbee wrote:
| It took months to more than a year to repair shuttle's
| heatshield in some cases. SpaceX replaced the entirety of
| the heatshield with a new design and a new ablative
| underlayment in a matter of weeks. I suspect they will be
| able to do it even quicker with design and process
| improvements. Small scale repairs of the heatshield between
| flights probably wont be all that big of a deal.
| dralley wrote:
| The fact that Starship is unmanned probably helps
| expedite the change process quite a bit vs. the manned
| Space Shuttle. If you want to "just try something" the
| most you can lose is money, and not create a national
| political scandal.
| ericcumbee wrote:
| I think the problem with shuttle was more fundamental.
| most of the tiles for Shuttle were custom cut to fit
| exactly one spot on one orbiter. I've read that NASA
| replaced about 75 tiles per mission, and that 2/3rds of
| the cost of refurbishing a shuttle after flight was the
| TPS. so the cost of trying something out was massive.
| cryptonector wrote:
| I'm expecting that SpaceX will have lots of towers, not
| just one (currently) or 3 or 4 (under way). It won't just
| be for redundancy. The duty cycle of a tower might simply
| not allow for the cadence that SpaceX wants to maintain.
| With Falcon 9 they currently have a 3x weekly launch
| cadence (which is unbelievable enough). With full
| reusability they might be able to get to daily and better
| cadence, so if the duty cycle of one tower does not support
| that (I assume right now it does not) then they'll need
| more towers.
| gibolt wrote:
| A flight to Mars is currently going to require 10 tanker
| flights just to get enough fuel into orbit for 1 Starship
| trip. Containing liquid fuel for long in orbit will not
| be easy.
|
| This likely means they are targeting 10 flights in a day
| at least. They've mentioned 1000 trips to Mars during one
| transit window, which means ~10000 Earth launches within
| 3 months, or >100 per day.
| edm0nd wrote:
| iirc they plan on making multiple launch sites so one
| getting damaged wont grind operations to a halt.
| ninetyninenine wrote:
| This happened with LLMs in a big way. Basically humanity
| surpassed some kind of AI milestone and we zoomed past the
| turing test in a big way. But thanks to social media everyone
| is sort of rolling their eyes at it.
| restalis wrote:
| _" When Musk first proposed this, I thought he was crazy."_
|
| _" Is there a word for that - something out of fiction
| becoming mundane?"_
|
| Musking?
| shatnersbassoon wrote:
| 2 related expressions: 1. Creeping Determinism - the idea
| that even magical leaps forward were somehow inevitable and
| were anticipated. 2. Nihil Admirari - the idea that wisdom is
| anticipating every possible thing that could happen,
| therefore a wise person would never be surprised.
|
| But I lump both these together as the *"Wiseass Movable
| Feast"*
| drexlspivey wrote:
| The booster was falling at 4500 Km/h 30 seconds before the
| catch with 2-3% fuel left. How is that amount of fuel remotely
| enough to stop the downward momentum?
| stetrain wrote:
| Because the rocket weighs a small fraction of what it did at
| launch, specifically because it only has 2-3% fuel left.
|
| Fuel is the vast majority of the vehicle weight at launch,
| kind of like an empty vs full can of soda.
| justin66 wrote:
| The atmosphere does its bit to slow down the booster as
| well. It'd be interesting to see a plot of the power output
| over time on reentry but I've always assumed the motors
| aren't doing a lot of work other than keeping the booster
| stable, until the very end.
| stetrain wrote:
| Yes, for most of the booster return it's 'gliding' with
| the rocket engines completely shut down.
|
| They ignite a subset of engines just a few seconds before
| landing for the final slowdown and maneuvering.
|
| Edit: here is a video from further away that shows the
| rocket gliding in under control of the grid fins before
| the engines light and execute the final landing maneuver:
|
| https://x.com/shaunmmaguire/status/1845444890764644694
| justin66 wrote:
| Super heavy probably makes certain aspects (unrelated to
| the tower catching the booster) of landing much easier,
| by virtue of its greater mass. Timing with the Falcon 9
| was always essential, because the minimum thrust (with
| one motor, throttled all the way back) of one of the
| engines was enough that if you left the motor running,
| the booster would start to rise. Time the beginning of
| the final burn incorrectly and you had a real problem,
| with the booster either crashing or rising at the end
| and... then crashing, but with Super Heavy, it might
| simply be a matter of having to compute a slightly
| different sequence for shutting off the engines.
|
| They sure made it _look_ easy...
| HarHarVeryFunny wrote:
| Super Heavy is easier to control on landing because it's
| using 3 engines so has better directional control, and it
| can throttle those engines down into a sustained hover,
| which is what it does before being "caught" by the arms.
|
| Surprising to see this work first time though - I don't
| recall them doing any hover and lateral movement tests,
| but I assume they must have done.
|
| What's also wild is that the booster isn't being
| caught/supported by those giant grid fins, but rather by
| small lifting pins just below them, and seems to only
| have two of these (one on either side), so it also has to
| get it's rotational position right so those pins engage
| with (are supported by) the arms.
| nordsieck wrote:
| > Yes, for most of the booster return it's 'gliding' with
| the rocket engines completely shut down.
|
| Watching the video, it looked like the bottom of the
| rocket was glowing hot, but the engines were cool. I
| imagine that means they were probably running some amount
| of methane through the engine bells to cool them.
| HarHarVeryFunny wrote:
| Yeah, but even without fuel the booster weighs 200 tons.
| It's pretty wild to have 200 tons of steel incoming at
| supersonic speed, then nailing a gentle pinpoint landing
| like that !
| chasd00 wrote:
| Yeah if the engines didn't light and it hit the launch
| facility that whole place would be a crater. The whole
| thing was shocking to me but how fast it was coming down
| was extra shocking haha. I wonder what deceleration
| forces were at play because when the engines lit the
| booster slowed down very fast.
| chedabob wrote:
| It weighs about 10% of what it did at liftoff, but half of
| the engines fire to slow it down.
|
| Also I don't think the telemetry on the feed is that
| accurate, so with all of the atmospheric braking, it was
| probably going a bit slower than the 1200km/h at engine
| reignition.
| magicalhippo wrote:
| First off, the booster was going about 1250 km/h when it
| started its landing burn, it relied purely on drag to get it
| slowed down to that speed.
|
| Going by the telemetry of the seconds before the landing burn
| and noting the speed vs time, it seems drag was around 40
| m/s^2 when it was going at around 3000 km/h. Since drag
| depends on velocity squared though, it had reduced to just
| above 10 m/s^2 just before the engines lit at 1250 km/h, and
| so would quickly become negligible once the engines lit.
|
| Going by Wikipedia, the Super Heavy[1] has 3400000 kg of fuel
| at launch, so 3% of that is about 102000 kg. For the landing
| burn, it used 13 Raptor v3 engines[2] to scrub speed. Each
| Raptor flows about 650 kg/s max, so 3% fuel is enough for
| about 12 seconds for the 13 engines.
|
| The empty mass of the Super Heavy is about 275000 kg, so
| about 377000 kg before the landing burn with 3% fuel.
|
| Using the sea-level vs vacuum performance of the Raptor v2
| engines, one can estimate that each Raptor v3 produces about
| 2.45 NM of force at sea-level. So 13 of them would produce
| about 31.85 MN of force.
|
| Using Newton's second law, F=ma, this gives an initial
| deceleration of about 84 m/s^2 and about 104 m/s^2 when
| empty. If we do a rough spreadsheet integration, we get that
| a burn of roughly 4 seconds is needed to scrub the speed
| assuming no other forces.
|
| Now, comparing this with reality, the full 13 engines were
| lit for a little over 5 seconds.
|
| In my simplified calculations I was assuming full throttle
| the whole way, which obviously isn't realistic, and I also
| assumed 3% fuel. So over all I think that's a pretty decent
| estimation.
|
| [1]: https://en.wikipedia.org/wiki/SpaceX_Super_Heavy#Engines
|
| [2]: https://en.wikipedia.org/wiki/SpaceX_Raptor
| rsync wrote:
| "... Super Heavy[1] has 3400000 kg of fuel at launch ..."
|
| So, 34M kg of fuel has to be burned (in this booster alone)
| to facilitate a flight ... and I see that the propellant is
| CH4 / LOX[1].
|
| Burning methane is much, much better than simply releasing
| methane but the release becomes CO2 instead ...
|
| What is the back-of-the-envelope conversion of 34M kg CH4
| vs., for instance, 34M kg of kerosene/JP ?
|
| [1]
| https://en.wikipedia.org/wiki/SpaceX_Super_Heavy#Engines
| CrazyStat wrote:
| 3.4 million, not 34 million. And that includes the weight
| of the liquid oxygen, which is heavier than the methane.
| ylere wrote:
| Methane has 28% more energy per kg than kerosene and also
| produces slightly less CO2 (2.75kg CO2/kg burned vs 3.00
| for kerosene) when burned [1]. SpaceX uses a 78:22 LOX to
| CH4 ratio, so for 34M kg of fuel burned, 20.57M kg of CO2
| are produced (34x0.22x2.75).
|
| [1] https://www.engineeringtoolbox.com/co2-emission-
| fuels-d_1085... [2]
| https://x.com/elonmusk/status/1298426245991063554?lang=en
| aw1621107 wrote:
| Somewhat tangential, but as far as rocket fuels go energy
| per volume is also an important metric to consider. It's
| one of the (several) reasons hydrogen isn't quite as good
| for rockets in practice as it is in theory - while
| hydrogen has tons of energy per unit mass (120-142 MJ/kg
| for hydrogen vs. 50-55 MJ/kg for methane and 43.1-46.2
| MJ/kg), it has a far lower density (70.85 kg/m3 vs. 422.8
| kg/m3 for liquid methane and 820 kg/m3 for kerosene). As
| a result, you need quite a bit more tankage for a given
| amount of energy from hydrogen compared to what
| methane/kerosene requires.
|
| IIRC there's a tradeoff between efficiency and thrust as
| well. Heavier fuels aren't quite as energy-efficient, but
| it's easier for them to develop a lot of thrust, which is
| important for the initial stages of launch. If I'm
| remembering events described in _Ignition!_ correctly
| this led to "thrust density" being something that was
| optimized for - to the point that there were experiments
| with mixing mercury into the fuel!
|
| [0]: https://world-nuclear.org/information-library/facts-
| and-figu...
|
| [1]: https://en.wikipedia.org/wiki/Kerosene
| ylere wrote:
| Correction (can't edit the post anymore): As another
| commenter pointed out, the rocket can carry 3.4M kg of
| fuel, not 34M kg.
| Yacovlewis wrote:
| What kind of work do you do that you're able to understand
| this stuff? Genuinely curious. I'm way beyond my depth
| trying to follow
| r3d0c wrote:
| this is ap hs physics or uni 1st year physics
| Yacovlewis wrote:
| You can do a lot with basic physics if you understand it
| well
| magicalhippo wrote:
| Just a programmer, though been interested in physics
| since I was a teen and did take a bachelor degree in
| simulation (mainly physics).
|
| Long ago though so rusty, $dayjob doesn't involve any
| advanced math at all.
|
| edit: To expand, the "rough spreadsheet integration" was
| just the Euler method[1] assuming a constant
| acceleration. So v(t+dt) = v(t) + a *
| dt
|
| The acceleration comes from F=ma as mentioned, where F is
| the force of the engines (Newtons), m is the mass of the
| rocket (kg) and a is the acceleration (m/s^2). Solving
| for a we get a = F/m and we get v(t+dt)
| = v(t) + F/m(t) * dt
|
| To make things easy I assumed the weight of the rocket
| was constant at each timestep, but if we take dt to be
| small enough it's a decent enough approximation. For each
| timestep I also updated the mass using the estimated mass
| flow: m(t+dt) = m(t) - 650 * dt
|
| I started with m(0) = 377000 kg, v(0) = 1250 km/h = 347
| m/s, and a constant -31850000 N force from the engines.
|
| Using dt = 0.1 seconds, I got almost exactly 4 seconds
| until the velocity reached zero.
|
| [1]: https://en.wikipedia.org/wiki/Euler_method
| magicalhippo wrote:
| > 650 * dt
|
| That should of course be 13 * 650 * dt.
| nine_k wrote:
| Newton's laws of mechanics are high-school physics IIRC;
| my son studied them at 8th grade or so. They are really
| simple; an evening with Wikipedia or 3blue1brown or
| whatever floats your boat will let you get sufficient
| understanding, provided you're also comfortable with
| high-school math.
| martythemaniak wrote:
| That's excellent work, only nit is I think these were not
| the v3 raptors. I think they're just now starting
| production of those, so they still have a bunch of earlier
| ones they need to use up in these early test flights. This
| actually makes your calculation more accurate, as earlier
| versions will need a slightly longer burn time.
| magicalhippo wrote:
| Ah, good catch, I must have misread the Wikipedia page. I
| misread that they were included in the rocket in August.
| Reading the Raptor page more closely I also see that the
| 2.75 MN of the Raptor V3 are supposed to be at sea-level.
|
| Anyway, plugging in the Raptor V2 thrust numbers the
| approximation increases to 4.25 seconds. This is in line
| with the thrust I used for the V3 being ~8% higher than
| the V2 thrust figures.
| jjk166 wrote:
| Note that the energy of 3% of the propellant (~100 GJ) could
| theoretically get the empty booster (100,000 kg) to a little
| over 5000 km/h if properly applied.
| Torkel wrote:
| I thought the same, screamed out "ouch that doesn't look good!"
| right before the catch.
|
| The last part of the live stream they showed footage from a
| different angle and there it didn't look too bad though! For
| sure controlled.
|
| Scott Manley put out a tweet that they went down towards a non-
| tower position until they were at three engine controlled burn,
| and only then did the side shift.
| nh2 wrote:
| Timestamp of the different angle?
| Torkel wrote:
| https://youtu.be/eXsT2HT171o?si=gUmdFvU4l-9ZiWrv&t=4237
| brcmthrowaway wrote:
| Do the control algorithms use AI?
| arijo wrote:
| Actually this is a good question - there's a lot of control
| engineering research on Data-Driven Control Systems.
|
| Check Steve Brunton youtube channel, he is one of the leaders
| in this area:
| https://youtu.be/gb_C9LcjDSI?si=xUjqUZ9-0MIFohX6
| ThouYS wrote:
| If I had to bet, I would bet against it. Boston Dynamics for
| example, for the longest time, didn't use anything other than
| Model-Predictive Control. Only recently have they started
| using RL
| lutorm wrote:
| No. Way too hard to validate.
| shellfishgene wrote:
| The simulation they show at 21 min into the video is almost
| exactly like it happend in the end, to it seems it went
| perfectly as planned.
| pj_mukh wrote:
| I know the control algorithms are the mind-blowing part here
| but,
|
| does anyone have any literature about how the Rocket localized
| itself with respect to the chopstick arms? It must've been some
| combination of GPS and Radar pings to the arms?
|
| And then the onboard IMU to make sure it hits it straight.
| ThouYS wrote:
| super good question, especially with all the tilting
| involved, which would make visual servoing difficult. Maybe
| some form of beacons on the ground?
| cdash wrote:
| Could just be differential/rtk GPS. You can get incredible
| precision with that.
| shellfishgene wrote:
| From the control point of view, isn't this exactly the same
| as F9 landing on a pad, except the pad is virtual, floating
| in between the chopsticks and the ground? Or course one
| difference is that the approach needs to be from the correct
| direction.
| m4rtink wrote:
| I seems to remember some article mentioning the Falcon 9
| using radar (+ presumably other sensors) & even having a
| landing site map uploaded (mainly for the return to launch
| site scenarios) with prioritized exclusion zones in case of
| a landing failure.
| schiffern wrote:
| Hans Koenigsmann alluded to mapping during the CRS-16
| post-flight press conference.
|
| https://www.youtube.com/watch?v=tVSPCPoc8hs&t=373
| jessriedel wrote:
| A major difference is that F9 (landing on a wide flat pad)
| had a quite wide acceptable horizontal error, 10 meters or
| more, whereas I think this (landing between two chopsticks)
| needs like ~1 meter accuracy in the radial direction.
| varenc wrote:
| Great question! Could just be Real-Time Kinematic (RTK) GPS
| like someone mentioned. Essentially the landing arms know
| their position very precisely and they measure the tiny
| errors in GPS data, and send that correction data live to the
| rocket in real-time as it's landing. Once the rocket gets
| very very close it could also just be using vision systems to
| zero-in on exactly where the chopsticks are.
|
| To speculate more, they could also be using something like
| ultra-wide band positioning. This relies on the same time-of-
| flight principle as GPS but instead of using satellites in
| orbit to provide the precise time information you rely on
| various nearby ground stations. Would only be useful right at
| the final approach, the last couple hundred meters, but it's
| another way they could get very very precise position
| information. (fun fact: Ultra Wide band positioning is also
| how iPhones can locate AirTags with centimeter accuracy)
| pj_mukh wrote:
| ooooo Yea forgot about RTK GPS. I've always found them to
| be so brittle but that's because I'm in a city.
|
| In the wide open sky, I'm guessing it's pretty reliable.
|
| Vision systems would be pretty useless with the low
| visibility of the smoke and fire. So I thought maybe it was
| some kind of radar configuration.
|
| Anyways, I'd pay a lot of money to pick the brain of the
| GNC team here.
| psb217 wrote:
| Why bother with GPS or other "absolute" coordinate
| systems? Once the rocket's in close, all that matters is
| relative position and orientation of the rocket with
| respect to the landing apparatus. Eg, if you had many
| sensors in known locations on the rocket and many sensors
| in known locations on the landing apparatus, and you
| could measure relative positions between all pairs of
| these sensors, you could get extremely precise relative
| position/orientation information without beaming
| information to satellites or whatever.
| stetrain wrote:
| Here's a video from a farther vantage point that gives a better
| perspective on the landing process:
|
| https://x.com/shaunmmaguire/status/1845444890764644694
| gcanyon wrote:
| That's amazing footage, and you're right about the
| perspective: from the official feed the distances seem
| compressed compared to what we see in this footage.
| ralfd wrote:
| The little boy who was lifted on his dad's shoulders got me
| emotional.
| Faark wrote:
| Wow, those pressure waves! Didn't see them yet, on all the
| close up footage. Thx for posting
| jccooper wrote:
| There's also a very impressive sensor and actuator story.
| slashdave wrote:
| Yes, indeed. But I will add that the sheer size of the rocket
| helps in this regard. I think it is rather hard to appreciate
| the massive scale of the feat by watching videos.
| mrweasel wrote:
| A clip from some news program popped up on YouTube, just a two
| minutes clip of the catch, I was convinced that it was
| reversed. The fact that this is possible, that they made it
| work is nothing short of amazing.
| gibolt wrote:
| Prior launch landed 0.5cm away from the target location. This
| is equivalent to landing a 25 story building right on the
| foundation.
|
| Absolutely impressive accuracy and precision.
| Zealotux wrote:
| Uuuh the first stream on YouTube was Musk giving a speech, so I
| was waiting for the launch but turns out it was on another
| stream? So I just missed the whole thing, great.
| sourcecodeplz wrote:
| They don't do lives on youtube, those are scammers. it is
| always on x.com
| Zealotux wrote:
| Well it shows like SpaceX on mobile with 150k viewers, maybe
| YouTube could use some brain power to fix that.
| dotnet00 wrote:
| This has been going on for many years now, YouTube doesn't
| do anything about it.
| lupusreal wrote:
| Youtube is an incompetent organization. I've seen it take
| them nearly 48 hours to restore channels stolen by scammers
| to their rightful owners (all the while allowing the crypto
| scammers to continue streaming.)
| panick21_ wrote:
| Youtube simply doesn't care about their platform being used
| for scams. There are very simply very basic things they
| could do, but they simply don't.
| sgt wrote:
| They're quick to demonetize people though. Anything to
| make an extra buck.
| acheron wrote:
| Sorry, too busy selling ads.
| bearjaws wrote:
| Would be great if I could stream to my Chromecast or AppleTV
| from X without using airplay streaming my whole browser...
| panick21_ wrote:
| There were multiple streams on youtube who rebroadcast that
| you can use.
| jdminhbg wrote:
| There used to be a Twitter AppleTV app and I recently saw
| an X app for TV platforms has been brought back, but I
| don't know if the AppleTV version is out yet.
|
| Of course I'd rather they just stream to YouTube in 4K.
| thepasswordis wrote:
| Youtube has a terrible problem with scammers. I don't know why
| they don't do anything about this.
| diamondfist25 wrote:
| And yet all MSM channels are the first thing u see when u
| query certain topics and people.
|
| It's intentional
| hggigg wrote:
| There was an AI crypto scam channel. Musk is so scammy that it
| looked feasible and was shared widely by the looks.
| inemesitaffia wrote:
| https://twitter.com/i/broadcasts/1RDGlyognOgJL
|
| Here. Or try Space Affairs on YouTube
| mensetmanusman wrote:
| Those are deep fake crypto scams that YouTube does not pull
| down. My father was scammed by one for over $2000.
|
| The older we get, the likelihood that we get scammed approaches
| one. Be weary.
| belter wrote:
| Everyday Astronaut Stream: https://youtu.be/pIKI7y3DTXk
| ceejayoz wrote:
| That was craaaaaaaazy!
| sekai wrote:
| Magnificent, it's hard to image what we'll be able to do once
| these do roundtrips daily. For those are not aware, that booster
| is 71 m (233 ft) tall!
| paulryanrogers wrote:
| Improvements that make space flight more sustainable are
| welcome ... unless that means an order of magnitude more
| pollution in a less controllable form, like emissions. [Due to
| more frequent flights]
|
| Daily trips to space likely also mean more debris in space and
| falling to earth.
|
| I hope there is a balance that includes the lives of people
| near these sites and all of us sharing the same atmosphere.
| timeon wrote:
| I hope this is not going to be used for 'Earth point A ->
| Earth point B' travel.
| modeless wrote:
| SpaceX proposed it but I doubt there is any chance of this
| architecture ever achieving the airliner-level reliability
| needed for people to accept routine Earth-to-Earth
| passenger service. That's several levels beyond what you'd
| need to fly astronauts.
|
| Maybe a future architecture with more redundancy could get
| there someday.
| smoovb wrote:
| Proposed 7 years ago - go anywhere on earth in an hour:
| https://www.youtube.com/watch?v=2tf2KpCG2fM
| joko42 wrote:
| Humanity has reached a milestone.
| qwertox wrote:
| Congratulations to those working at SpaceX!
| delichon wrote:
| I would like to shake the hands of the steeley eyed rocket men
| and women who just landed a skyscraper with centimeter precision.
| Respect.
|
| This one's for you. Hit it Perry.
| https://www.youtube.com/watch?v=_VJlHWESyLI
| melodyogonna wrote:
| THEY REALLY CAUGHT IT!
| Yacovlewis wrote:
| Seems impossible honestly. Like the Jetsons
| gadders wrote:
| It still blows my mind how the landings are more exciting than
| the launches.
| bombcar wrote:
| I'm completely mind-blown that not only can they do this, but
| we get 1080p video for almost the whole time.
|
| What cameras do they have that can look at something 30 KM up
| in the air that well?
| throwaway48476 wrote:
| At one time they were using gopros.
| generuso wrote:
| Usually it is a small telescope on a nice motorized mount
| weighing a ton. NASA had several of those around Cape
| Canaveral [1].
|
| [1] https://www.youtube.com/watch?v=xig3sL_rRH8
| yonatan8070 wrote:
| The thing that impresses me even more is the kinds of cameras
| they mount on the rocket. How do they shield it from all the
| heat and debris with a material that's optically clear?
| ceejayoz wrote:
| They put it in places the heat and debris don't go.
| jjk166 wrote:
| Sapphire glass windows: they're good for up to 2000 C,
| mechanically strong and chemically resistant, and
| remarkably cheap.
| ars wrote:
| Sapphire is Aluminum Oxide. Transparent Aluminum
| basically.
|
| It's an amazing material that is not used as much as it
| should be.
| aksss wrote:
| As in life, when a person is on a road to nowhere, it's the
| homecoming that's sweet. The only thing more exciting than an
| Earth landing will be a moon or Martian landing. Or the in-
| orbit fuel consolidation docking, if only because it will be a
| huge milestone.
|
| https://open.spotify.com/track/7wFmJxJfGCN6DM5913y7pr?si=-Uo...
| cynicalpeace wrote:
| "Incredible!" in the voice of my 3 year old who just saw it :)
| ptek wrote:
| Very inspiring, glad I woke up to watch it. Congratulations to
| the SpaceX team. This is what competition looks like. It's funny
| how last decade SpaceX had to sue the government to get more
| launches.
| XorNot wrote:
| The FAA needs more funding at this point. They're not staffed
| for the rate of launch requests which commercial space has
| grown too.
| bombcar wrote:
| We're going to need a dedicated FSA (federal space agency) at
| this rate, which should do most of the heavy lifting (ha) for
| the FAA and just use them for NOTAMs and TFRs.
| mkoubaa wrote:
| What makes you think the issue is funding?
| mptest wrote:
| Oh idk maybe picking up just about any recent history book?
| ie, the goals and effects of austerity politics?
| systemvoltage wrote:
| Need to remove regulations instead and fast track SpaceX.
|
| Every fucking time we don't need to increase the size of the
| Government. It only gets bigger. Never smaller.
| dawnerd wrote:
| No, launching big heavy explosive things into space
| shouldn't have fewer regulations. That's insane to think
| they should be able to just do it without much oversight.
| tomschlick wrote:
| Sure the safety part of it is something that should be
| verified before launch. But when they are launching
| multiple of these things and the variables are all mostly
| the same you don't need to do the same analysis over and
| over again.
|
| A prime example is the environmental impact stuff. They
| have already done that multiple times. Nothing really
| changed. If it succeed and doesn't blow up the impact is
| X, if it blows up the impact is Y. Yet these approvals
| take weeks and months.
|
| There are also multiple agencies that put their foot
| down. Famously fish and wildlife was worried starship
| would crash in the water and hit a shark/whale. No
| seriously. https://youtu.be/kS8G5D9fg3g?t=21
|
| Then there is the story that at Vandenburg air base, they
| had to strap a seal to a board and play rocket noises
| through headphones to see if it was distressed. Keep in
| mind Vandenburg has been a military rocket launch site
| for decades. But only now when its SpaceX do these
| agencies put up road blocks.
| https://www.youtube.com/watch?v=3SvJP5wfN4k
| ceejayoz wrote:
| > Keep in mind Vandenburg has been a military rocket
| launch site for decades.
|
| Not one of which ever returned to base with a sonic boom.
|
| I assure you, the folks who tried to kill goats via
| mental powers and staring at them have required weirder
| tests than the seal.
| tacticalturtle wrote:
| Isn't this exactly what happened with Boeing, where the FAA
| delegated its authority, on the assumption that Boeing knew
| what it was doing?
| dmix wrote:
| Regulations probably are not going to fix the rot that's
| inside Boeing. It's like putting water in groundhog
| tunnels, clamp down on one area and it will pop up
| somewhere else.
|
| They need to die off and get replaced by better
| competition when they mess up. And their market
| centralization ground to a halt instead of encouraged by
| the gov because of jobs and total risk aversion.
| mensetmanusman wrote:
| Boeing is publicly funded though, which means crazy
| incentives take over that are out of whack.
| derektank wrote:
| If by the size of government you mean the budget, there
| have been multiple instances of the government shrinking.
| As a percent of GDP the 90s saw cuts to federal spending,
| the 2011 sequestration saw a drop in spending even in
| nominal terms, and obviously the end of WW2 saw a massive
| collapse in government spending and the end of multiple
| different programs
| chasd00 wrote:
| More money would make the situation worse. They need
| competent leadership. Everyone like to just say "add more
| money" because it means no actual operational change to the
| status quo.
| acd10j wrote:
| You are right they are already trying to slow SpaceX as
| much as possible. More people in their hands more people
| finding ways to decelerate SpaceX
| atrus wrote:
| Hardly, the FAA is handing permits out the instant the
| mandated waiting time is up. They couldn't go faster
| without a _literal_ act of congress.
| TrapLord_Rhodo wrote:
| It's not a mandated "Waiting time". It's the max amount
| of time that they have to respond. And they wait until
| the very last day.
| gamblor956 wrote:
| The FAA already has competent leadership and staff. They
| don't have the budget to handle the increasing number of
| tasks they have been given to manage.
|
| The FAA manages _more_ flights and space launch operations
| than it did in the 1980s, when it had a budget more than
| quadruple the size.
|
| To put it bluntly: you get what you pay for.
| nmca wrote:
| You get what you incentivise, not what you pay for.
| mensetmanusman wrote:
| Yeah in my area govt. officials can be incentivized to
| say no to prove they are doing the job. Adds massive
| amounts of delay.
| whimsicalism wrote:
| perhaps we need less thorough reviews
| whimsicalism wrote:
| Not sure why this is downvoted.
|
| Our risk-to-regulatory oversight cost benefit analysis
| seems _extremely off_ - we overregulate small things that
| do not have large-scale meaningful impact while basically
| grandfather in stuff like depleting the Great Salt Lake,
| coal emissions, etc. which have _vastly less_ regulatory $
| spend per environmental impact.
|
| Ideally, if we could quantify all environmental impacts
| into a single number (ie. CO2 emissions but also wildlife
| impact, etc.), the $/impact spent across different fields
| would be equal.
|
| Currently, however, we are likely spending 100x+ on a per-
| impact basis on SpaceX regulation.
| mptest wrote:
| >while basically grandfather in stuff like depleting the
| Great Salt Lake, coal emissions, etc.
|
| Gee, almost as if decades of austerity politics, lobbying
| by financial interests, and regulatory capture has
| malformed a well intentioned regulatory apparatus? Seems
| like we need more regulation that's less interested in
| what "united citizens" have to say. (read lobbyists)
|
| How are you arriving at that assessment of regulation of
| spaceX? i'd be interested in reading more.
| whimsicalism wrote:
| Austerity politics? I don't agree, we have record
| spending as a percentage of gdp and are rapidly
| approaching sovereign debt crisis levels of
| mismanagement. We aren't Europe, we never really had an
| austerity moment.
|
| > How are you arriving at that assessment of regulation
| of spaceX?
|
| I mean, SpaceX launches simply do not have a large impact
| on the environment compared to say, all cumulative coal
| emissions in the US. The FAA AST budget (which is for
| SpaceX launches) is about 60 million. Total EPA budget is
| about 9 billion. That's about 160x the size of the FAA
| launch regulatory budget, but the environmental impact of
| things the EPA covers (and mostly fails to cover) is much
| much much more than 160x the impact of spacex launches.
| mptest wrote:
| What evidence do you have to disagree?
|
| Reagen's and thatcher's whole agenda can be summed up by:
| "the biggest lie is 'i'm from the government and I'm here
| to help'"
|
| Have you not paid much attention to politics since Reagan
| and Thatcher? Their whole objective was to hollow out the
| government piece by piece, then point to its declining
| performance as justification for getting rid completely,
| or to gut further. Repeat. This has been the modus
| operandi for conservative parties since at LEAST thatcher
| and Reagan.
|
| >we have record spending as a percentage of gdp and are
| approaching a sovereign debt crisis
|
| Yeah, it's those pesky regulatory agencies riding up that
| tally I'm sure, not the almost 1 trillion we spend a year
| perpetuating apartheid states or our military bases all
| over the world while 3 americans hoard more wealth than
| 50% of all americans combined. Silly, patently false
| defense for an already silly position.
|
| Couldn't be the trillions we spent on the war on
| "terror". Or the trillions we spend on futile measures
| like the war on drugs. It's def the ftc and the epa.
| Those lot. That's who's causing our problems. Yep. That
| makes sense.
|
| Are you serious? Either you're not a student of history
| or we have drastically different readings of the past 40
| years of american government.
|
| >We never really had an austerity movement
|
| Patently false, dishonest rewriting of history. Did you
| not pay attention to Reagan actually did?
|
| Reagan's whole thing was the whole govt helping is a lie.
|
| Reagan cut food stamps and almost all other spending
| while drastically increasing the military budget, cut
| taxes on the wealthy, deregulated in the name of
| austerity, got the war on drugs going to villainize his
| political opponents.
|
| You simply can not be serious. Maybe read Reagan's wiki
| page before writing such demonstrably revisionist
| history.
| coding123 wrote:
| Or dismantled, lol
| creer wrote:
| It seemed to not be FAA here, but the several other agencies
| that all had 60 days to respond. FAA fast-tracked it but
| couldn't fast track it past the other guys' 60 day allowed
| time.
| blackeyeblitzar wrote:
| Well that may still continue to happen. The wonderful and
| competent state of California is literally trying to block
| SpaceX launches over Musk's constitutionally protected
| political speech:
|
| https://www.politico.com/news/2024/10/10/california-reject-m...
|
| I cannot remember a more explicit case of authoritarian
| government abuse in a developed nation in recent memory, and
| it's especially infuriating given SpaceX and Musk are one of
| the most important and innovative companies and leaders of all
| time. No other country would think to look at such
| accomplishments and try to undermine themselves through petty
| politics and lawfare.
| blisterpeanuts wrote:
| It is a state commission composed of political appointees.
| It's unlikely it has the jurisdiction over Vandenberg to ban
| any activities, except when such activities violate state
| environmental laws. Even then, the federal government might
| be able to override them. It will be interesting to see what
| comes of this.
|
| Ideally, the commission will withdraw its objections and
| allow the launches; SpaceX obviously chose this site both for
| its proximity to the Pacific Ocean and for redundancy in case
| of poor weather in Florida (like this past week for example).
| blackeyeblitzar wrote:
| It has jurisdiction over Vandenberg for private launches,
| and there is debate over what counts as private versus
| federal. However, regardless of possible environmental
| concerns, they've already explicitly said they're targeting
| SpaceX because of Musk's political speech, which is morally
| reprehensible and also illegal per the constitution.
| neodymiumphish wrote:
| Can the federal government override them if the launches
| are purely commercial. Presumably that would be the case
| eventually, so I think it's something that needs to
| addressed sooner.
| kortilla wrote:
| Vandenberg does not provide redundancy. It accesses
| completely different orbital inclinations. You cannot
| launch east from there but you can launch south. The
| opposite is true in Florida.
| blisterpeanuts wrote:
| Seems like it nonetheless provides redundancy. Also, one
| site can only handle so many launches per day. If SpaceX
| gets really busy, it will need multiple launch pads to
| handle the traffic, both launches and landings.
|
| But then, there may be military missions that require
| launching from an air force base.
| SalmoShalazar wrote:
| I don't understand how this is a constitutional violation
| like you claim. Let's pretend he posted something absurd on
| Twitter for arguments sake, like "I'm going to use my rockets
| to kill every endangered bird on every California beach", do
| you think that should not be considered when evaluating the
| request for more launches?
| db48x wrote:
| It's straight up unconstitutional. It doesn't matter what
| the speech is, the government cannot make rules that
| discriminate on the content of the speech.
| cryptonector wrote:
| Congress shall make no law respecting an
| establishment of religion, or prohibiting the free
| exercise thereof; or abridging the freedom of speech,
| or of the press; or the right of the people
| peaceably to assemble, and to petition the government
| for a redress of grievances.
|
| The first amendment has been interpreted by the courts as
| applying to all of the government, not just Congress, and
| via the 14th amendment is has been incorporated against the
| States, meaning that it applies to them too.
|
| Therefore, for a California state government agency to
| punish SpaceX for its founder's speech is unconstitutional.
|
| Title 18 USC section 232 lays out criminal penalties for
| violating a citizens civil rights, thus unconstitutional
| acts can be and often are criminal acts.
| WalterBright wrote:
| California officials reject more SpaceX launches, with some
| citing Musk's X posts
|
| https://twitter.com/shellenberger/status/1845131546501734440...
| cryptonector wrote:
| That's madness. And unconstitutional.
| WalterBright wrote:
| Musk tweeted that he's filing a lawsuit Tuesday morning.
| mensetmanusman wrote:
| It's funny how much illegal stuff gets done by leadership.
| Sue to fix. Lawyers always win.
| mlindner wrote:
| The California Coastal Commission has no authority over a
| Federal (Military) launch range so there's no need for real
| concern. Yes using people's personal opinions for denial is
| illegal, but it's moot regardless. So I'm not sure SpaceX
| could sue for any damages.
| cdash wrote:
| They don't actually have any jurisdiction in this case.
| Launches from Vandendberg are from a military base and while
| they do try to work with the California commission they
| ultimately are the ones that decide what does and does not
| get launched.
| baq wrote:
| Congratulations. This is a Sputnik-level event, opening a new era
| in the history of civilization. Amazing.
| tekla wrote:
| The catch somehow absolutely demolished the amazing FH dual
| landing
|
| Holy shit. I almost had a heart attack when it looked like the
| booster was about to slowly careen into the tower
| TacticalCoder wrote:
| > I almost had a heart attack when it looked like the booster
| was about to slowly careen into the tower
|
| Same but it looks more dramatic on the feed we all got: on
| other vids the angle is different and although close it doesn't
| look it's going to crash into the tower.
|
| Still: feels pretty close.
| ryzvonusef wrote:
| First attempt!
|
| I can't believe what i just saw!
| zamadatix wrote:
| SpaceX has done it again! (defying status quo, not the catch :p)
| themgt wrote:
| NSF video:
| https://x.com/nasaspaceflight/status/1845442658203734384
| bearjaws wrote:
| Couldn't watch the livestream on X because it was erroring out.
| We live in a world where you can't stream a video or Chromecast
| on X but you can catch a damn rocket...
| dylan604 wrote:
| X has proven time and time again that it just cannot handle
| live feeds well.
| doug_durham wrote:
| I wouldn't bother with X. There were dozens of YouTube channels
| with the live feed.
| isbvhodnvemrwvn wrote:
| Live scams too.
| anonzzzies wrote:
| That was impressive.
| ETH_start wrote:
| SpaceX's Falcon 9 and Falcon Heavy have already revolutionized
| the space industry with their reusable first stage boosters and
| rocket engines. This advance in rocket design has resulted in the
| cost to launch one kilogram of payload to orbit from
| approximately $15,000 in the pre-SpaceX era, to around $1,400
| with the Falcon Heavy. This graph shows the incredible impact of
| SpaceX on the volume of rocket launches, with an exponential rise
| in recent years:
|
| https://ourworldindata.org/grapher/yearly-number-of-objects-...
|
| With Starship, SpaceX is striving to make rockets fully reusable,
| which, if they succeed, will transform human civilization by
| radically reducing launch costs and enabling large-scale space
| exploration and industry. The kinds of possibilities this opens
| up include economically viable permanent lunar bases, Mars
| colonization, and revolutionary industries like asteroid mining.
| dogma1138 wrote:
| When KSP becomes reality, 275 tons falling from space caught by
| some metal struts...
| travisporter wrote:
| Ryan Hansen had an incredible (although unofficial) 3d modeling
| video of the mechanism. https://m.youtube.com/watch?v=ub6HdADut50
| cam72cam wrote:
| Absolutely incredible achievement, I'm still shaking!
| renewiltord wrote:
| This is amazing. What an incredible technological feat!
| tayloramurphy wrote:
| This got me as excited as the original Falcon 9 landing in 2016!
| Now I got to share this with my kids! So incredible...
| Gud wrote:
| One of the biggest steps forward in the space industry since the
| first landing of Falcon 9.
|
| Great success!!
| grecy wrote:
| Happy Birthday! SpaceX lit a mighty big candle for you :)
| Gud wrote:
| Thanks! And they sure did!
| fragmede wrote:
| basically they transfer equipment from the rocket to the landing
| tower so that the rocket can be lighter which is why they have to
| catch the rocket instead of the rocket landing by itself.
| ungreased0675 wrote:
| Wow, that's amazing. Didn't think something like that would be
| possible.
| ftio wrote:
| What an incredible achievement. Huge congratulations to the team
| at SpaceX! Still have chills.
|
| Anyone know whether the fire toward the bottom of the booster
| during/after the catch is normal?
| nine_k wrote:
| I suppose they were venting off and burning some remaining fuel
| in some conduits.
| 1970-01-01 wrote:
| Landing from space during sunrise while your rocket is on fire is
| as dramatic as it gets!
| bloopernova wrote:
| Giddy and crying.
|
| I turned 50 yesterday and it feels a bit like the future I
| dreamed of as a child.
| Yacovlewis wrote:
| This made me happy
| 93po wrote:
| I also cried watching this
| DarmokJalad1701 wrote:
| Right on target, next to their buoy! Insane achievement!
| pfdietz wrote:
| At a buoy, SpaceX.
| ryzvonusef wrote:
| the starship hit the target!
| t1234s wrote:
| Do they recover whats left of the ship from the Indian Ocean?
| eqvinox wrote:
| They can probably go fishing, but anything that sunk is gonna
| stay sunk. That ocean is not shallow, and deep submarine
| operations are _expensive_ ...
| dotnet00 wrote:
| They did pull the bottom of the previous booster out. On the
| webcast they mentioned adjusting the landing maneuver for the
| ship to be a bit softer in case they decide to recover it
| too.
| Klathmon wrote:
| The previous booster landed in the golf of Mexico.
|
| This starship landed in the Indian ocean a bit west of
| Australia, it's like 3x deeper.
| eqvinox wrote:
| | That.
|
| For extra context: that "3x deeper" makes costs seriously
| explode. People do know how to engineer for that depth,
| but it's a lot of effort and there's pretty much no
| commercial market. For shallower stuff there's oil rigs,
| deep-sea cables, seafloor mining, even just tourism...
| but at some point it just peters out and only research
| vessels tackle the depth.
|
| (source: friend of mine works at a UK university doing
| deep-sea vehicles)
| RaoulP wrote:
| >(source: friend of mine works at a UK university doing
| deep-sea vehicles)
|
| As in he works on their development? That sounds
| exciting, do you have something like the name of one of
| the vehicles?
| eqvinox wrote:
| > As in he works on their development?
|
| Yes, she works on their development.
|
| > That sounds exciting, do you have something like the
| name of one of the vehicles?
|
| No vehicle name, but this is the university
| department/lab: https://www.southampton.ac.uk/research/fa
| cilities/maritime-r...
|
| (Their vehicles don't even go _that_ deep, but again that
| was the point I was trying to make... even in research,
| the very deep stuff is rare and a "big project" that
| ends up fanned out = MRIL made only the cameras for a 4km
| vessel...)
| t1234s wrote:
| Do they worry about any issues of the debris winding up in
| the hands of China or Russia? I would imagine the raptor
| engines are mostly intact.
| rapsey wrote:
| You think there are Russian submarines in the gulf of
| mexico?
| eqvinox wrote:
| They splashed down in the Indian Ocean, not the Gulf of
| Mexico.
|
| Also noone mentioned submarines, debris can just float
| and drift around (sometimes even at some depth below the
| surface).
| Denvercoder9 wrote:
| Starship landed in the Indian Ocean, not the Gulf of
| Mexico.
| perihelions wrote:
| I mean, yes [0]. It's probably the main reason SpaceX
| went to effort to recover [1] all the engines of the
| previous booster (IFT-4), which landed in accessible,
| shallow water in the Gulf of Mexico. The Raptor engines
| hold valuable secrets, particularly to China who are
| trying to clone a lot of SpaceX things.
|
| The CIA did something very similar to this in the Cold
| War [2], though they used a boat instead of a submarine.
|
| [0] https://en.wikipedia.org/wiki/Akula-
| class_submarine#Operatio... ( _" In August 2012, the news
| media reported that another Akula-class submarine
| operated in the Gulf of Mexico purportedly undetected for
| over a month, sparking controversy within U.S. military
| and political circles..."_)
|
| [1] https://old.reddit.com/r/SpaceXLounge/comments/1fvdek
| t/more_... ( _" More images from B11 recovery + new info
| "26 of the Raptors have been recovered but they are
| trying to get all 33"_)
|
| [2] https://en.wikipedia.org/wiki/Project_Azorian
| phkahler wrote:
| Was the explosion intentional? I thought they were hoping
| it would float for recovery but if not I makes sense to
| sink it.
| renewiltord wrote:
| Do they have the ability? Russia couldn't get Kursk back.
| Not clear they could even do it if we left it there.
| eqvinox wrote:
| It's more of a financial question, do you want to shell
| out for some chance at it. And Russia and China can build
| their own engines, SpaceX is _very good_ but not like _a
| century ahead good_.
|
| (If anything, I'd be more worried about North Korea or
| Pakistan getting their hands on stuff...)
|
| Either way the risk is the shit that's left floating, if
| they don't fish it out it'll randomly wash up in
| Madagascar or so...
| skrebbel wrote:
| Can someone explain to me why this is more impressive than
| landing the rocket? To a layman like me, it looks very similar -
| the thing looks just like a rocket but without a pointy tip, and
| on the way down I don't understand why difference that matters.
|
| (I mean I still think it's mind blowing, because I think landing
| a rocket is also mind blowing)
| jq-r wrote:
| From what I understand, it reduces the turnover dramatically.
| In theory the booster should be refuelled, new second stage
| mounted on top and ready to go for another flight. So could cut
| down from weeks to days/hours. That's significant.
| Denvercoder9 wrote:
| It is a rocket. The biggest difference with the Falcon 9 first
| stage is that this one is about 6 times as big (diameter of 9m
| vs 3.7m), and that catching it with the tower requires a much
| higher precision in landing location. The drone ships that
| Falcon 9 lands on are about 90 x 50 meter. To catch it with the
| tower, they need to be accurate to within a few meters.
|
| The big advantage of catching it with the tower is that it'll
| (eventually) allow them to put another Starship on top, refuel
| and launch again within hours, as opposed to the weeks it
| currently takes for Falcon 9.
| HarHarVeryFunny wrote:
| The critical differences between Falcon 9 first stage and the
| Starship booster is that Starship booster lands using 3
| engines rather than 1, and can throttle them down much
| further. 3 vs 1 gives Starship more directional control for
| precise landing (critical for this "catch" maneuver), and
| throttling allows it to hover, as it does right before the
| "catch".
| Denvercoder9 wrote:
| Falcon 9 also lands using 3 engines on its most demanding
| missions. The throttling is definitely an advantage.
| xcskier56 wrote:
| But as far as I know, one Merlin engine produces more
| thrust than the empty booster weighs which means they
| have to time things perfectly to get to zero velocity
| exactly at the ground.
|
| Super heavy can hover and even go down by throttling down
| more. This gives them more control for the landing and
| don't have to time it exactly perfectly
| skrebbel wrote:
| Thanks!
| wwarek wrote:
| It's more precise than landing on the ground, there is
| coordination with the tower required, it is way bigger than
| Falcon 9.
|
| This video goes into details pretty well:
| https://m.youtube.com/watch?v=OYvWYp0--bQ&t=832s
| linuxfan2718 wrote:
| This method doesn't require landing legs on the rocket,
| allowing their weight to be used for payload instead
| MattRix wrote:
| It's also already on the tower that it launches from, which
| drastically reduces the expense and complexity of setting it
| up for its next launch, making it easier and faster to reuse.
| inglor_cz wrote:
| To expand on this, landing legs of Falcon 9 weigh two tons.
| Landing legs of SuperHeavy booster would have to be even more
| formidable.
|
| Which means that the weight savings are nontrivial with the
| "catch the rocket!" landing method.
| throwaway4aday wrote:
| The tower is also how they plan to perform maintenance and re-
| staging for another launch. The tower can place it back on the
| launch structure or lower it down to the ground if it needs to
| be transported back to an enclosure for extensive repairs but a
| lot of work is just done with it at the tower. I imagine the
| goal is to eventually get to an automated system that catches
| the booster, inspects it for damage, clears it for relaunch,
| positions it on the launch structure, grabs another Sharship
| second stage and stacks it and then refuels the whole system
| and launches as soon as possible.
|
| Plus it's really big https://images-
| bonnier.imgix.net/files/ill/production/Starsh...
| stetrain wrote:
| This booster is significantly larger than anything landed on an
| orbital launch before. Here is a size comparison, previous
| largest landed orbital rocket stage is the SpaceX Falcon 9
| (three of them launch together as Falcon Heavy) on the left.
| Starship is on the right.
|
| https://upload.wikimedia.org/wikipedia/commons/7/7b/SuperHea...
|
| Landing via tower catch versus on a pad is advantageous because
| the weight of adding retractable landing legs to such a large
| rocket would be significant.
| skrebbel wrote:
| Thanks!
| creer wrote:
| (1) Much larger than any previous rocket landing, (2) This
| rocket carried no landing gear (more efficient - landing gear
| is heavy), (3) This rocket landed right back at the place it
| needs to be to launch again - right on its launch tower - which
| in a routine situation might make it much faster to prepare it
| for the next relaunch. (4) It's yet another step in control
| prowess - impressive in itself.
| creer wrote:
| I must say though "right on its launch tower" is fun and
| all...
|
| but things would have to get pretty extreme in the "routine"
| dimension for that to be very useful. If there are 20 first
| stages and 5 land/launch towers, for a first stage that only
| spends an hour in flight in between inspections.... well are
| you going to keep them parked on a scarce launch tower for
| maintenance? The towers with fill/launch infrastructure (such
| as reinforced concrete, fuel tanks, cold filling system,
| deluge water system) become the bottleneck. It's more likely
| then that the 1st stage lands, is safed, then is taken a
| couple hundred yards away for inspection and maintenance
| while the next in line is moved to be stacked for the next
| launch. The inspection / maintenance would have to be truly
| minimal (think airliner) to keep it right there on its own
| relaunch tower.
|
| "No landing gear" is more key, compared to Falcon 9 - because
| of the effort toward minimal launch cost.
| throw4950sh06 wrote:
| > The inspection / maintenance would have to be truly
| minimal (think airliner) to keep it right there on its own
| relaunch tower.
|
| That's what they are aiming for, eventually.
| skrebbel wrote:
| Thanks!
| ErneX wrote:
| This one seems way harder than the others which land on legs
| and on a relatively larger circular landing pad, this one needs
| to nail the tower and its arms.
| h_tbob wrote:
| I think landing a booster is just as impressive. It's just that
| nobody's done this before, so it's exciting! Plus it's a lot
| bigger and part of a fully reusable config which has huge
| implications for space travel.
| banku wrote:
| This is incredible!
| systemvoltage wrote:
| Closeup of chopsticks as they were catching the booster, best
| clip from Everyday Astronaut's livestream:
| https://x.com/kagurazakimoto/status/1845447451592765820
| renewiltord wrote:
| The SpaceX clip is better
| https://x.com/spacex/status/1845442658397049011?s=46
| systemvoltage wrote:
| Better than both, NSF's stream:
| https://x.com/nasaspaceflight/status/1845442658203734384
| renewiltord wrote:
| It genuinely was. Thanks for that!
| systemvoltage wrote:
| Insane!
| cubefox wrote:
| And here is the most beautiful shot:
| https://x.com/Cosmo_556/status/1845554958604657051
| nomilk wrote:
| I'd never considered a 70m tall chunk of mostly metal "agile",
| but the way it's controlled into the arms so precisely is
| something to behold.
| systemvoltage wrote:
| Do you know what the entire booster is hanging off of? It
| can't be the fins. How is the load transferred to the arms?
| SAI_Peregrinus wrote:
| The grid fins are what it's hanging off of.
| systemvoltage wrote:
| https://x.com/marionawfal/status/1845351598874120662
|
| I dug into it, found this clip. Elon says that it's those
| two tiny knubs! Saw a few pictures and yes, I confirm,
| it's not the grid fins.
| 93po wrote:
| that is a ridiculous amount of weight held by such a
| small thing
| db48x wrote:
| Small is relative. They're about 7 inches in diameter:
| https://www.youtube.com/watch?v=ub6HdADut50
| nomilk wrote:
| Great find. Still image from the video:
| https://imgur.com/a/3VHsZV9
| grecy wrote:
| The booster landed on "pins" that are structural load
| points and designed to support it's weight.
|
| Here is a brilliant profile shot looking down one of the
| "arms" after the catch today, you can clearly see it
| resting on the "pins", not the grid fins.
|
| https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2F
| 7...
|
| They also use those "pins" to raise/lower it with a crane
| when they need to during construction and during transport
| to the launch tower. It's the primary mode of lifting the
| thing
| bunabhucan wrote:
| There are two lifting points on opposite sides just below
| the fins.
| olalonde wrote:
| Anyone knows how the landing is guided? Is it just really precise
| GPS/altimeter or does it use computer vision?
| pfdietz wrote:
| I'd imagine a combination of inertial and GPS, combined with a
| Kalman filter. Inertial handles short term estimation; GPS
| correcting drift in the inertial system. But they could roll in
| other information sources at the end.
| imglorp wrote:
| For the centimeterish precision needed to hover into the
| chopsticks, they also have the opportunity to use signals
| from the tower area for final alignment. I'm thinking riding
| a beam like aviation ILS. Just speculating but it would be
| easy to implement.
|
| Optical/camera alignment is probably out of the question due
| to fire and smoke.
| pfdietz wrote:
| The arms themselves could have sensors on them. Inductive
| loops sensing the presence of the stainless steel
| structure?
|
| Also, I doubt centimeter scale precision would be needed;
| the arms have some compliance in them, I'm sure, as well as
| the ability to control how far in they swing.
| imglorp wrote:
| Yeah really - it's half centimeter nav according to BG.
| Ctrl-f for centimeter:
|
| https://arstechnica.com/space/2024/10/spacex-catches-
| returni...
|
| Surveying GPS can do that with WAAS and a bunch of
| integration time and extra receivers, but not in real
| time:
|
| https://www.gps.gov/systems/gps/performance/accuracy
|
| So that's why I think they need to have a high
| resolution, close range, 3d positioning method for the
| final seconds.
| mt_ wrote:
| I would bet in the traditional sensors.
| dotnet00 wrote:
| Likely a mix of GPS, inertial guidance, vision and radio/laser
| beacons/ranging.
| generuso wrote:
| Falcon-9 relies on GPS and a couple of altimeters. (Filtered,
| as others have already said, with the help of data from the
| inertial sensors.)
|
| Compared to Falcon-9, Starship/Superheavy additionally has a
| command link from the ground. Whether it is used to coordinate
| the movement during the catch is not publicly known, but it is
| easy to imagine how this could be useful.
| shirro wrote:
| They have the experience and control systems to do this reliably
| with Falcon 9 so it seemed doable in time but seeing it on a new
| vehicle on the first attempt was still surprising. Really
| impressive engineering.
| h2odragon wrote:
| My wife asked "Why is this a big deal?", so I gave her a link to
| Handmer's 2021 explanation:
| https://caseyhandmer.wordpress.com/2021/10/28/starship-is-st...
|
| She's not an enthusiast; she's got an impression from SciFi that
| going to mars shouldn't be that hard.
| moffkalast wrote:
| Well I mean going to Mars isn't _that_ hard per se, a fair few
| countries have done it... but carrying enough supplies and
| shielding to last people 2 years until the return trip and then
| actually getting back are way harder problems.
|
| Seeing Starship get burnthrough on these suborbital launches
| really shows how hard it'll be to do Mars return entry with a
| fair few extra km/s.
| diebeforei485 wrote:
| Only the US and China have landed successfully on Mars. China
| achieved this in 2021. Russia/USSR tried multiple times and
| didn't succeed.
|
| Other countries have sent satellites to orbit around Mars,
| which is not the same thing.
| spacesanjeet wrote:
| I think that the number of countries reaching Mars (lander
| or orbiter) is in single digits and thus when talking about
| how hard it is to reach Mars and then come back, both of
| the scenarios kind of hold similar weights.
| cyberax wrote:
| > Russia/USSR tried multiple times and didn't succeed.
|
| Pedant mode: the USSR did land softly on Mars, but the
| lander got caught in a dust storm and was not able to
| transmit back the data (
| https://en.wikipedia.org/wiki/Mars_3 ).
| m4rtink wrote:
| The european Beagle 2 probe apparently survived as well,
| but failed to deploy:
| https://en.wikipedia.org/wiki/Beagle_2
|
| But other than that, yeah, there are two Schiaparelli
| craters now on Mars. :P
|
| (https://en.wikipedia.org/wiki/Schiaparelli_EDM)
| mrandish wrote:
| Getting to Mars is hard but not _that_ hard compared to
| getting a large payload to Mars surface and back to Earth.
| Some people may assume Mars return is around twice as hard
| but it 's orders of magnitude harder. And that's before even
| contemplating doing so with a cargo of humans and the
| necessary tonnage for them to survive on Mars at least 26
| months.
| wolf550e wrote:
| Robert Zubrin's Mars Direct would have got "flags and
| footprints" on Mars without needing something like Starship. He
| worked on a version of SLS in 1989 in Martin Marietta that
| would have cost $1B and been ready in the second half of the
| 90s and would be retiring soon after many successful flight to
| Mars (and to the Moon), but instead we got SLS and Orion so we
| need Starship to get anything done.
| hnpolicestate wrote:
| Didn't Von Braun have a plan too? Nuclear rockets or
| something.
| wolf550e wrote:
| The difference is that Mars Direct was a conservative plan,
| wrt rocket technology. It just used existing Shuttle parts
| and was meant to fly from Shuttle pads in between Shuttle
| flights. It didn't require developing anything new, that's
| why they were sure it would be cheap and fast, and flight
| rate would make it possible for it to be reliable. SLS is
| that idea turned into a jobs program.
| boznz wrote:
| Regulations are hard enough just using methane, I wouldn't
| want to be the one filling out the paperwork if that was a
| nuclear rocket.
| davedx wrote:
| The Mars Direct book is worth reading not only for things
| like transport and mission design but also a wealth of other
| good ideas about how to "live off the land" when we get there
| too. Truly worth reading for anyone remotely interested in
| space exploration
| kqr2 wrote:
| How does this differ from his other book _The Case For
| Kats_?
| wolf550e wrote:
| The Case for Mars is the book about Mars Direct
|
| https://en.wikipedia.org/wiki/The_Case_for_Mars
| m4rtink wrote:
| Can recommend the book as well - its still not that dated
| and provides a very good overview of how not just a real
| missing to Mars, but also a sustainable settlement might
| look like. :)
| adastra22 wrote:
| Typo?
| rkagerer wrote:
| That seems like way too long an article for a non-enthusiast.
| h2odragon wrote:
| good point. we're geeks and do this kind of thing to each
| other. among normal people it might be rude.
|
| she got me a while back with ink solvents. Monks may have
| been more illuminated making those pretty manuscripts than we
| appreciated.
| DantesKite wrote:
| If you toss it into Google's NotebookLM, it'll probably
| produce a much more accessible version of the blog that's
| succinct and easier to parse in a few minutes.
| jader201 wrote:
| That's exactly what I did, and it seemed to do a good job
| of hitting the main points in about 13 minutes (which is
| much quicker than how long it would take a slow reader
| like me read this article).
|
| I'm sure it still didn't do the article justice, though.
| photochemsyn wrote:
| Going to Mars is relatively easy compared to setting up a self-
| sustaining human civilization on Mars, which will be thousands
| of times harder. Many people don't understand the scale and
| scope of the biosphere services the Earth provides to humans
| free of charge, though, and forget that little of that exists
| on Mars, other than gravity.
| jcgrillo wrote:
| I was sure they were going to lose one of the fins at "max q part
| 2".. Looked like it burned through near the hinge.
| _ph_ wrote:
| If anything, the last 2 flights have shown how good a decisions
| it was to go with steel. The thermal reserves seem to be really
| large. While not as bad as with the previous flight, there was
| still significant leakage of hot air between the starhip and
| the flap. But it didn't seem to cause significant damage, at
| least as far as for the landing. For complete reuse, they
| probably have to still improve that a bit.
| honeybadger1 wrote:
| What an inspiring team SpaceX has.
| lquist wrote:
| What does Starship reusability mean for $/kg to LEO? I know there
| are longer term targets of $10/kg but that supposes efficiencies
| that aren't here yet. Would be helpful to understand before
| Starship reusability where the state of the art was in terms of
| $/kg to LEO and where we would be with impending Starship
| reusability.
| acover wrote:
| https://www.reddit.com/r/SpaceXLounge/comments/1bgmsm9/cost_...
| augusto-moura wrote:
| I don't think we have a number for it yet. But it will
| definitely be the cheapest launch system at the time of launch.
|
| People say 200$/kg just with booster reuse, and 20$/kg with
| full reuse. Of course this might be too optimistic, but I truly
| believe we might reach under 50$ in this decade.
| quotemstr wrote:
| Even $50 is within "going to the moon for my honeymoon"
| range. Wow.
| augusto-moura wrote:
| $50 is a number for LEO (Low-earth orbit). $/kg to a Moon
| orbit (or flyby) might be significantly more expensive. Not
| only that, because it is further so it needs more fuel, but
| also it is a few days trip which would need a bunch more
| kilos in provisioning food, water and other things. So
| yeah, unfortunately not that cheap to have a honeyMoon in
| the moon (heh)
|
| There is a lot of possibilities to make a trip to the moon
| cheaper though. If we make LEO that cheap, we can build a
| lot of infrastructure in the space that would make the
| tourism to moon more affordable. Like keeping a few
| starships always in orbit as some kind of space-hotel-metro
| system.
|
| This will probably take a few more decades, though.
| Valgrim wrote:
| Artemis by Andy Weir dwells a lot on this kind of
| infrastructure, but I never could understand the orbital
| mechanics described in the book.
| rkagerer wrote:
| Yeah it wasn't explained well in the book, but I did some
| reading of third-party sources and diagrams about the
| Uphoff-Crouch Lunar Cycler orbit, which helped (Wikipedia
| and the like).
| itishappy wrote:
| Only if you don't care about coming back!
| moffkalast wrote:
| This might be the best time to get into cubesat development
| as a hobby, lol.
| jackcviers3 wrote:
| What is a good estimate of the number of times these boosters
| and engines will be reusable?
| JumpCrisscross wrote:
| > _What does Starship reusability mean for $ /kg to LEO?_
|
| All we can say is under $1,000/kg. Which is conservative, that
| limit being about two thirds that of Falcon Heavy's theoretical
| cost to LEO in a reusable configuration.
| thinkcontext wrote:
| We can't give any estimate. The costs depend on how many
| times the stages are reused. They have targets but we don't
| know what will actually happen.
| thinkcontext wrote:
| The dominant variable is how often they can reuse the stages.
| Last I heard Musk was targeting dozens of reuses for the upper
| stage and hundreds for the booster. If they are short of the
| cost per kg goes up.
| asadotzler wrote:
| Everyone gets this wrong, cost is not price. SpaceX themselves
| launch Starlinks at about $1,200/kg but they charge customers
| closer to $12,000/kg. Do the math. Costs coming down are
| increases in SpaceX profits, not decreases in customer prices.
| 55555 wrote:
| Over the extremely long term in competitive industries,
| prices asymptote at ~costs. So it's still a generally useful
| measure, and in ~all cases, it's at least a directional
| indicator.
| IshKebab wrote:
| Sure but currently this is not a competitive industry
| because nobody else can do this.
| TMWNN wrote:
| Besides what 55555 said, in the near term SpaceX has indeed
| passed at least some of the cost savings onto customers. NASA
| administrator Bill Nelson quoted a member of the Joint Chiefs
| as telling him that SpaceX had saved the US government $40
| billion for just launching military payloads.
| <https://www.fool.com/investing/2022/06/05/did-spacex-
| really-...>
|
| On the civilian side, SpaceX saved NASA $2 billion for just
| _one_ payload, Europa Clipper
| <https://arstechnica.com/space/2023/10/a-year-from-launch-
| the...>, so who knows how many billions more from other
| launches.
| cryptonector wrote:
| Sounds like those savings exceed the subsidies that some
| love to point out SpaceX has gotten from the government.
| season2episode3 wrote:
| If only the military budget went down by 40b in response to
| these new cost savings.
| max_ wrote:
| At this point I am finding it hard to hate Elon Musk.
|
| For everything he does that has annoyed me (like Gloating at
| people being bombed in the middle east) -- his business acumen
| has completely unlocked for people what they we thought was
| impossible.
| sbuttgereit wrote:
| People are complex. This is nuance.
|
| There should be nothing wrong with recognizing that any
| individual is a mix of things you're going to like and things
| you're not. That could be judged all the way to a mix of things
| which are morally correct, amoral, or immoral... but the
| reality is probably a mix.
|
| It should be OK to praise the guy for those good traits and in
| turn to criticize the guy for what he does wrong: both in turn
| calling out the specific actions and less "the person". Its
| rare that demonizing someone is really appropriate or anything
| other than self-serving and we should see those that make that
| effort in that light.
| FrustratedMonky wrote:
| Completely agree. But regardless of if we criticize or
| praise. He is gossip worthy. Going from being in a Marvel
| Movie as the architype of Iron Man, all the good things he
| has done, to recently jumping around at a rally of a madman,
| and kind of looking nuts himself.
|
| It does beg comparison to the typical evil genius. He could
| literally be a villain from a Bond Movie, funding Specter.
| It's all fun and games. But just on surface, it is hard not
| to talk about him. He embodies too many sci-fi tropes.
|
| On days like today, that was amazing to see. I'd like to
| think all the bad is overblown.
| nemo44x wrote:
| Yes he's amazing and we're lucky to live in a time and place
| where he can lead thousands of people that can do these things.
| He's an example of what's possible by a capitalist and how
| capitalism empowers individuals to shape the world and make it
| better for everyone. So naturally there's a group of people
| trying to stop him due to envy and other copes.
| FrustratedMonky wrote:
| Think you are confusing capitalism with variety of other
| political fields.
|
| Capitalism does nothing to ensure personal/individual
| freedoms. There is no 'empowering'.
|
| Technically slaves were also a valuable part of the
| capitalist system at the time. They were integral to the flow
| of capital, as they were an asset.
|
| You can have Dictator/Authoritarian governments also be
| capitalist. Huge misunderstanding these days is thinking
| China is communist. They stopped being communist decades ago
| and are not as Capitalist as the US. But that doesn't help
| individuals that much.
|
| Even today, Human Resources, is about 'humans' as capital,
| how to manage the human assets. Capitalism doesn't help the
| individual, the induvial is the resource to be mined.
| nemo44x wrote:
| China stopped being real communist because they were tired
| of starving. They are the proof that a centralized managed
| economy only leads to stagnation at best and mass death
| more commonly. Today they are a very competent cartel that
| takes a big on all free market production. Deng was mainly
| a genius and saved the country from Maoism.
|
| Slavery existed well before capitalism and is economic
| system independent. Slavery occurs across a wide spectrum
| of economic systems today. It will always exist. It's up to
| governments not capitalists to outlaw it. Capitalists need
| rules to play by.
|
| Human Resources are the socialist/communist/leftist
| contribution to our economic system. They can't actually
| contribute anything useful but they can deploy commissars
| to ensure the humans in the organization have right think.
| HR and all the associated schemes are simply leftist grift
| that infects everything.
| FrustratedMonky wrote:
| >>>China stopped being real communist because they were
| tired of starving. They are the proof that a centralized
| managed economy only leads to stagnation at best and mass
| death more commonly. Today they are a very competent
| cartel that takes a big on all free market production.
| Deng was mainly a genius and saved the country from
| Maoism.
|
| Doesn't change my statement that they aren't communist
| anymore, now. You are just agreeing. I didn't make any
| statement that was pro-communism.
|
| >>>Slavery existed well before capitalism and is economic
| system independent. Slavery occurs across a wide spectrum
| of economic systems today. It will always exist. It's up
| to governments not capitalists to outlaw it. Capitalists
| need rules to play by.
|
| Yes. That was my statement. That capitalism alone does
| not lead to individual rights. I guess you agree again. I
| miss-understood your previous statement that seemed to
| imply capitalism had lead to individual flourishing, and
| thus SpaceX.
|
| >>>>Human Resources are the socialist/communist/leftist
| contribution to our economic system. They can't actually
| contribute anything useful but they can deploy commissars
| to ensure the humans in the organization have right
| think. HR and all the associated schemes are simply
| leftist grift that infects everything.
|
| HR has nothing to do with socialism. It is clearly a Risk
| Management department. They are just as likely to fire
| victims as the guilty. The only calculation they use is
| the risk/cost to the company. If it is more expedient to
| get rid of a victim they will do it. They are not on the
| employee's side. If HR fires you for hanging a noose on
| your coworkers locker, that is minimizing the risk from
| someone unhinged.. That is not being socialist.
| tensor wrote:
| You should be glorifying Shotwell, not Musk. Yes Must helped
| give her room to build but she's the genius and deserves the
| credit.
| jpamata wrote:
| Is there any source for first-hand specifics of what she
| does?
|
| I used to argue in reddit (same username as my HN) basically
| calling Musk a fraud and Gwynne Shotwell being all the brains
| 6 years ago, but I've since changed my position after seeing
| engineers in spaceX give props to Musk at podcasts, twitter,
| and various interviews.
| panick21_ wrote:
| So funny that they had a little buoy water ready to film the
| explosion. I want to see the views of that camera from the
| landing itself.
| seydor wrote:
| Now we have no excuses
| metalman wrote:
| anybody not watching these live better be delivering a baby,or
| saving someones life its a very short list of things that should
| take precidence over what are the most astounding things
| happening for our species,ever
| nebben64 wrote:
| What is the object beside the rocket at 37:49 to 38:02 ? Is that
| debris ? It seems to be falling with, then away from the rocket.
| (it looks like a small glowing ring to the right)
| kevinmhickey wrote:
| It's the hot staging spacing ring. They didn't call it on the
| feed but it is an expendable part that ejects after separation.
| nebben64 wrote:
| thank you!
| Alex-Programs wrote:
| Hotstaging was added quite late so they need to jettison in
| order to land, but it should be permanently integrated in
| the later variants.
| nebben64 wrote:
| interesting, thank you for the extra info
| skizm wrote:
| This was insanely cool to watch. And on the first try!
|
| As a complete lay person with little to no physics knowledge:
| what stops the use of something dumb like a parachute, or even
| wings and landing gear, to "land" the booster? I assume it is
| impractical (since they don't do it), but what are the actual
| particulars that stop it from working? While super cool to watch,
| it seems crazy that plucking it out of the air like that is the
| best way to preserve the booster for reuse.
| ackbar03 wrote:
| physics?
| throw4950sh06 wrote:
| At the very least, reducing the number of concerns on the
| rocket is definitely worthwhile. They are going to have an
| engine in any case, and using just that and nothing else on the
| rocket itself simplifies testing and reduces risk. The tower
| can have a separate testing and there's no way something that
| happens on the way to orbit and back breaks the tower.
|
| Wings, parachute, etc... All very easy to break or burn at
| hypersonic speeds, and very chaotic to control. It probably (
| _very_ probably) wouldn 't be possible to land back exactly
| where the rocket launched on wings or chutes - that would
| probably need an extremely long and wide runway, but compare
| the size of Starship to the Space Shuttle... It's like braking
| a toy car vs braking an actual truck.
| Veedrac wrote:
| The Starship second stage is surprisingly not all that heavy
| compared to the 78t Shuttle orbiter dry mass, despite the
| many-fold difference in volume and payload, plus Starship
| needing to be a legitimate second stage rather than just an
| orbiter.
| ivandenysov wrote:
| It mostly comes down to reducing extra weight. You have to
| carry those wings and landing gear upwards, which reduces
| useful payload weight. But having the booster right where it
| started also helps with reusability. No need to transport the
| booster from a landing strip back to the starting table
| murderfs wrote:
| > As a complete lay person with little to no physics knowledge:
| what stops the use of something dumb like a parachute, or even
| wings and landing gear, to "land" the booster?
|
| The main advantage is that you don't need to spend any of your
| payload mass budget on a parachute, or wings and landing gear.
| The secondary advantage over a parachute is that you don't need
| to fish it out of seawater and make your refurbishment process
| more of a pain in the ass.
| avhon1 wrote:
| Parachutes give little or no control over where and how the
| rocket lands, are unreliable (unfurling fabric behaves
| chaotically; modern spacecraft still don't have 100%
| reliability on their parachutes), and are surprisingly heavy.
|
| Wings and landing gear are useless extra weight during launch,
| and excess weight on the booster has a super-linear reduction
| weight delivered to orbit. (the Tyranny of the Rocket Equation)
|
| During the 1960s, NASA investigated using inflatable Rogallo
| Wings (basically hang gliders) to land the Gemini capsule. It
| worked fine, but was more complicated than parachutes, and re-
| use was not one of the goals of the Gemini or Apollo programs.
|
| None of those give much margin for error on landing. Without
| any kind of propulsion, there's no option to come to a hover or
| do another go-around if the landing isn't going well. Space
| Shuttle pilots had to do extensive training in simulators for
| the landing because they only got one shot at it during the
| mission.
|
| Propulsive landing doesn't require any hardware that isn't
| already on the launch vehicle, only a little excess propellant.
| (And it is a small amount; Super Heavy is like a soda can
| that's full of liquid at launch and only has a swig at the
| bottom during landing.) Propulsive landing gives Falcon 9 and
| Super Heavy the ability to overcome wind and other weather
| conditions to make pinpoint landings. Engine throttling gives
| Super Heavy the ability to hover, so it has a huge margin for
| error when coming in for a landing.
|
| Super Heavy could have had legs, like Falcon 9, but it has such
| a huge payload capacity that they can simply choose to always
| launch with enough propellant to come back to the tower, and it
| saves a lot of flying weight and complexity by simply not
| having them. The arms on the tower can be massively overbuilt
| to ensure however much reliability SpaceX wants.
| georgeburdell wrote:
| SpaceX has unbaked bread
| zeristor wrote:
| I went to follow this on the SpaceX YouTube channel since it is
| usually closer to real time.
|
| It seems someone hijacked and played a video of the previous
| launch. Just as we got to launch time it cut to a fake badly
| dubbed speech by Elon Musk going on about Bitcoin, with a handy
| QR code.
|
| This was a bit confusing but since it was 10 minutes in advance I
| managed to switch to another channel.
|
| Still amazing, even if the video glitched at the key capture
| point.
|
| And an hour later the Starship itself re entered to soft salty
| sea landing.
|
| I don't know how many prototype runs they need to do, I'm
| guessing they could stuff a shed load of Starlinks into the next
| one.
| tofuahdude wrote:
| Sounds like you were on a scam, fake version of the channel.
| sbuttgereit wrote:
| You need to look closely at the channel name in a URL and not
| just the branding signals on the page itself (logos,
| "presentation name"), etc. What you'll find is that the on-page
| channel name can be made pretty much anything as well as logos,
| banner's etc. But when you look at a URL that leads to the
| channel page, it's not the same and it doesn't have the
| verification check.
|
| There is a real SpaceX channel: https://www.youtube.com/spacex
|
| Note that it's just "spacex" and does have the verification
| mark. Also, SpaceX doesn't stream anything there (anymore):
| it's all just promotional videos... some of them are cool, but
| that's all they are. Nothing real-time. SpaceX only streams on
| X now, so I'd recommend one of the third party Youtube channels
| like https://www.youtube.com/@NASASpaceflight (which isn't
| NASA) if you'd prefer to stick to Youtube for such things.
| zeristor wrote:
| This was on the YouTube appleTV app
| sbuttgereit wrote:
| I don't have any Apple products, so I couldn't give you any
| advice here.
|
| My experience is that, while YouTube has a lot of content
| creators that I very much enjoy... I enjoy YouTube
| stewardship of the platform... less so.
|
| I have an admittedly old Chromecast Ultra and Pixel Pro 8
| phone which I usually use to control it. As they continue
| to upgrade the app and the service, they steadily make it
| worse and worse. Damn thing is almost unusable.
|
| In the end, I think they may well be poorly product
| managing themselves into a position where they could be
| vulnerable to a more able, savvy, and competent competitor.
|
| All this is to say you're probably just out of luck on
| being able to see these sorts of scams if you aren't
| already hip to them existing.
| jader201 wrote:
| Can I hijack this thread for an almost completely unrelated
| question that I have observed in nearly every simulation of
| movement in space, even from sources like NASA and SpaceX which
| "should know better"?
|
| And I'm mostly asking this out of scientific curiosity, not as a
| criticism.
|
| Why do they always portray movement in space by showing stars
| moving past the view at variable rates, or even at all?
|
| The opening screen of this video while you're waiting for the
| feed to start shows stars moving that seem to be only feet away,
| and only a few inches in diameter. Like little orbs of light just
| passing outside the window.
|
| Isn't this highly unrealistic, for even extremely fast travel in
| space?
|
| I would imagine at most you would see very slow movement of a
| very static field of stars. But every depiction in sci-fi, video
| games, and other simulations like in this video insist on making
| it seem like space is full of tiny 6-12" stars floating only feet
| away from each other.
|
| Is there any explanation where this could actually be considered
| realistic that I'm not thinking of?
|
| I'm just a lowly software engineer, so my expertise in this area
| is null. But from a basic understanding of stars and physics,
| this seems unrealistic.
|
| Admittedly, I guess it wouldn't be very exciting to view movement
| in space in a way that I'm imagining would be realistic, and
| maybe that's the only explanation there is/needs to be.
|
| But I guess I'm thinking that there would be enough people at
| SpaceX (for example) to scream "this is not even close to
| realistic!" for something like that to not make it to production,
| even if it is more exciting to watch.
| KoolKat23 wrote:
| If they were truthful, you'd think the picture was frozen,
| signal issues etc.
| herval wrote:
| I'm guessing when making an artistic depiction of something
| going very fast in space, that sort of parallax helps? The goal
| of consumer content (including the ones by spacex) isn't to be
| realistic, it's to entertain
|
| That said, "the expanse" is an exception here - they make it
| look as realistic as possible, including the battles where
| ships don't even see each other. Stars barely move on it too
| andrewflnr wrote:
| You're correct, it's hilariously unrealistic (IIRC requires
| actual superluminal speed), but people have been conditioned to
| accept it by various scifi media.
| buildbuildbuild wrote:
| Imitating science fiction is great marketing for a space
| company.
|
| Brand association with familiar depictions of "the future" is
| the goal, not realism.
| ordu wrote:
| _> Is there any explanation where this could actually be
| considered realistic that I'm not thinking of?_
|
| You could record the full trip, and then speed the record up.
| What the point to watch at thousand years of the record with
| slowly changing picture, if you can watch it in a few minutes.
| jader201 wrote:
| That's what I was wondering -- even if you sped up a
| realistic capture from space, wouldn't it still just look
| like stars moving at about the same speed?
|
| There might be small variances in velocity, but it seems like
| not near to the extent we see in these simulations.
|
| Again, this was mostly a theoretical/scientific curiosity --
| I understand why they do it like this, I'm mostly trying to
| figure out what real movement might look like, even at nX
| speed.
| lutorm wrote:
| As others have said, you're correct. But one reason for doing
| this, beyond just looking cool, is to give a visual cue for
| motion. The aim isn't primarily to _look_ realistic, but to
| make it as easy as possible to _interpret_ the outputs. Motion
| cues help with this.
|
| As an example, if you're watching an airshow against a clear
| blue sky, especially filmed with a long lens where you can't
| see the ground, it is very hard to understand what's actually
| happening because you can only see attitude changes, but not
| the velocity vector. Add just a few clouds in the background
| and the impression is very different.
| kylecordes wrote:
| In addition to the other ways this is incredible, it is a
| stunning achievement in software development.
| interludead wrote:
| The video looks like it's being played in reverse
| cs702 wrote:
| Awesome. Incredible. Inspiring. Words fail me.
|
| Heartfelt congratulations to the folks at SpaceX!
| goodgrief99 wrote:
| Why don't they mount moving video cameras? I mean, the second
| part of the fly is pretty boring. They shows us a view from 2
| static cameras. Is it so difficult to make one camera moving?
| With 360 degrees view. Show us the shape of the earth the full
| circle, show us the moon. Is it so hard?
| DiggyJohnson wrote:
| Yes what you're describing is nearly impossible.
| _flux wrote:
| I don't think they'd need to _actually_ have moving cameras
| (I think this is what the poster meant) to give a 360 degree
| view, but 360 degree cameras (well, 180 because they 're
| right next to an obstacle) that could be reprojected to 2d.
| lutorm wrote:
| The primary purpose of having those cameras is to gather test
| data, not provide entertainment.
| brcmthrowaway wrote:
| Does each engine have 6 degree of freedom to point its jet?
| lpribis wrote:
| No, each individual engine has 2 DoF (x-axis and y-axis
| rotation) which correspond to torque on x and y plane to the
| rocket. They need to use more than one at once (three in
| starship's case) pointing in different directions to get z axis
| torque.
| bjamesking wrote:
| I was watching a youtube stream with tens of thousands of viewers
| and 20 seconds before launch it switched to an AI generated video
| of Elon on stage talking about his "crypto currency program". It
| was so well executed and generated, it nearly felt real.
|
| The violent anger I felt and still feel for scammers has ruined
| my day.
| mlindner wrote:
| They do this every launch unfortunately. Youtube seems
| completely inept at stopping them. They make enough money to
| hire hundreds of thousands of fake accounts to subscribe.
| macintux wrote:
| Musk choosing to abandon YouTube to push his other company
| didn't help.
| sebzim4500 wrote:
| True, but even before that there were fake spacex streams
| (complete with a 'verified account' symbol) with 10k+
| alleged viewers.
| ivewonyoung wrote:
| These are reruns.
| jvm___ wrote:
| They run even on daya when there's no launch or Elon
| presentation, I've watched one because I thought I missed some
| announcement.
| alceta wrote:
| Same here. I was actively showing the (scammed) live stream to
| my 4yo daughter, and had to switch back to the live version for
| yet another 10minutes of wait.
|
| Quite the embarassment, I think I begin to understand how my
| parents feel when they are completely unaware of some technical
| aspects I try to explain, and how easy it would be to scam
| them. Seems like it is getting easier to scam me, too.
|
| To be fair, once they switched to Fakelon, it was quite clear.
| But I started the same stream again later as the YT app does
| not properly highlight the channel's name before clicking.
| diamondfist25 wrote:
| YT and Google has a vested interest to defame Elon.
|
| It's very clear -- all the MSM are top of the list for anything
| Trump related, and for Elon it's all crypto scam channels
|
| It's intentional folks
| VohuMana wrote:
| Wow, I knew they were going to try to catch the booster this time
| but I really didn't think it was going to work on the first try,
| I was just hoping they didn't destroy the launch tower in the
| process. Congrats to the SpaceX team, absolutely amazing! Hope
| y'all are celebrating
| beambot wrote:
| Highlights in a YouTube video:
|
| https://youtu.be/b28zbsnk-48?si=JamDRMuN07oWlcZi
| BurningFrog wrote:
| Do we know how much more efficient/cheaper landing by booster
| catch is compared to landing on a platform?
| malfist wrote:
| It's not just cheaper, it's preserving capacity. Every pound of
| landing gear you carry has to be offset with fuel to lift it,
| and then that fuel has to have fuel to lift it and on and on.
| rhegart wrote:
| Coolest video by far, but this still places 3rd for me behind
| F9's first landing, and the dual heavy landing. The future is
| bright!
| agumonkey wrote:
| SpaceX is really incredible in how regular the improvements are
| coming. Something in their structure is well balanced.
| bamboozled wrote:
| It has to be Elon, he is focusing a lot of energy on the
| company right now.
| shmerl wrote:
| Given his completely horrible jerk personality, I'd expect
| the opposite.
| briandw wrote:
| Imagine the number of amazing space telescopes that we are going
| to get! When it's cheep to launch a 10m diameter object into
| space, so many possibilites open up.
| _ph_ wrote:
| For things like that, they could build special versions of the
| star ship which remain in orbit as the housing. They would need
| no flaps, no tiles, just the 6 engines and the fuel tank. The
| body of the starship itself would be the telescopes tube.
| Teever wrote:
| You could do that, you could also use it to transport pieces
| of massive telescope arrays that self assemble in space.
| _ph_ wrote:
| Sure, thats what they did with the JWST. But that ist
| complex and expensive. A custom Starship could be the
| cheapest way to get telescopes up to 9m mirror size into
| space as you can assemble everything on the ground and you
| don't need a separate housing.
| TyrianPurple wrote:
| "Any sufficiently advanced technology is indistinguishable from
| magic." and what we have witnessed is magic.
| jeswin wrote:
| Speaking as a non-American. SpaceX just made one of the most
| significant technological leaps in the last decade. This is
| obviously hugely significant in many ways, including retaining
| the US military edge.
|
| Yet the US administration hasn't congratulated SpaceX.
| Incredible.
| stetrain wrote:
| https://x.com/SenBillNelson/status/1845461454977196294
| abathur wrote:
| What counts?
|
| The current head NASA admin (a political appointee) did it a
| few hours ago and it's retweeted on the official @NASA account.
|
| (not linking as peer comment already did)
| dtquad wrote:
| There has been some kind of beef between Elon Musk and the
| Biden administration even before Musk's public right-wing turn.
| For example Biden has given speeches praising US EV vehicle
| manufacturers and not mentioning Tesla but mentioning all their
| competitors.
| ivewonyoung wrote:
| Unions told Biden to ignore Tesla.
| https://www.wsj.com/politics/elections/how-elon-musk-
| broke-w...
| smoovb wrote:
| Yeah stuff like this -
| https://www.youtube.com/watch?v=s9ZmdIh1qpI
| jeffnappi wrote:
| It's unfortunate that Elon has made himself so visibly
| political, it casts a dark shadow on the great work of the
| people at his companies.
| throwaway69123 wrote:
| Hard to stay apolitical when the government excludes you from
| an EV summit and calls your competition the market leader, a
| bold face lie.
| robwwilliams wrote:
| Awesome achievement. Watched it with my sister at home and
| brought back memories from the 60s in front of the B&W TV
| watching some of the early amazing flights and landings.
|
| Question for hackers: How does this reorient space programs
| world-wide? If I were a politician or technocrat in China,
| Russia, or the EU this would feel like an inverse and intense
| Sputnik moment -- "holy sh--- we have to up our game!"
| creer wrote:
| Eventually it convinces everybody that "quantity in space" is
| possible. Moving to projects where you don't have to count
| every ounce. It opens the path to wild schemes, in amount of
| weight that could be moved.
|
| And why "eventually"? SpaceX should have already convinced
| people of that. Yeah it's not yet in production, but the
| momentum and progress have been amazing to witness.
|
| (The previous one was convincing everyone that there was lots
| of space for tech improvement. Wake up call achieved just a few
| years ago also by SpaceX.)
|
| See also this blog post:
| https://caseyhandmer.wordpress.com/2021/10/28/starship-is-st...
| creer wrote:
| An interesting question (because all the others will probably
| be too slow) is what does that change for SpaceX itself
| (which can be fast)?
|
| It gets to complete and upgrade Starlink. Sure. And that
| keeps it busy for what? Two years? At most. Sure. Done. Just
| kidding, that provides some background launches as a
| guaranteed customer going forward. But nowhere near enough to
| make a dent in what will be the new SpaceX launch capabiity.
|
| So what else can it do, that exploits its own launch
| capability?
|
| Going to Mars is not an obvious commercial venture - not at
| first - not until some government somewhere convinces itself
| to fund that.
|
| So what else? What can SpaceX do on its own with this launch
| capability?
| creer wrote:
| One answer might be "infrastructure". Infrastructure in
| space will become big if space becomes big (beyond
| launching telecom, observation and science - which are
| small for now, compared to their launch potential.) SpaceX
| will need infrastructure itself - like refueling, landing
| stuff in exotic places, cargo delivery to other spacecraft,
| de-orbiting stuff, spacecraft to spacecraft networking,
| bringing cargo back to earth, carrying / delivering crew
| around, spacecraft repair, emergency access, etc.
|
| A bit like Amazon then: if SpaceX needs some capability in
| their grand plan to Mars or whatever, they could try and
| package that as a commercial service after using the bare
| bones version for themselves.
| 93po wrote:
| thankfully elon has hundreds of billions of dollars and
| presumably will spend most of that sending shit to mars,
| either before he dies or as part of a trust. most of what
| we need to send there isn't expensive - electronics and
| steel and composite materials. the limiting factor isn't
| going to be the cost of stuff we send there, it's only
| going to be how many starships we can get flying and how
| often they fly
| cubefox wrote:
| > So what else? What can SpaceX do on its own with this
| launch capability?
|
| Apart from Starlink, not much I believe. The main thing
| will be the Artemis contract with NASA, which requires two
| figures worth of Starship flights to LEO to refill the
| Starship tanker to get the HLS Starship to land a few
| people on the moon.
|
| So I do think Starship will mostly generate money through
| NASA contracts, Starlink, and commercial launches. Though
| there aren't that many commercial launches currently.
| Perhaps there will be more once the launch prices drop due
| to reusability, though that remains to be seen. Developing
| a satellite is already more expensive than launching it.
| creer wrote:
| We saw that solar power venture unveil their idea. With
| lower cost/kg, there might be quite a few flights just to
| deliver piles of hardware in various new orbits. And
| these might require refueling launches as part of that
| process. Some delivered all in one place, some in
| separate locations.
| cubefox wrote:
| Yeah, there are some very speculative markets. Solar
| power from space, commercial space stations etc. The
| chances seem relatively low that those would develop into
| a big market and require a lot of Starship launches. I
| currently don't see a big space economy on the horizon.
| Space (LEO) tourism perhaps could be thing to some extent
| when Starship gets human rated for both launching and
| landing. Because a Starship could actually deliver larger
| quantities of people, unlike Dragon or Starliner
| capsules, but this is still many years away.
| asadotzler wrote:
| It doesn't. It makes one or two mega-constellations cheaper for
| their operators and therefor more profitable, but no one except
| telecom and sensor platforms really want orbit. It's useless
| for most things, far worse than working on the planet's surface
| where all the labor and materials already are.
| carabiner wrote:
| In Europe, ESA has been pretty open about trying to copy and
| play catch-up to SpaceX:
|
| > Q: Callisto looks very much like Grasshopper, the SpaceX
| Falcon 9 first stage reuse prototype.
|
| > A: Callisto is Grasshopper. The Chinese are also building a
| similar prototype, I have no problem saying we didn't invent
| anything.
|
| https://satelliteobservation.net/2018/06/02/cnes-director-of...
| erichocean wrote:
| Imagine not being Team Elon.
| perlgeek wrote:
| During/before the water landing of Ship, the telemetry indication
| for the rocket motors stayed off.
|
| Does that mean the landing burn was unsuccessful? Or was that
| just a glitch in the telemetry?
| stetrain wrote:
| In the video you can see the engines light (reflecting off the
| metal control flap and water) and the ship make a soft
| touchdown on the water. It then tips over and the tanks pop
| from the force of smacking the water sideways.
|
| So the landing burn seems to have been a success.
| sebzim4500 wrote:
| It's weird, that happened last time too so you'd think if it
| was a glitch they would have fixed it.
| FergusArgyll wrote:
| The joy on the faces of all the employees is infectious,
| congrats!
| gyre007 wrote:
| Incredible achievement, my American friends! Congrats! We,
| Europeans, can only feel jealous, but hey at least we have free
| [but comically broken and dysfunctional] healthcare, so, there's
| that. I hope you'll bring a lot more progress to humankind beyond
| space exploration!
| mrandish wrote:
| The long-term goal is becoming a multi-planet species, so in
| that context it's not about countries. Go Earth!
|
| (also, while NASA has been generally helpful to SpaceX's
| efforts, American FAA bureaucrats have managed to inject
| unnecessary delays and uncertainty into the process (in
| addition to some necessary delays).
| yborg wrote:
| Amazing achievement, but also reminds me that what NASA and its
| contractors accomplished during the 1960s still stands with
| current day systems engineering.
|
| The 3rd Saturn V launch put three men into orbit around the Moon.
| The 6th landed two of them there.
| h_tbob wrote:
| We live in a day and age where it seems that all the innovations
| we see now are new tech that has to do with electronics.
|
| Good to see some good ol hardware breakthroughs in another
| industry.
| dang wrote:
| [stub for offtopicness]
| rvnx wrote:
| Edited: Was asking what were all these deleted comments.
|
| Got my answer: it's a theory that SpaceX is a partner for the
| US DoD and is not just an internet provider.
| Culonavirus wrote:
| [flagged]
| JumpCrisscross wrote:
| > _What the f is going on in this_
|
| Genuinely curious if you find an answer.
|
| My first thought was nuclear anxiety; it's nice to feel
| like we have a secret shield in space. Then I saw Trump
| talked about it, so my current hypothesis is the partisan
| parroting that happens on both sides. (Or if someone
| _doesn't_ like military spending, maybe it's an anti-Musk
| thing?)
|
| That said, the three accounts that have been posting about
| it seem to _really_ like this topic [1][2][3], so maybe
| it's a niche thing. They all seem to really like one Reddit
| thread.
|
| [1] https://news.ycombinator.com/threads?id=forgot-im-old
|
| [2] https://news.ycombinator.com/threads?id=tbone902
|
| [3] https://news.ycombinator.com/threads?id=georgeg23
| perihelions wrote:
| I recommend emailing hn@ with your questions, even if you
| don't currently see any obvious reason to.
| JumpCrisscross wrote:
| Guessing the massive flag storm will ruin someone's
| Monday.
| 486sx33 wrote:
| I'm just talking totally out of my A S S. Wouldn't it be
| cool if this starship launch somehow utilized starshield
| for grabbing starship, like proof of concept to the
| military of some kind of hyper accurate military grade GPS
| that can pinpoint a rocket and control it to the accuracy
| of between two chop sticks?
| fasteddie31003 wrote:
| I hate to bring politics into such a momentous occasion, but as
| a lifelong Democrat, I think Trump might get my vote because of
| his alliance with Elon. Elon clearly is a once-in-a-century
| human who has progressed humanity more than anyone else in
| history. I think we need to let him achieve his goals without
| being burdened by government bureaucracy. Unfortunately, the
| Democrats have aligned against Elon. It didn't have to get this
| way, but it has. A Trump presidency will allow Elon to progress
| more, bringing humanity with him. I hate Trump and I think he
| is a narcissistic idiot, but he supports Elon more than Kamala.
| ilrwbwrkhv wrote:
| The great dichotomy of man. Elon is a hardheaded questionable
| fellow who stops free speech on his platform if it doesn't
| suit the agenda and is supporting Trump who literally spurred
| an insurrection.
|
| But Elon also started one of the greatest revolutions mankind
| has ever seen, up there with the Apollo project, which one
| can say is mankind's greatest achievement.
|
| What do you do with that dichotomy is up to you to resolve.
| grecy wrote:
| Elon will be able to achieve his goals just fine under the
| Democrats.
|
| Trump will run so much stuff into the ground nobody will be
| able to achieve anything.
| busymom0 wrote:
| Does anyone know what this circular thing is at 5:36 mark in the
| below video under the booster? It's like a piece which separated
| and keeps falling off.
|
| https://i.imgur.com/z6PH2Jw.png
|
| https://youtu.be/b28zbsnk-48?t=336
| hnpolicestate wrote:
| This is why Musk is silly when he claims fear over what certain
| possible gov administrations would do to him if elected.
|
| He's allowed to believe whatever he wants. He's too valuable to
| the United States. Imagine what a BRICS country would pay for his
| talent? Worth his weight in gold wrapped platinum.
| georgeburdell wrote:
| It's justified.
| https://www.latimes.com/california/story/2024-10-11/la-me-sp...
| ChuckMcM wrote:
| Pretty impressive. The engineering team at SpaceX is really
| something. Some thoughts;
|
| The 'chopsticks catch' was amazing to watch. Seems like it adds a
| lot of risk and clearly the booster needs additional fire
| suppression systems :-) perhaps the tower could mount something
| that sprays the booster like the barges have for the F9 boosters.
|
| The heatshield held out for a much longer time, the asymmetric
| heating on the flaps was interesting. I had guessed that all four
| flaps would have equivalent heating based on an approach that was
| basically that side of the rocket perpendicular to the flow but
| it seems like that isn't the case. Still it seems like they are
| close to having something workable here.
|
| The detonation at the end was pretty spectacular too, but I
| suspect that structurally the tanks failed as the rocket hit the
| water vs anything that was an engineering failure. Engineering it
| to be strong enough to land on water would presumably compromise
| the cargo to orbit number.
|
| The use of Starlink was really interesting. The ability to get
| live video for the entire re-entry is pretty game changing for
| engineering. I'd guess there are even more 'views' than they
| showed (there would be if I were running things :-)) but overall
| that capability is something that really helps evaluate the
| changes made.
|
| I can easily imagine that flight 6 will be nominal end to end
| without any unintended damage. That would enable, perhaps, one of
| their 'massive' Starlink missions to test cargo delivery. It will
| also start to give us some better numbers on exactly how much
| cargo Starship can put in orbit in 'full reuse' mode which is
| essential if they want to create a fueling station on orbit for
| the Artemis program.
|
| Again, hats off to engineering at SpaceX, y'all did good.
| nordsieck wrote:
| > The detonation at the end was pretty spectacular too, but I
| suspect that structurally the tanks failed as the rocket hit
| the water vs anything that was an engineering failure.
|
| It's possible that SpaceX programed the AFTS to trigger some
| time after the rocket touched down in the water. Just to make
| sure that it completely submerges quickly.
|
| > I can easily imagine that flight 6 will be nominal end to end
| without any unintended damage.
|
| I think it depends on what you mean by "nominal". SpaceX
| ultimately wants to catch the 2nd stage as well. I suspect that
| they are a ways off of that, since it would have to approach
| over land. The FAA is going to need to have very high
| confidence that it will do exactly what it's designed to do
| before they're going to allow that.
| 317070 wrote:
| > Just to make sure that it completely submerges quickly.
|
| Why would they want to do that? (genuinly curious).
|
| I reckon there would be a lot of useful data left if they
| could recover or even just inspect the remains. The remains
| are one big tank, so it would have floated.
| eco wrote:
| No doubt it would be very useful to recover. SpaceX isn't
| the only one who could pluck it out of the Indian ocean
| though. You don't want to leave a prototype for the most
| advanced Spacecraft ever made just sitting around for
| competitors to grab (most notably China which is currently
| speed running SpaceX-like designs).
| creer wrote:
| It landed right next to their own camera-bearing buoy.
| You can bet their own recovery ship was right nearby. And
| with access to radio control too. Likely with a couple US
| military ships on hand too.
| wiz21c wrote:
| I certainly hope so. Ocean are polluted enough and
| although such a ship is just a, well, drop in the ocean,
| the ideq of accepting to pollute more is unbearable to
| me, especially for a world class company like SpaceX...
| dzhiurgis wrote:
| Other than some electronics it's actually pretty clean
| vehicle - methane will gas off, steel will quickly
| disintegrate in water, there isn't tons of plastic or
| paint.
| inglor_cz wrote:
| Looking at the composition of the ship, it won't be
| polluting the ocean much. No people on board to produce
| trash etc., mostly just plain stainless steel and a bit
| of ceramics that will make great hiding spot for the
| abyssal fish for a few years.
| m4rtink wrote:
| It might not be that simple - I've read an article how
| they recovered one of the solid rocket boosters from the
| first successful Ariane 5 flight to check all was fine.
| IIRC it was a slog, they had to tow it back very very
| slowly, avoid it sinking, fighting all kinds of weather
| and tow line issues, etc. Have not found the article, but
| there is a picture how it looked like[0].
|
| With Starship it could have been similar & possibly worse
| given the size and more complex shape (various voids that
| might fill/drain & the thing is not really built for
| floating). Also you are in the middle of an ocean (Indian
| in this case) with potential for all kinds of weather on
| the way. Towing might again be very slow, so you might
| need to stage a massive submersible transport ship or
| something similar to make a recovery successful. And then
| the thing might still tip over and explode anyway -
| meaning all this was in vain.
|
| I think is most likely they won't bother and instead just
| stream as much data as possible over Starlink in real
| time (or heck, even via WiFi once the buoy is in range)
| for analysis. They want to catch the shop eventually
| anyway, so manual post flight analysis will wait.
|
| They can now check all over the first recovered booster
| anyway. :)
|
| [0] https://www.flickr.com/photos/europeanspaceagency/370
| 0131835
| 317070 wrote:
| But, couldn't they wait for like, 6 hours? Take a good
| look when it's cooled down a bit. Send some drones over
| to film it, and then sink it?
|
| I get that towing is probably too expensive for what it's
| worth. But I'm surprised they don't even go pick up some
| tiles before kablooing it.
| creer wrote:
| Attach a tether to one of the fin pods, then blow up the
| rest to sink it cleanly and bring back the important
| part.
| creer wrote:
| Possible yes but still, this is a prototype with new fin
| configuration, materials and lots of detail to be
| understood from inspecting it in detail. An inspection
| would be very useful.
|
| At the same time, this is SpaceX and they have a few
| others ready to launch already. Perhaps they indeed can
| keep it somewhat coarse and wait for detailed inspection
| until one of them makes it right back to solid ground?
| bombcar wrote:
| You wouldn't need to tow it; if you really wanted to you
| could use one of those deep see platform recovery ships
| that sink themselves. The rocket is big but it's tiny
| compared to ocean-going vessels.
| eco wrote:
| The previous ship did not come down where it was supposed
| to. I don't think they wanted humans anywhere near where
| it was coming down, at least until they can reliably do
| pinpoint landings. Even the Falcon 9, as accurate as it
| is, doesn't have humans anywhere near the landing
| location.
| esskay wrote:
| Yep this will be the reason. And lets not forget that
| Bezos was able to find and recover the Apollo 11 Saturn V
| engines from point nemo. If that was relatively simple
| you can bet plucking a freshly dropped entire starship
| from the indian ocean would be a doddle, especially when
| sat views likely show exactly where it landed.
| walrus01 wrote:
| I'm fairly certain the Apollo first stage engines were
| recovered from a location relatively close to
| Florida/Bahamas, just east of the launch site. Not point
| nemo.
| craigmoliver wrote:
| That is correct, off FL. The recovered engines were from
| the first stage they would never have made it half way
| around the world. Point Nemo is used to stash spacecraft
| that were in orbit.
| m4rtink wrote:
| Also a yacht of a fishing boat could run into it in the
| night and sink - eq it could become an unmarked floating
| hazard.
| iknowstuff wrote:
| correct me if I'm wrong but I don't think the second stage is
| meant to be caught. It will have legs to land on Earth/Mars
| without any landing infrastructure.
| sebzim4500 wrote:
| It will have legs for Mars but they plan on catching it on
| Earth.
| ls612 wrote:
| It is expected to land astronauts on the Moon as well this
| decade, which will certainly require legs.
| DarmokJalad1701 wrote:
| That is a different version. The ones launching/landing
| on Earth are supposed to be caught by arms similar to the
| booster.
| gibolt wrote:
| The ones for other celestial bodies are also planned to
| return to Earth... Being inside one as it does the belly
| flop will be quite the experience.
| ncallaway wrote:
| Pretty sure the Artemis lunar missions are going to use a
| different vehicle for Earth to LEO and LEO to Earth, so I
| don't think anyone will be inside a Starship belly flop
| for quite some time
| irrational wrote:
| Or have the tower on the moon catch it.
| kedv wrote:
| Why is SpaceX choosing to land the booster on the Mechazilla
| arms instead of performing a soft ground landing like the
| Falcon 9 booster?
| syncsynchalt wrote:
| 1) legs are heavy 2) empty rockets are stronger in tension
| than compression
|
| the scale of Superheavy is such that the above two items
| are making the arms scheme make sense. The number of
| engines also gives this rocket the ability to hover, which
| probably makes the scheme easier to pull off.
| anymouse123456 wrote:
| It's my understanding that these engines can be driven
| with variable power, which also makes deceleration and
| controlled hover more feasible.
| syncsynchalt wrote:
| This was also true for this engine's predecessor, the
| Merlin 1D. However that engine's rocket (the Falcon 9)
| can't hover, as the power of a single engine throttled to
| its lowest setting still overcomes the weight of a
| nearly-empty booster.
|
| All high performance engines tend to only throttle in a
| range in the upper half of the engine's performance, the
| difference making hovering possible in this case is that
| the Super Heavy has _so many_ engines that it can turn
| off. This is a sort of secondary throttling, or meta-
| throttling, and the rocket can use the combination of
| engine throttling and engine-off to hover comfortably
| (while near-empty) with three engines going.
| askvictor wrote:
| > 2) empty rockets are stronger in tension than
| compression
|
| True, but wouldn't the deceleration burn be putting much
| more compression onto the near-empty rocket than the
| landing?
| asdfadsfgfdda wrote:
| The engine load is probably a steady, consistent
| magnitude. While a landing load is rapid and variable.
| Also, you need to design legs for wind loading after
| landing, which can be high if you want to launch often.
| jve wrote:
| 3) rapid reuse by landing on launch tower
| avmich wrote:
| Spent rocket stages are empty of fuel, but not
| necessarily of the ullage gases, the pressure inside
| could be e.g. 3 atmospheres and that could be enough to
| provide some stiffness in the direction perpendicular to
| the axis.
| stetrain wrote:
| > It's possible that SpaceX programed the AFTS to trigger
| some time after the rocket touched down in the water. Just to
| make sure that it completely submerges quickly.
|
| The SpaceX host on the stream said that they were going to
| try and touch it down on the water at more of an angle than
| the previous flight to attempt to get it to survive the
| initial splash-down so they could get some more data and
| video footage.
|
| Obviously this wasn't guaranteed to succeed, but it indicates
| that they weren't planning to immediately detonate the ship
| on touchdown.
|
| As I recall it was common on the early Falcon 9 landing tests
| that splashed down in the ocean to also explode after tipping
| over and smacking the water. Once they're actually landing
| them on a pad, tower, or ship that should be much less of an
| issue.
| chippiewill wrote:
| Yeah, I don't think SpaceX planned for a RUD on tip-over
| (even if they did anticipate it).
|
| I think they've towed stuff in the sea before so I would
| have thought that'd be their preference if it were
| possible.
| stetrain wrote:
| Yeah. It wasn't planned, but was a likely outcome.
|
| I'm not sure if they would have actually attempted to tow
| this one somewhere given its location in the Indian
| Ocean, but they might have taken the opportunity to do
| some inspections before sinking it.
| Isamu wrote:
| I imagine that they will be their own first customer - putting
| Starlink satellites into orbit while they are gaining
| confidence in the reliability of the system for external
| customers.
|
| They have to prove out the landing of the second stage, either
| with another catch or with landing gear, which they need for
| the lunar lander anyway.
| ericcumbee wrote:
| I think that has always been the plan. the V2 starlink sats
| were designed to fly on Starship. When Starship wasn't coming
| along as planned they shoe horned the guts of the V2 on to a
| smaller sat that became the V2 Mini.
| norman784 wrote:
| If Im not mistaken, they already delivered a payload in one
| of the previous flights, because they cut the transmission
| for a while and didn't show the payload bay like one previous
| flight.
| oceanplexian wrote:
| I'm not sure they are, if only because of the altitude.
| They only took Starship up to 200km, Starlink are nearly
| double that so while they do have thrusters that's quite
| the distance.
|
| Starship is not really in a true orbit, I forget the exact
| terminology but the trajectory is designed to re-enter
| regardless of what happens with the the flight.
| ViewTrick1002 wrote:
| It is in an suborbital trajectory but with enough energy
| to be equivalent to reaching orbit.
|
| Think of it as instead of thrusting perpendicular to
| gravity for the most optimal energy usage Starship
| instead points its nose up gaining more altitude but now
| lacks the speed to miss earth as it comes down.
| m4rtink wrote:
| They actually made use of this this flight again - eq.
| they still did not perform a deorbit burn this flight &
| let the trajectory to pull them down to the atmosphere.
| creer wrote:
| They showed 4 streams at once during some of the reentry. One
| view of each control surface. They may have had still more
| views but just that 4 was a first.
| asdf123qweasd wrote:
| Imagine, linking that video into a 360deg virtual cockpit As
| if you were inside a booster made from glass.
| creer wrote:
| Wait, that was 5 views no? Facing four fins, plus one fin
| from the front.
| ninetyninenine wrote:
| >The heatshield held out for a much longer time, the asymmetric
| heating on the flaps was interesting. I had guessed that all
| four flaps would have equivalent heating based on an approach
| that was basically that side of the rocket perpendicular to the
| flow but it seems like that isn't the case. Still it seems like
| they are close to having something workable here.
|
| Heat shielding didn't look relevant at this section of the
| flight at all. The booster didn't have any shielding.
| Narishma wrote:
| They're talking here about Starship, not the booster.
| ninetyninenine wrote:
| How does this logically make sense? They said "it looks
| like the heat shield held out".
|
| Where was a heat shield holding out?
| kortilla wrote:
| On starship. Believe it or not, Chuck's comment was about
| both booster and starship
| ninetyninenine wrote:
| And I'm saying he's wrong no heat shield held out to
| anything.
|
| The booster never travelled fast enough to need heat
| shielding ever. Only the starship needs it.
|
| If chuck is talking about both likely he doesn't know
| what he's talking about.
| caconym_ wrote:
| The booster actually does have heat shielding behind the
| engine bells, to protect against aerodynamic heating on the
| return. In some of today's footage you can see it glowing
| yellow.
|
| However, Raptor 3 is supposed to obviate the need for this
| shielding.
| ninetyninenine wrote:
| Where did it glow yellow? What time in the video?
|
| The booster doesn't travel fast enough to need heat
| shielding ever.
|
| It makes zero sense to use heat shielding behind the engine
| bells. Why? Think about it. If the booster renters the
| atmosphere engine bells first the engine bells would burn
| up BEFORE the air even touches the heat shield. If there
| are actually tiles there it's just there to protect the
| booster from the heat of the exhaust.
|
| > However, Raptor 3 is supposed to obviate the need for
| this shielding.
|
| Not completely getting this. So there's a case for the
| booster entering the atmosphere at orbital velocity engine
| bells first? I would think if they did this then THEY want
| the booster to burn up. Anything entering the atmosphere at
| that velocity needs to be made aerodynamically stable as it
| will be traveling faster then the speed of sound. This is
| what causes the heat. If you send something at the speed of
| sound engine bells first that's not stable and is unlikely
| they will do that at all, with or without heat shielding.
|
| I don't think parent knows what he's talking about.
| hrnnnnnn wrote:
| Here's a timestamped link to Scott Manley's commentary
| video where he points out that the yellow glow at the
| bottom of the booster is the heat shielding behind the
| engines.
|
| https://youtu.be/Ysx4t7ICO58?t=550
| caconym_ wrote:
| You ought to do some basic research before making a post
| like this. Honestly might be the most baffling comment
| I've ever seen on HN---what kind of mindset does it take
| to have this kind of overriding confidence in one's own
| lay speculation?
|
| The engine bells are made of different material than
| what's behind them (a material that has to directly
| withstand hot exhaust) and the aerodynamics of the ass
| end of the rocket are complex; some combination of these
| factors means this heating isn't an issue for the bells
| but is a concern for what's behind them. The booster does
| not re-enter from orbital velocity, but does come down
| engines first at supersonic speed. Stability in this
| orientation throughout the descent is a problem SpaceX
| solved with Falcon 9, and SH works the same way.
|
| See the other reply to your comment for timestamped video
| of aerodynamic heating behind the engine bells.
|
| Is it possible you're confusing the booster with the
| second stage (Starship)? They are not the same thing.
| ninetyninenine wrote:
| >You ought to do some basic research before making a post
| like this. Honestly might be the most baffling comment
| I've ever seen on HN---what kind of mindset does it take
| to have this kind of overriding confidence in one's own
| lay speculation?
|
| Don't appreciate this at all. I can be wrong, but there's
| no need to make personal comments on my mindset.
| agar wrote:
| I agree that HN etiquette is generally more polite.
| However, this was in direct response to your comment to
| him/her:
|
| > I don't think parent knows what he's talking about.
|
| We can all do better.
| agar wrote:
| > Where did it glow yellow? What time in the video?
|
| This is a better view than the sibling comment linked.
| It's a greater close-up and you can clearly see the
| yellow glow behind the engine bells. This view is from
| Cosmic Perspective, a partner of Everyday Astronaut,
| whose video is linked:
|
| https://www.youtube.com/live/pIKI7y3DTXk?si=LI4-xQ7UhnvIT
| TiG...
|
| In case you get confused due to lack of context, the
| booster shot is a replay. When Tim goes to split-screen
| view, the right-side image is a live view of the second
| stage ("Starship") as it re-enters from orbital speed. It
| is _not_ a different angle on the booster that is shown
| on the left.
|
| Later commentary explains that the heating behind the
| engine bells is due to atmospheric compression and SpaceX
| specifically orients the drop of the booster to focus
| heating in this spot.
| cpeterso wrote:
| What's the advantage of catching the booster over landing it in
| the ground? Catching it seems like an extra complication.
| bagels wrote:
| You save the mass of the landing systems, you get to have all
| that mass on the ground and not have to lift it into space.
| Dramatically improves the performance of the rocket.
| __d wrote:
| I can speculate ...
|
| I think the primary reason would be that landing legs are
| heavy, and it wastes performance to carry them. If your
| landing mechanism is mostly on the ground, you get that
| performance back.
|
| Secondary reasons might include that it's simpler to get the
| booster right back to the pad. Once things have settled into
| an operational cadence, it's likely feasible to lower and
| lock the booster onto the stool, stack a ship on top, refuel,
| and relaunch -- no more messing around with barges,
| transport, weather issues, etc.
| MPSimmons wrote:
| To my knowledge, you're right, but in reverse order. I
| believe the driving force is time, rather than mass
| overhead, but certainly both play a large part.
| btilly wrote:
| Your primary reason matches what SpaceX themselves have
| said. You either need to be strong enough to handle the
| shock of inpact, or need to spread the impact over time.
| Building either into the rocket adds a lot of mass.
|
| Landing on a device that spreads out the shock moves that
| weight to the static landing platform.
| XorNot wrote:
| It's worth noting that at least 1 Falcon 9 core probably
| got trashed not from the landing, but from rough seas - so
| cutting out the ground logistics chain adds resiliency.
| Gare wrote:
| Falcon 9 can land on land just fine (and it was done
| multiple times on less demanding missions). Landing on
| barge gives it extra performance.
| wcoenen wrote:
| The rocket equation implies that if you want to maximize the
| delta-v a rocket gets out of a certain amount of fuel, then
| you should get the dry mass as close to zero as possible.
| Eliminating landing legs helps a lot.
| _dain_ wrote:
| Why send the landing mechanism to space when it isn't needed
| there? Whatever kit you put on a rocket has to be brutally
| miniaturized to limit how much you eat into the payload mass.
| Also has to be rugged enough to withstand tremendous
| vibrations and thermal stresses. That adds cost and more
| points of failure. You want to move as much of the complexity
| off the rocket as possible. Then doesn't matter if the
| catching mechanism on the launch tower is big and heavy.
| deelowe wrote:
| I thought it was so they can name make the booster body
| thinner relying more on the fuel for structural rigidity.
| syncsynchalt wrote:
| 1) legs are heavy 2) empty rockets are stronger in tension
| than compression 3) the booster is large enough to make (1)
| and (2) matter more than they did for Falcon 9.
| boxed wrote:
| The reflected sound of the engines is enough to destroy the
| engines, ironically. That's also why the launch mount is so
| high. You'd need truly enormous legs, which wouldn't work for
| weight.
| m4rtink wrote:
| The load for landing and almost empty booster would be
| less, but otherwise yes, it would be much more than the
| single Merlin engine on the Falcon 9, with all associated
| issues (local scorching/spalling of the pad, acoustic
| issues, extra weight, longer turnaround, etc.).
| rkagerer wrote:
| _Seems like it adds a lot of risk_
|
| I'm actually wondering about that. If I understand correctly,
| the arms can move up and down, and pivot around the tower. This
| allows them to correct for some error in the rocket trajectory
| and also (presumably) "soften" the final contact. Between the
| nozzles and the arms, it gives SpaceX a lot of degrees of
| freedom in the final seconds (you can see how the booster kind
| of "hovered" right at the end) and in certain respects might
| even offer more forgiveness than the hard ground.
|
| Could it smash into the tower? For sure. Would that be more
| dangerous than smashing into the pad? I don't know.
|
| It's a new technique with which we don't have a lot of
| experience.
| ChuckMcM wrote:
| My thought (admittedly not well developed) is that smashing
| into a landing pad of concrete can damage that pad but it can
| be quickly repaired without affecting the ability to launch
| future rockets. If you damage the launch tower significantly
| you're going to have to suspend launches from it until you
| fix it. So the "higher risk" is more critical assets offline
| in the event of a non-optimal return.
| rkagerer wrote:
| Understood, although weren't they out of commission for a
| really long time anyway the last time they damaged their
| launchpad?
| pfdietz wrote:
| That was a launch pad, not a recovery pad. The launch pad
| has to be engineered to survive full thrust from all the
| engines, and for a rather long time as the loaded vehicle
| accelerates upward.
| rkagerer wrote:
| Thanks for clarifying!
| ocdtrekkie wrote:
| Apparently they are heavily investing in having multiple
| towers ready to go to be able to do multiple successive
| launches. Presumably with that approach, one being damaged
| for a while will be annoying but not project-stopping.
| creer wrote:
| There are already 2 launch towers (2nd one not quite
| complete but getting there.)
| creer wrote:
| Heh Plus one at Kennedy in Florida, LC-39A
| generuso wrote:
| It helps enormously that unlike Falcon-9 this rocket can dial
| down the thrust of its engines low enough to be able to
| actually hover or to move arbitrarily slowly in the final
| meters before touchdown.
|
| It can arrive to the designated intermediate point with some
| already good accuracy, and then take some time to trim the
| remaining errors to the noise level more slowly, possibly
| with feedback from the ground sensors.
|
| The chopsticks also include rails with shock absorbers, the
| action of which can be seen in the view from the tower during
| the landing [1], so the required accuracy is probably
| relatively modest, provided one plans the maneuver carefully.
|
| [1] https://youtu.be/Ysx4t7ICO58?t=678
| TechDebtDevin wrote:
| The main takeaway from Scott's commentary is that the
| chopsticks allow the ommission of landing legs and all
| their subsequent systems and saves a ton of weight. The
| added risk to dial this technique in is likely worth it in
| the long run from a sustainability stand point.
| kibwen wrote:
| Except that the landing legs allow you to land anywhere
| with a flat pad of concrete, whereas this requires
| comparatively enormous infrastructure investment.
| sagarm wrote:
| You'd still have to recover the rocket. I imagine the
| number of places you could land and economically recover
| the rocket is pretty small.
| swagasaurus-rex wrote:
| unless it can be refueled from a truck and reused without
| inspection.
| ang_cire wrote:
| That is so many iterations in the future, it's not really
| meaningful to design for now.
| m4rtink wrote:
| Super Heavy and its 33 raptor engines really needs a
| specific launch pad - on the first launch they tried to
| see what happens when they just fire it over a regular
| concrete slab (but still way above in a launch mount) and
| ended up with a massive crater. While Starship might be
| able to hop from unimproved landing sites, that is not
| really an option for Super Heavy, even with low fuel and
| short hops IMHO.
| cma wrote:
| That's why it is good in the long run, assuming the
| infrastructure can't get annihilated in a crash.
| Cthulhu_ wrote:
| There's always a risk, but at the same time, they've
| designed the infra now, they can rebuild it from the
| plans (and iterate on any flaws). There's a (imo
| unnecessary) idea of doing a lot of launches, for which
| you'd need multiple liftoff and landing sites.
| JacobThreeThree wrote:
| >comparatively enormous infrastructure investment Any
| infrastructure that can remain on the ground and doesn't
| have to be on the rocket is worth whatever the investment
| cost.
| avmich wrote:
| You note of course that instead of legs, which have mass
| and have to have a structure in the stage which
| distributes the loads the SH has those parts with pins
| which were locked eventually with Mechazilla's arms, and
| those parts also have mass and need to have corresponding
| distribution of loads.
|
| How different those consoles with pins are from possible
| landing legs, and how much savings they provide is an
| interesting question. It's quite possible they provide
| some savings - but it would be nice to know some details.
| tempestn wrote:
| It seems pretty likely that those pins are going to save
| considerable mass and volume compared to articulating
| landing legs.
| avmich wrote:
| Why so? Pin parts need to withstand similar loads - and
| if amortizing rails of Mechazilla may soften the contact,
| the direction of loads for pin parts is less favorable
| than for legs. Legs don't need to be big or too numerous
| - effectively legs are those pin parts moved to the
| engine compartment and turned for an angle.
| krisoft wrote:
| Because the pins can be much shorter. Take a look at the
| falcon 9 legs. They are enermous both in absolute terms
| and relative to the whole rocket. They need to be that
| long to provide a stable platform and enough clearance
| for the nozzles and the residual plume as the engines
| shut down.
| inglor_cz wrote:
| Not just that. Landing legs need to actuate, which means
| having actuators - another part that can fail. Pins are
| just dumb bits of steel.
|
| IIRC at least one returning Falcon 9 stage was lost to a
| landing leg collapsing.
| dotancohen wrote:
| Don't forget that between certification and catch attempt
| that catching infrastructure is subject to the launch of
| the most powerful rocket man has ever created. It seems
| that the consideration about another part to fail is not
| valid here as the parts to fail have not disappeared but
| rather moved to the tower. They could still fail - in
| fact it seems that there are now many more recovery-
| critical parts.
|
| That is, unless the falling rocket could abort a tower
| catch and move to a secondary nearby tower if a failure
| is detected in time.
| rbanffy wrote:
| > and move to a secondary nearby tower if a failure is
| detected in time.
|
| They will have a tower in the Cape. It's conceivable they
| could land there depending on return trajectory and save
| some mass for payload with that maneuver. I am also quite
| sure they will be a dozen towers in Boca Chica and I
| wouldn't be surprised if they build a couple in
| California for Southward launches.
| inglor_cz wrote:
| I think it is very much valid if the entire context is
| taken into account.
|
| The tower is used for various stacking and craning
| operations between launches. There is a better chance to
| detect any developing anomalies outside the launch
| context.
|
| Also, being on Earth and flying nowhere, it can be
| sturdier and heavier than any flight hardware. Much like
| Roman aqueducts, it can be overbuilt a bit to ensure some
| extra resilience.
|
| Plus, more towers at the same site, as you say. If one
| malfunctions, another one can act as a backup. In
| contrast, every single landing leg is a mission-critical
| component and cannot be replaced in-flight by another
| one.
| rkagerer wrote:
| They do checks of the tower systems before using it, and
| have abort contingencies in case something goes wrong
| during final approach. I'm not sure if they intend (or
| have fuel budget) for last-second aborts to other towers,
| or if they just ditch in the ocean (remember there are no
| humans on the booster).
|
| I'm curious how late in the catch sequence they can still
| abort.
| Veedrac wrote:
| Compression and tension are quite different loads. There
| have been rockets in history that would collapse under
| their own weight unpressurized. Neutron's second stage is
| a hung tank for similar reasons. Bucking is a pain. Super
| Heavy can obviously support its own weight, but tension
| is always going to be the easier load path.
| IneffablePigeon wrote:
| The booster needs lift points anyway for manufacturing
| and moving it to the launch mount. You can't engineer
| those out, really.
| kibwen wrote:
| This seems a bit like removing landing gear from aircraft
| and telling airports to shoulder the added cost of
| accommodating them. You've simply shifted complexity
| elsewhere. I understand that people are dazzle-eyed over
| the science fiction appeal, but IMO this feels like a
| distraction. The rocket's already reusable and already
| the largest rocket ever built, this doesn't add any
| fundamentally new operational capability while also
| burning a lot of engineering cycles and adding complexity
| and uncertainty.
| soulofmischief wrote:
| What you're missing is the rocket equation. The less
| weight, the less fuel you need and the larger your
| payload. We should trust the decisions of these
| experienced engineers who are deeply familiar with the
| tradeoffs involved in spaceflight more than our own
| intuition.
| pfdietz wrote:
| Removing unnecessary systems that have mass is a big part
| of making reusable rockets work. It's why propulsive
| landing is superior to landing with wings, for example.
| lupusreal wrote:
| What you're describing with airplanes already happened.
| Large airplanes used to land on the water, which incurred
| a mass and aerodynamic penalty for the airplane but was
| very cheap to operate airfields ("fields"?) for; it only
| required a flat lake or harbor which was already there.
| The switch to landing gear allowed airplanes to be more
| optimized but requires more infrastructure expenditure
| for large aircraft.
| inglor_cz wrote:
| Not a distraction at all.
|
| It is not just about shift of complexity from A and B.
| Anything that stays on Earth permanently can be built
| without particular regard to its weight, e.g. much
| stronger, much more resilient, with bigger safety factors
| etc.
|
| With any flight hardware, you need to make painful
| tradeoffs between reliability/sturdiness and weight.
|
| If anything out of the ordinary happens, massive steel
| chopsticks can take a lot more strain than a landing leg
| which needs to be carried to the edge of space and back.
| jessriedel wrote:
| The booster is always returning to the general vicinity
| of the launch tower (either the tower itself or a barge).
| It isn't used anywhere unimproved, and in particular is
| not used on Mars. So what scenario would it be helpful to
| be able to land the booster on a flat concrete pad?
| Cthulhu_ wrote:
| It sounds like sci-fi thinking tbh, but at the same time,
| Musk has hinted at using rockets for intercontinental
| travel. But even then, it wouldn't be just a concrete
| pad, it'd need disaster recovery systems and
| infrastructure in place.
| Tepix wrote:
| You're talking about Starship, not the booster.
|
| Starship will get landing legs.
| nkoren wrote:
| Only for Moon & Mars landings. The plan is to use the
| catch tower, Same as the booster, when landing on Earth.
| mavhc wrote:
| Just build another tower, like you build another airport
| jfoster wrote:
| Not just a hint. Here's a 2 minute video produced by
| SpaceX called "Earth to Earth".
|
| https://www.youtube.com/watch?v=zqE-ultsWt0
| jessriedel wrote:
| The booster does not travel more than ~50 miles.
| starspangled wrote:
| The first stage doesn't really need to land anywhere, it
| launches from a known location that already has a
| comparatively enormous infrastructure investment.
|
| The second stage might want to land in other places. Not
| as a satellite launching bus or fuel truck though, that
| just wants to go up and down in an uncomplicated and
| unsurprising way, and that's where the vast majority of
| their launches will come from.
|
| For inter-planetary missions yes, but they have different
| second stage designs for those that aren't made for tower
| landings. If it gets used as a military transport, then
| similarly it will be a different second stage design.
| echelon wrote:
| The military transport option is going to provide so much
| capital.
|
| It's the C5 Galaxy, but with only a couple of hours
| needed to deploy into any theater in the world.
| Gravityloss wrote:
| There's some work needed to have the launch flexibility
| though. Ie lead time to launch, multiple launch
| locations.
|
| In comparison, simplified, if you have a bunch of things
| you need to send somewhere, you can go to the nearest
| airstrip and call a bunch of C5:s from somewhere a couple
| of hours away.
| adastra22 wrote:
| If we're talking about sending equipment / supplies, you
| can prelaunch into orbit and then re-enter on demand.
| Gravityloss wrote:
| That could actually probably be worse as the orbital path
| would not likely go near the wanted landing site,
| potentially in days. And anyway how do you know in
| advance what you are going to need (if it's not a nuke)?
|
| Instead, with a near-future rocket, you could have some
| sort of assortment of "most likely stuff needed" stored
| near a launch site and be ready to pack and launch in an
| hour.
| baq wrote:
| The starship can use the atmosphere to change its orbit.
|
| The capability hasn't been tested but why wouldn't it
| work if it works on a x-37?
| adastra22 wrote:
| It's called cross-range capability, and yes Shuttle was
| able to do this (albeit for different reasons).
| bryanlarsen wrote:
| Starship has a lot less cross-range capability than X-37.
| Gravityloss wrote:
| Exactly. Cross-range capability is expensive mass wise.
| X-37 is very heavy for its payload, as was the Space
| Shuttle.
| adastra22 wrote:
| https://fastcompanyme.com/technology/this-startup-has-a-
| plan...
| pmontra wrote:
| With maybe totally different requirements on the G forces
| and vibrations that the equipment and people inside a
| Starship must withstand compared to flying. Not
| necessarily all the existing equipment can survive a
| Starship launch and not necessarily all military
| personnel can fly in a rocket. Of course they can select
| the personnel, like they do select paratroopers. Fixing
| the equipment or developing new one might be costly.
| Workaccount2 wrote:
| Thankfully, military stuff that is field deployed
| typically already has insane shock and vibration
| requirements. We build military stuff at our facility and
| it all has to go through lots of shock, vibration, and
| temperature testing. The military _really_ wants to be
| sure things don 't fail on the battlefield (which could
| also be aptly called "the-shock-and-vibration-field")
| qzw wrote:
| Just want to add that a lot of military equipment is
| already designed to be airdropped in addition to any
| other expected battlefield stresses, so they're probably
| some of the best candidates for rocket transport in
| existence.
| boxed wrote:
| Landing legs are out of the question for Super Heavy
| anyway. If the engines come that close to the ground, the
| reflected sound from the ground will tear the engines
| apart.
| ayewo wrote:
| That's fascinating!
|
| Do you have a source for this where I can read more?
| bitwidget wrote:
| The 3 RS-25 (1860 kN each)[1] used for the Space Shuttles
| had 300,000 Gallons of water output per 41 seconds [2]
| when it launched. On landing, the Falcon Super Heavy used
| 5 or so [3] of the Raptor Engines (2750 kN each [4]). I'm
| making a few assumptions based on Napkin Math, but the
| parent comment seems about right since the engineering
| required (and the payload weight lost due to the
| weight/space requirements of landing feet for the FSH),
| would be too high to withstand the vibration reflection
| of landing on solid landing pad.
|
| [1]https://en.wikipedia.org/wiki/RS-25
|
| [2]https://en.wikipedia.org/wiki/Sound_suppression_system
| #NASA
| [3]https://www.youtube.com/watch?v=pIKI7y3DTXk&t=6850s
|
| [4]https://www.spacex.com/vehicles/starship/
| restalis wrote:
| To me, it's not risk reduction that they're after with that
| booster catching mechanism, but weight reduction. Those
| landing legs that we've seen before (and the mechanism
| related to them) are costly weight that is absolutely
| necessary only on the rocket itself, because that is expected
| to land on its own somewhere on a bare rock. For booster
| however, it makes sense to have as much of such launch and
| landing weights externalized, considering booster's reduced
| use-case of starting from a spaceport and very soon ending up
| back there too.
| thot_experiment wrote:
| The way the trajectory is designed is that it has to scoot
| over to the tower at the last second, and it only does that
| if it's really really sure it can make it, otherwise it
| crashes off to the side.
| db48x wrote:
| A good explanation of how it works, from before the catch:
| https://www.youtube.com/watch?v=ub6HdADut50
| JoachimS wrote:
| Yes, we should probably assume that the SpaceX engineers have
| considered all of the risks HN readers are able to come up
| with in a few hours. And that they have evaluated
| alternatives like the added weight etc of having foldable
| legs on the booster.
|
| The catchzilla solution is an example of their amazing
| ability to think out of the box. This solution, and things
| like the rapid evolution of the Raptor engine (see picture,
| story here: https://medium.com/@futurespaceworld/the-
| evolution-of-spacex...), dynamic engine configuration (33,
| 13, 3, zero, up again) and control is almost magically
| impressive. This is the stuff of Sci-Fi, brought to life.
| sha16 wrote:
| But did they consider a giant spider web?
| JoachimS wrote:
| We can probably assume yes:
| https://www.youtube.com/watch?v=qz7Eb8WiiWA
| potato3732842 wrote:
| >The 'chopsticks catch' was amazing to watch. Seems like it
| adds a lot of risk and clearly the booster needs additional
| fire suppression systems :-) perhaps the tower could mount
| something that sprays the booster like the barges have for the
| F9 boosters.
|
| There's no reason to reinvent the airport firetruck.
| kortilla wrote:
| The airport fire truck can't control fires 250ft in the air
| potato3732842 wrote:
| It's pushing the limits but it's close enough to existing
| capability to be a pretty easy ask.
| CydeWeys wrote:
| Unless you're gonna make it fully automated, it's not gonna
| work here as it can't be within kilometers of the landing
| site during landing in case there's a catastrophic failure.
| nine_k wrote:
| > _no reason to reinvent the airport firetruck._
|
| There is. The booster is high above, and is larger than
| basically any aircraft. There's no flat concrete airfield
| around either.
|
| I would suggest blowing CO2 or nitrogen through pipes
| positioned at the right height on the tower.
| adastra22 wrote:
| It's not going to burn like that in production.
| Cthulhu_ wrote:
| Why would you use a firetruck if you could also run a hose up
| the tower and get it right where it's needed?
| Jugurtha wrote:
| I'm wondering if they'll be using the vertical equivalent of
| arresting gear on aircraft carriers[0]. See when fighter jets
| land on aircraft carriers? There's a cable that decelerates
| them. That, but for vertical landing.
|
| The way these chopsticks are set forces the booster into a
| dangerous, snake like maneuver (a SnakeX maneuver) at the last
| second from a vertical setting, to get into the chopsticks.
| This maneuver is due to the fact chopsticks are short and the
| booster has to land on one point in space. No degrees of
| freedom.
|
| Now, imagine if the chopsticks were long. The booster wouldn't
| have to land at one specific point, but it could now land on a
| line. One degree of freedom.
|
| Now replace the long chopsticks with cables, and then add
| another pair of cables perpendicular to them. So you have a
| pair of parallel cables perpendicular to a second pair of
| parallel cables. Now the booster doesn't have to land on a
| _line_ , but can land anywhere in the grid that's covered by
| the cables. Two degrees of freedom.
|
| Pushing this thought leads to having a sort of iris diaphragm,
| like the ones in optics, but an iris diaphragm of cables. The
| diaphragm is open when the booster is about to land, then
| closes in quickly. Imagine this[1], but it's cables cinching
| in.
|
| Now, it's a diaphragm of cables, not a diaphragm of rigid
| beams, so I imagine the deceleration to be even smoother as the
| cables elongate, and an additional system of springs and
| dampers to counter the weight of the booster.
|
| The booster is vertical and stays vertical. Granted, an
| unstable equilibrium, but it beats doing the SnakeX maneuver to
| get to the chopsticks, and that's another story.
|
| Now, imagine the iris cable diaphragm can move up and down like
| equipment handling containers, and now you have _three degrees
| of freedom_. That 's less control to worry about on the
| booster's side at the worst possible moment, landing, where you
| can't make adjustments anymore.
|
| This not only means being more forgiving on mistakes related to
| position, but also on speed _and_ angle. The diaphragm catches
| the booster at any angle, and given that it cinches way above
| the center of gravity, the booster goes back to a more stable
| vertical position.
|
| For the fire, maybe you just need a big hole down there.
|
| - [0]: https://en.wikipedia.org/wiki/Arresting_gear
|
| - [1]: https://en.wikipedia.org/wiki/File:Iris_Diaphragm.gif
| jve wrote:
| SpaceX likes to simplify and not to complexify things. And
| they demonstrated they can do landing accurately.
|
| Moreover I think Elon discusses the mechazilla arms in one of
| Tim Dodd interviews. They dont want longer arms, ratger
| shoeter.
|
| Think about physics involved for longer arms and how much
| more stress you will putt on the connection points.
| Jugurtha wrote:
| > _SpaceX likes to simplify and not to complexify things.
| And they demonstrated they can do landing accurately._
|
| Yes. Something falling into a web of cables. I'd say it may
| be simpler than optimally controlling that last SnakeX
| maneuver to be hugged by a short-armed T-Rex.
|
| > _Think about physics involved for longer arms and how
| much more stress you will putt on the connection points._
|
| That's why I wasn't talking about arms, but _cables_ , as
| explained by most of the reply.
| jve wrote:
| Good luck not ruining rocket with that cable web. Now you
| got other problems to target into some cell. Moreover
| cables could be lingering depending on thrust. Or maybe
| thrust will just cut em easily.
| Jugurtha wrote:
| > _Good luck not ruining rocket with that cable web._
|
| What do you mean?
|
| > _Now you got other problems to target into some cell.
| Moreover cables could be lingering depending on thrust.
| Or maybe thrust will just cut em easily._
|
| It's an iris diaphragm that's open but cinches on the
| booster.
| Faaak wrote:
| Did you think about how you support the cables ? Surely
| they must be tensionned or else they will hang. How do
| you tension them ? Of course you know that the more the
| cable is tensionned, the more force you need. So you need
| a big-ass structure to hold all of these cables. They
| must be able to circulate around the perimeter, while
| being in tension, while not collapsing the structure that
| holds them, etc..
|
| I'm sure you think it's easy, but I'm sure some people
| thought a bit more
| Jugurtha wrote:
| > _Did you think about how you support the cables ?
| Surely they must be tensionned or else they will hang.
| How do you tension them ?_
|
| Mechanical advantage. The booster weighs 250 tons. A 40'
| shipping container has a max payload of about 30 tons.
| There are cranes that can lift 250 tons, and it won't be
| one, but many. Have you seen gantry cranes?
|
| > _So you need a big-ass structure to hold all of these
| cables._
|
| Similar to the big-ass structure holding the 250 ton
| booster with the T-Rex arms?
|
| > _They must be able to circulate around the perimeter,
| while being in tension, while not collapsing the
| structure that holds them, etc.._
|
| Not circulate, but translate. The cinching in is a result
| of them translating. Again, see cranes and gantry cranes.
| Or, just see the actual chopsticks: circulating, not
| collapsing the structure that holds them, _while being in
| tension_ , holding the booster at the free end.
|
| Are you seeing the shear and moment diagram of that
| cantilever beam with point load? (I know, it's an
| extension of a supported beam, but still cantilever).
|
| > _I 'm sure you think it's easy_
|
| I'm not sure I think it's easy, I can't see how you're
| more sure than I about my own thoughts.
|
| > _but I 'm sure some people thought a bit more_
|
| You are people, too. Nothing prevents you from thinking
| as well, if for nothing than to have a civil conversation
| on a forum.
|
| Now, that's all fun. Imagine they keep it the way it is,
| but they duplicate the setting to make a circle, so the
| booster lands in the middle of many chopsticks... What do
| you think about that?
| jve wrote:
| > so the booster lands in the middle of many
| chopsticks...
|
| And how exactly this requires less precision? I see
| multiple issues:
|
| - No way to escape/last second abort away from tower once
| you dipped into that net.
|
| - The booster arms must be longer/heavier, the tower
| support structure need to support more weight.
|
| - Cables have a lot less thermal mass than the tower/arms
| - if the torch coming out of raptor engines will touch
| the cable, it may either cut or soften the cables and
| they will behave in a different way.
|
| I mean we could have had this discussion previously but
| now they demonstrated on the first try that they can
| catch the booster... why bother?
| Jugurtha wrote:
| > _I mean we could have had this discussion previously
| but now they demonstrated on the first try that they can
| catch the booster... why bother?_
|
| Because these things must work every time, not just the
| first time. Because why not talk about it, it's an
| interesting topic and musing about it is amusing. Because
| it's not a bother. I'm surprised one needs a reason, but
| here are three already.
| Faaak wrote:
| The crane lifts on the same axis as gravity, so the force
| is the same as the object. If the cable is horizontal-ish
| the the force is X/cos(a), which can be many times higher
| than the object
| Jugurtha wrote:
| https://en.wikipedia.org/wiki/Mechanical_advantage
|
| https://en.wikipedia.org/wiki/Crane_(machine)
|
| https://archive.org/details/constructioncra00markgoog
| Cthulhu_ wrote:
| This is a solution for a problem that's already solved, that
| is, booster maneuverability and accuracy. But they've just
| demonstrated that the booster is accurate and controlled
| enough to land on the chopsticks, and they have over a decade
| of experience in making rockets land accurately in a specific
| zone.
| nkoren wrote:
| Next year, China says it will be testing a concept very
| similar to what you've described, with its Long March 10A
| rocket:
|
| https://www.youtube.com/watch?v=27TvGDpPLNw
|
| It will be interesting to see how these two approaches fare
| vs. one another.
| Jugurtha wrote:
| That's _exactly_ it, thank you! What worries me with the
| current one that landed is the gradient: because the arms
| are short and the spot is tight, the burden is on the
| booster to make very sharp corrections (especially on
| pitch) to get caught when there 's literally a few meters
| left, with an increased risk at the worst time (no
| altitude, and structures around), as opposed to leaving the
| pitch as is and landing vertically. In other words: the
| possibility to screw a perfect launch by introducing
| irremediable risk in the last few seconds and meters.
|
| Then again, I just watched the launch and that was the
| first thing that popped into my mind, and the first
| "design" that popped into my mind as I was replying to the
| thread, so not much thought went into it.
| tvier wrote:
| One thing to note is that the "Snake" maneuver was designed
| to keep the tower safe during the test, and not forced on the
| rocket by the chopsticks.
|
| The rocket was set to come down on the pad just in front on
| the tower and launch mount until the final 3-engine landing
| burn started. This kept the infrastructure safe until the
| last moment, but also required that lateral translation you
| referred to.
| T-A wrote:
| That's how the Chinese are planning to do it:
|
| https://youtu.be/OYWBmu6H0ik?feature=shared&t=35
| mhandley wrote:
| As to whether catching the booster adds risk - I'm not sure it
| does.
|
| First, to the extent the booster is out of position in the x
| (sideways) direction, the chopsticks can move to accomodate
| error. But actually I think this dimension is the easiest of
| the three, as the booster has plenty to time to null any error
| in this dimension.
|
| In the y direction (direction of travel towards the tower), the
| rails on the chopsticks can cope with the booster touching down
| along quite a long distance. But importantly, they appear to be
| smooth, so the pins can initially skid along them and then the
| booster can swing if it has not fully nulled any horizontal
| movement. In contrast, if the booster used legs and has not yet
| fully nulled any horizontal motion at touchdown, there is a
| greater risk of breaking a leg or simply tipping over.
|
| And in the z direction, it should be possible for the
| chopsticks can absorb more vertical motion than legs can
| absorb, because you can easily build in huge
| springs/dampers/etc into the ground equipment without concern
| about mass.
|
| Catching also puts the booster in tension rather than
| compression - it's easier to be rigid in tension than
| compression.
|
| Finally, if legs were used, the engines would have to get close
| to the ground during landing, so reflected shock from the
| ground could cause damage. I know Falcon 9 does this, but the
| area of the base of Starship is much greater, so there's
| effectively less room for the reflected energy to escape.
| Catching completely removes this risk.
|
| On balance, I think they would have better chance of success
| for each mission by catching. The main downside would be if you
| fail to catch, you may need to build a new tower, whereas a
| flat pad would be cheaper and easier to repair.
| consumer451 wrote:
| I am really curious what the maximum wind speed allowed for a
| booster landing will be. Upon landing, it has a lot of
| windage and not nearly as much mass as during take-off.
|
| I have experience with docking large boats and it does seem
| to be a bit similar. In the case of boats, wind is a big
| deal, and the booster has nothing "below the waterline" to
| slow down the effects of wind.
| margalabargala wrote:
| I doubt this is an issue.
|
| Not because wind wouldn't affect an empty booster; it
| certainly would.
|
| But since the booster returns within 8 minutes of the
| launch, the weather in which a booster lands is restricted
| to the weather in which they will launch a rocket.
| consumer451 wrote:
| But then wouldn't the limiting factor for launch be the
| maximum allowed wind for landing?
| daveguy wrote:
| The value of what is going up (which includes the
| booster) will be greater than the value of the empty
| booster. Factors of safety would be based on the launch
| rather than the catch. In other words, if it's deemed
| safe to launch the calculation for safe to land is easier
| to pass. Especially when you are taking passengers on
| launch. Wind is already a significant factor in launch.
| mhandley wrote:
| That's true, except it neglects the cost of the launch
| tower itself. If you botch a catch and need to rebuild
| the launch tower, that could get very expensive, both in
| immediate costs of rebuild, plus in opportunity cost of
| missed launches. So in the end, whichever has the lowest
| wind limit, launch or landing, will likely determine
| whether they fly.
| daveguy wrote:
| Ah, excellent point! They wouldn't ignore one hazard
| because another is less severe. And you are correct, I
| wasn't considering hazards to the launch tower itself. I
| think you are absolutely right, either would cause a
| flight to be scrubbed. I wonder if the two wind limits
| would be different.
| psunavy03 wrote:
| This is often the case with airplanes; it's not a new
| concept.
| consumer451 wrote:
| Definitely not, and I am not trying to be a doomsayer
| here. It's just interesting. Now that I think about it
| more, I believe a Falcon 9 Starlink launch was once
| delayed due to weather conditions at the drone ship.
| ro_bit wrote:
| The catch looks amazing, but one thing I don't understand is why
| SpaceX needs the technology to catch a booster they've already
| demonstrated the ability to land boosters on barges. Is the arm
| more cost effective to scale compared to a barge?
| mlyle wrote:
| The argument is that you don't need to spend the vehicle mass
| on legs, so you get performance.
|
| On the other hand, I imagine you could wipe out any benefits to
| $/mass launched pretty quickly by blowing up the tower.
| msk-lywenn wrote:
| Maybe the goal is to refill and relaunch immediately?
| slashdave wrote:
| This. You can lower the rocket back on the launch base,
| refill, and launch again within hours.
| cubefox wrote:
| After checking if everything is okay with the vehicle. And
| of course the government agencies must determine that
| frequent sonic booms (there is one per booster landing) are
| acceptable for the public.
| valine wrote:
| The landing legs are heavy. SpaceX would rather have more
| payload than carry legs to space on every launch.
|
| Also landing on the launch pad means you don't have to
| transport the rocket. Just have the arms set it down and you're
| ready to launch again.
| _djo_ wrote:
| This booster is much, much larger than the Falcon 9 first
| stages that land on barges. It's ~70 metres high, versus ~40
| metres for the Falcon 9 first stage, and weighs about 275 000
| kg compared to the ~20 000 kg of the Falcon 9 first stage.
|
| In short, it would require such huge and heavy landing legs and
| landing barges that it probably wouldn't be feasible.
| mock-possum wrote:
| Holy shit I didn't realize it's an order of magnitude heavier
| db48x wrote:
| https://www.reddit.com/r/space/comments/exvu55/size_compari
| s... https://www.visualcapitalist.com/comparing-the-size-
| of-the-w...
| stetrain wrote:
| FYI that first link is showing a previous, larger,
| concept iteration of Starship (then known as ITS) which
| would have had a 12m diameter, versus the 9m version that
| SpaceX ended up building.
|
| The second link seems to show a version of Starship
| that's relatively up-to-date.
| db48x wrote:
| Yup. Someone should make a new graphic.
| migueloller wrote:
| The square-cube law strikes again!
|
| https://en.m.wikipedia.org/wiki/Square%E2%80%93cube_law
| cryptonector wrote:
| Weight. Legs weigh a lot. That's dead weight for a launch
| system, and it serves only to reduce payload to orbit.
|
| For Falcon 9 that's not that big a deal because they're NOT
| trying to reuse the second stage. Whereas with Starship they
| need more fuel to recover the ship, and that means they need to
| save weight elsewhere to avoid losing too much payload to
| orbit.
| iamcreasy wrote:
| SpaceX is also not very happy with the pair of forward flaps
| and 10 ton thermal protection needed as control surface and
| re-entry.
| db48x wrote:
| It takes time for the barges to return the booster to the
| launch pad. They want to be able to launch Starship, have the
| booster land back at the launch pad, have the arms set it back
| down on the ground, and recycle the booster for another launch
| in just a few hours. Then the arms can be used to stack the
| booster and the next payload on the launch platform.
| gramie wrote:
| When I was visiting the space center in Huntsville, Indiana, I
| had a chance to talk with one of the volunteers. His name was
| Brooks Moore (https://www.youtube.com/watch?v=O3hudRA3yL8), and
| he had been the director of navigation systems for the Apollo
| (and other) projects.
|
| The first SpaceX barge landing had just taken place, and I asked
| him what he thought. He got a faraway look in his eyes, and
| agreed that it had been spectacular. For those guys, it must have
| seemed like all of their dreams were coming true.
| robbiet480 wrote:
| I believe you meant Huntsville, Alabama?
| atlgator wrote:
| Nothing short of inspiring. Moving humanity forward. Well done to
| the SpaceX team.
| ramshanker wrote:
| Ok. I will admit this. SpaceX Engineering is making me feel
| regret for not choosing Aerospace Engineering back in Undergrad.
| Oh well, That Tower is almost within Civil-Structural
| Engineering.
| cubefox wrote:
| Here is Scott Manley's summary and analysis of flight 5:
|
| https://youtube.com/watch?v=Ysx4t7ICO58
| Yacovlewis wrote:
| People on earth are experiencing the Jetsons and the Flinstones
| at the same time
| 1shooner wrote:
| This is what makes it bittersweet. So many comments here
| talking about this being progress for 'humanity'. I may be
| cynical, but most of humanity will get no benefit from any of
| these accomplishments. This is technology owned by and
| ultimately in service of a minuscule fraction of humanity.
| altcognito wrote:
| The launching of Starlink will absolutely improve the quality
| of internet to underserved countries and rural areas. Quality
| internet is a game changer.
| Yacovlewis wrote:
| Agreed. Even if it takes a long time for us to be riding
| rocket ships to visit our grandparents, we'll be benefiting
| from this technology way faster than that
| lurking_swe wrote:
| better weather forecasting (launching and replacing the
| existing old satellites) seems useful. starlink has already
| been a game changer in communities experiencing natural
| disasters and is now coming to commercial airplanes.
|
| so there's something at least. :)
| grecy wrote:
| Driving around Africa basically every village had solar
| panels, a huge number of people had smart phones and
| internet.
|
| The least developed country on earth is currently developing
| faster than any country ever has at any time in history.
|
| Read the book "factfullness"
| mk_stjames wrote:
| Food for thought:
|
| Maybe 'the Jetsons' and 'the Flintstones' aren't as far apart
| as we think, us being people who like to think we are
| witnessing 'the Jetsons' now. Maybe that is just a relevant
| distinction.
|
| Maybe those two descriptors are much closer than they would
| appear to some outside observers. Maybe it's really just
| 'Flintstones part 1;' and 'Flintstones part 2', right now.
|
| Or...
|
| Our 'Flintstones' was already 'Jetsons' compared to everything
| else in this observable universe, which winds up mostly being
| just peat bogs on Dagobah, comparatively, and we're just
| inching out the icing on the cake at this point.
|
| Who knows.
| Yacovlewis wrote:
| Based on this conversation, how many of y'all are actual rocket
| scientists? I'm blown away by the expertise in some of these
| comments
| aksss wrote:
| And here I was blown away by the ignorance of many of the
| questions. Why no landing legs? Why is this more impressive
| than the other rocket landings? What's the thingy that fell off
| during separation? Sometimes I need to remind myself that other
| people have lives, I guess. XD
| robotnikman wrote:
| The engineers at spaceX are amazing, and I'll admit I envy their
| tenacity and genius.
|
| The amount of progress we have seen in rocketry and space travel
| in the last decade is mind blowing, I never thought I would see
| this in my lifetime.
|
| Edit: Decided to give it a shot and applied for a backend
| software engineering position at SpaceX. I'm not sure if it will
| be noticed, but its worth a shot. I may not be a rocket
| scientist, but it would be great to contribute using the
| knowledge I do have.
| supportengineer wrote:
| We could have had this all along.
| ceejayoz wrote:
| Eh, maybe. There's a lot of computing and telemetry going on
| that benefits from the last twenty years of miniaturization
| and performance. The iPhone seemed impossible when announced
| to BlackBerry; tech has gone crazy fast.
| collinmanderson wrote:
| It's a lot easier to model and simulate too.
| Teever wrote:
| You should take a look at what Von Braun was planning for
| the Saturn V by the mid 1970s.
|
| IIRC they were talking about 100+ Apollo launches to get a
| real space station, moon base, and expedition missions to
| Mars by 1980 and with that would have come a real drive to
| innovate and improve on the Saturn V.
|
| Without the computational power that we take for granted
| today they would have definitely brute forced their way to
| elegant solutions and got somewhere close to where we are
| by the mid 90s.
|
| This would have lead to tremendous innovations in solar
| panels, batteries, and metallurgy much sooner than we ended
| up getting to them.
|
| Instead we chose a different path and made ourselves
| completely dependent on oil.
| ceejayoz wrote:
| A lot of those plans were just plain goofy. The Shuttle
| was supposed to generate the same sort of awesomeness,
| too.
| Teever wrote:
| Apollo was pretty goofy if you think about -- Yeeting a
| couple of dudes to the moon in a giant ass rocket so that
| they can tool around in a little electric-go cart with
| lawn chair seats and play some golf but it worked.
|
| I think that the Saturn V was a solid platform that was
| robust enough to do the kinds of things that Von Braun
| and others had in mind as well as versatile enough to be
| improved upon.
|
| They would have done it with sufficient budget but the
| political drive wasn't there. The politicians were more
| concerned with killing Vietnamese and Cambodians and then
| selling out American interests to oil companies.
| fsloth wrote:
| I guess the main problem was nobody had a budget for
| those plans. "Technically speaking we can do it but we
| can't afford it" unfortunately still means "we can't do
| it".
|
| Now only if Project Orion had not been canceled due to
| international treaties banning nuclear testing we'd be on
| the moons of Jupiter by now (sigh).
| neverrroot wrote:
| We just needed more people like Elon.
| ryandrake wrote:
| I don't get this hero worship. Elon Musk didn't build and
| launch this rocket. Thousands of engineers, scientists and
| technicians did. Elon wrote their salary checks, but anyone
| with gobs of money could do that.
| chgs wrote:
| They could. But they didn't.
|
| He's a twat. But he has vision longer than the next
| quarter and can inspire / coerce people into delivering.
| neverrroot wrote:
| Around the board, including at X.
|
| "Never been done before - xAI did in 19 days what
| everyone else needs one year to accomplish."
|
| He's a twat? What are your credentials?
| ceejayoz wrote:
| > "Never been done before - xAI did in 19 days what
| everyone else needs one year to accomplish."
|
| It's a lot less impressive being the _second_ person to
| fly a plane. Grok was released in November 4, 2023; Llama
| was released freely in February 2023. They had plenty to
| build off.
|
| > He's a twat? What are your credentials?
|
| What credentials would be relevant to determining that?
|
| I credit Musk for a lot of the vision behind SpaceX, but
| I'm glad he seems a bit distracted from it right now with
| X etc. It's possible to be both visionary and a twat
| simultaneously. Howard Hughes serves as a similar
| example.
| ryandrake wrote:
| > I credit Musk for a lot of the vision behind SpaceX
|
| For sure. Outstanding vision. I'll give him credit. But
| vision doesn't launch a rocket or finance a business.
| There are probably thousands of people out there with
| sufficient "vision" to build a space program, but only
| one of them is a billionaire willing to finance it. Musk
| is not some one of a kind unique person. He just happens
| to be one of the few who have the means ($$) to hire
| people who can actually bring his vision to life.
| pfdietz wrote:
| "There must be a beginning of any great matter, but the
| continuing unto the end until it is thoroughly finished
| yields the true glory." -- Sir Francis Drake
| vatueil wrote:
| People are prone to either giving Musk too much credit or
| too little.
|
| Musk isn't Tony Stark, single-handedly building
| everything. But then again, that's not how most
| innovations work.
|
| Engineers who worked directly with Musk, such as Tom
| Mueller, have spoken about Musk's technical acumen and
| involvement in managing projects.
|
| There have been many rocket programs, both public and
| private, that have accomplished less with more money.
| Bezos's Blue Origin, for example, started earlier than
| SpaceX and had a much richer backer for most of its
| existence, but is only now hoping to launch its first
| orbital rocket (and I hope they succeed).
|
| There's more to it than just writing a check.
| neverrroot wrote:
| He did so so much more than writing their checks. But
| what am I doing here, who am I seriously talking to?
| ridgeguy wrote:
| No. It all depends on cheap computation, reliable/free
| satellite location systems, and other stuff that weren't
| things in the (60s, 70s, 80s - pick your own starting point
| for "all along").
| bagels wrote:
| It's as much the economics as it is the technology. It took
| a ton of private investment, and government investment to
| get here.
| looofooo0 wrote:
| A rocket a day keeps the cost away.
| DaiPlusPlus wrote:
| Found the Factorio player.
| ChuckMcM wrote:
| That isn't exactly true though. For example, the neural net
| models that are used today in various GenAI startups were
| invented in the 1980s. But we couldn't have LLMs "all along"
| because we couldn't store the models, the training sets, or
| do the training compute with the computer hardware we had at
| the time. Similarly with rocketry there many technologies
| that have only been available in the last 10 - 15 years that
| make Starship possible. A sampling;
|
| First there are solid state inertial motion sensors[1]. Those
| combined gyros, accelerometers, and magnetometers that way
| just a few grams. Those bad boys weighed a couple hundred
| pounds in the Apollo rockets. We put the equivalent up in a
| $100 quadcopter these days.
|
| Second there is 3D printing of rocket engine alloy, this
| allows SpaceX to 3d print a raptor engine[2] both faster,
| lighter, and without error than any engine we could have
| built before 2010.
|
| Third was the development of fracking which created so much
| methane availability [3] that using it for rocket fuel became
| cost effective.
|
| Fourth and fifth changes were three decimal orders of
| magnitude on the ability of computers to compute with a
| commensurate drop in cost, and with that an explosion the the
| ability to use high frequency radio to do things that used to
| be done by cable harnesses and wiring. (sorry no citation,
| general knowledge)
|
| I can appreciate that it is really really hard to internalize
| how much as changed and improved since Apollo and can
| strongly recommend a trip to one's local science museum if
| you have one to get a visceral sort of amazement at what
| Apollo engineers did with the technology available to them at
| the time.
|
| So it isn't accurate to say we could have had this all along,
| although if one of the 'big' players like Lockheed Martin or
| Grumman Aerospace had continued investing even after the
| 'Star Wars' program was cancelled I do agree we would have
| had it sooner than we did. How much sooner? Maybe 5 years?
| But it is important to realize that at that time (late 80's
| early 90's) they didn't know that the Internet was going to
| be a thing and so they didn't have a built in "market" for
| all of that launch capability. Even with Teledesic[4] which
| tried to go there, you needed someone who like Musk who was
| too ignorant of what "could be done" to push a bunch of
| really smart people beyond what they thought they were
| capable of.
|
| [1] _Apollo PGNCS_ ---
| https://en.wikipedia.org/wiki/Apollo_PGNCS
|
| [2] _SpaceX simplifies Raptor engine: Has it used additive
| manufacturing?_ --- https://www.tctmagazine.com/additive-
| manufacturing-3d-printi...
|
| [3] _The U.S. fracking revolution has caused natural gas
| prices to drop 47 percent compared to what the price would
| have been prior to the fracking revolution in 2013._ ---
| https://www.brookings.edu/articles/the-economic-benefits-
| of-...
|
| [4] _Teledesic_ -- https://en.wikipedia.org/wiki/Teledesic
| philipwhiuk wrote:
| Not to mention solving the landing algorithm using work
| done for the Mars rovers.
| geepytee wrote:
| I just quit my job at a SaaS. What am I doing with my life... The
| SpaceX team just caught the biggest rocket in history with a
| giant arm, we all need to dream bigger!
| philipwhiuk wrote:
| https://x.com/mytechceoo/status/1845573520035577925
| efxhoy wrote:
| Strategically this is huge for the US and NATO. Being able to put
| orders of magnitude more payload in orbit at a fraction of the
| cost of the competition is a huge advantage in controlling space.
| Starlink and starshield are already years ahead of what china and
| russia has, starship is going to widen that gap even further.
| qaq wrote:
| Well if US would deploy global kinetic bombardment system that
| would def. be a game changer.
| polemic wrote:
| To get an _inert_ object through the atmostphere and do real
| damage it has to be very large. That 's a very inefficient
| way to use mass that you've boosted to orbit, even if it's
| relatively cheap to get there. So any weaponary they put up
| there will likely look fairly conventional. The speed of
| deployment and difficult of intercept would be the game-
| changer.
| vl wrote:
| But why not a kinetic weapon though? 1000kg tungsten rod
| coming at 5 km/s and 3000K will sink any ship.
|
| A bit tricky to aim though - basically the moment you
| initiate the burn for re-entry, you give 15 minute warning.
| kaliqt wrote:
| Well you answered it yourself, anyone competent can dodge
| that. It's useful for attacking existing installations,
| but well, you can do that with any weapon.
|
| Plus it's easier to intercept orbital bombardment since
| you know where it is ahead of time and have plenty of
| time to intercept.
| qaq wrote:
| it takes few minutes for it to reach target so no it's
| not easy to intercept also what exactly are you planing
| to use to intercept a solid tungsten rod with exactly?
| vl wrote:
| But it's true for any orbital-based weapon that needs to
| de-orbit for striking. Once it starts retro burn you know
| it's going for strike and know where it's going to
| strike.
| grecy wrote:
| Aim it at something that can't move
| TMWNN wrote:
| My understanding is that rods from god are not easily
| detectable during reentry the way an ICBM's warhead is.
| pfdietz wrote:
| I don't see why that would be.
| snek_case wrote:
| You could also just put a ballistic missile on a
| satellite, then you'd have a guidance system.
| bloopernova wrote:
| Or a GPS guided bomb. Just fire it from a small rocket
| and let gravity do its thing.
| vl wrote:
| It needs to re-enter, i.e. have the thermal shield, etc.
| This is what this Starship thing is all about - re-entry
| is really hard. Regular guide bomb is just going to burn
| or re-entry into atmosphere.
| vl wrote:
| Any warhead needs guidance system. The question is if
| passive kinetic payload is enough or it should be
| something with explosives.
| bloopernova wrote:
| I've wondered about that. In a series of sci-fi books
| (the lost fleet series, starting with _Dauntless_ ), our
| intrepid heroes bombard military bases with BFRs. Big
| fucking rocks. Which are tungsten slugs coated with
| ceramic I think.
|
| These are fired from light hours away at approximately
| 0.2 to 0.3 c. I had assumed that something going so fast
| would just disintegrate if it hit an atmosphere head on?
| The projectiles are described as "increasing velocity" as
| they approach, and they strike with gigaton effects. I
| remember reading an xkcd that showed something traveling
| so fast in atmosphere would cause huge explosions from
| air turned into plasma.
| vl wrote:
| Depends on the mass of the object, of course, but at at
| this speed (i.e. energy) it will become a stream of
| particles going through atmosphere and vaporizing
| anything in it's way.
| TrapLord_Rhodo wrote:
| a 20 foot long Tungston rod hitting at 10km/s would release
| 416 gigajoules of energy. Pretty much a small nuclear bomb
| or about 100 tons of TNT.
|
| It's impossible to intersept something going 10km/s.
| restalis wrote:
| The most expensive part is to support the risk and cost of
| research & development. Sure, that renders you the first place
| for a while, but expect others to move easier (and thus faster)
| after you marked the trail.
| joejohnson wrote:
| Amen! If it turns out we can't make humans a multiplanetary
| species in any reasonable timeframe, at least we can make the
| last few decades of livable earth climate a friendly atmosphere
| for US business interests.
| sharlos201068 wrote:
| Even the worst expected impacts of climate change will leave
| earth tremendously more habitable than anywhere else in the
| solar system.
| pfdietz wrote:
| Even a nuclear war would have that outcome. Even a KT
| boundary scale asteroid impact would have that outcome. The
| rest of the solar system is just hell.
| whimsicalism wrote:
| There are plenty of imaginable events where being
| multiplanetary would help.
| pfdietz wrote:
| Like what? Gray goo?
| WalterBright wrote:
| As an ME/AE, I can say this is an astounding engineering
| achievement. And on the _first_ try! Well done, SpaceX!
| ipsocannibal wrote:
| The V2 was also revolutionary and also developed by fascists.
| https://www.theatlantic.com/politics/archive/2024/10/donald-...
| iwaztomack wrote:
| What parts of this can be reused? I bet the engine is OK, but
| seems like the sides of the ... tube ... were pretty roughed up.
| I guess that's probably the cheapest part of the assembly though.
| valine wrote:
| All of it can be reused. Their plan is for the tower to set the
| booster back down and immediately relaunch it.
| nine_k wrote:
| Everything except the stage connector ring (which uses pyro
| bolts I believe) should be directly reusable, after an
| inspection, light brushing, and refueling / recharging.
|
| Maybe the bottom uses some ablative material, then a new coat
| of it needs to be applied / attached.
|
| All the internals should have enough resource for likely dozens
| of launches, if Falcon-9 is any indication.
| slimebot80 wrote:
| The SpaceX engineers did a great job, as did NASA.
|
| The media needs to stop blindly attributing this to "Elon Musk".
| He did well taking the risks NASA was not allowed to take at the
| start. But these days he is toxic to the media and toxic to
| reporting, so for that reason alone the media could smarted up a
| little. Well done SpaceX and NASA engineers.
| bottlepalm wrote:
| Elon is the guy who said, "that is the craziest idea I've ever
| heard, here's billions, let's build it"
|
| It's 100% Musk that this happened, literally no one else would
| have done it. Everyone thought it was dumb until today. No
| company, no government or sci fi movie for that matter had even
| thought of it in the first place.
|
| SpaceX engineers given the green light by Musk, not NASA, made
| it a reality. That's not to say Elon didn't make many decisions
| along the way in the design and development of both Starship,
| the launch towers and everything else.
|
| The point is, Elon deserves a hell of a lot of credit along
| with everyone else. Everyone has their part to play in the
| success of the mission.
| TMWNN wrote:
| >The media needs to stop blindly attributing this to "Elon
| Musk".
|
| Musk's biographer tweeted the pages from his book
| <https://x.com/WalterIsaacson/status/1844870018351169942>
| discussing how in late 2020 Musk suggested, then insisted
| against considerable opposition from his engineers, that
| Superheavy be caught with chopsticks instead of landing on legs
| like Falcon 9.
|
| (If this sounds familiar, also according to the book, Musk is
| the person who suggested and, against considerable opposition
| from his engineers, insisted on Starship switching to stainless
| steel instead of carbon fiber.
|
| Hint: Musk was right and his engineers were wrong. Both times.)
| poszlem wrote:
| Musk is the one who makes this possible. There's a reason why
| neither Bezos, Gates, nor Branson are anywhere close to this
| achievement, despite also having vast financial resources. I
| strongly dislike this attempt to erase Musk from the history of
| what's happening (mostly because people disagreeing with him
| politically). It is an absolute achievement of all the
| scientists and engineers at SpaceX. It is also a huge victory
| and validation for Musk and his way of leading. Both of these
| statements can be true simultaneously.
| ein0p wrote:
| Would this get the "Elon musk is not very bright because I don't
| like his politics" crowd to finally STFU? Rhetorical question, of
| course not.
| animal_spirits wrote:
| What does this mean for the Kessler syndrome? Does reusable
| rockets speed up our potential for lock-in or slow it down?
| 93po wrote:
| I am absolutely flabbergasted at this. Wow. Jesus christ.
| atleastoptimal wrote:
| Why can only Elon do stuff like this and not BlueOrigin or the
| hundreds of other aerospace startups? Does he just have a
| 1/100000000 combination of intelligence, tenacity, and
| directionality that can't be matched by anyone, even those trying
| to emulate him as closely as possible?
| neom wrote:
| Isn't BlueOrigin going after at totally different market
| segment, I thought it was focused on things like space tourism
| and more "space base" type stuff? Also pretty sure BlueOrigin
| is almost all funded by Jeff B, SpaceX has a lot of external
| funding and focused on tangible markets vs just "people will
| want to do stuff in space" - I think it was only very recently
| they started to work with NASA.
| skissane wrote:
| > Isn't BlueOrigin going after at totally different market
| segment, I thought it was focused on things like space
| tourism
|
| They have New Shepard, a crew-rated suborbital spacecraft,
| primarily targeted at tourism, but it has also done some
| science payloads for NASA, university and commercial clients.
|
| But they also are doing a lot of non-tourism stuff: they
| designed and manufacture first stage engines for ULA's new
| Vulcan launch vehicle; they have their own reusable orbital
| launch vehicle (New Glenn) due to launch soon (planned for
| next month, but might slip to early next year); they have a
| contract with NASA to build a lunar lander to compete with
| SpaceX's; they are part of one of the teams NASA has chosen
| to compete for the contract to build a commercial ISS
| replacement.
|
| And SpaceX is involved in space tourism too: both directly,
| and indirectly via resellers such as Axiom.
|
| It is just that the most publicly noticeable thing Blue
| Origin has achieved is space tourism, which makes people
| think it is primarily a space tourism company; meanwhile,
| SpaceX has had numerous publicly visible achievements other
| than tourism, so people view tourism as just another thing
| they do, not their main thing.
| thisisthenewme wrote:
| Why do we think its Elon 'doing' this? Just curious, since it
| could just as well be that its the engineers and other leaders
| who could be the differentiator.
| atleastoptimal wrote:
| I would agree with that if it weren't the case that the
| collection of engineers and other leaders working under Elon
| consistently outperform their competition in multiple
| domains.
| bottlepalm wrote:
| Because it's Elon who said "ok, build it." There's no one
| else except him with that power and/or the guts. Even landing
| a rocket the government had given up on, and no company was
| even trying until he did. People were calling the 'chopstick'
| landing system a dumb idea until today.
|
| It's not like engineers don't come up with wild ideas all the
| time to their leadership, but is the leadership good enough
| to understand the good ideas from bad ones? Take the risk,
| spend billions to actually execute?
|
| Elon has enough of a physics/engineering background to ask
| the right questions, understand the trades engineers put in
| front of him, and make the risk/reward calculation to make
| the right decisions the ends up winning.
|
| To get what SpaceX has you need strong technical leadership
| all the way up the chain. Many companies don't. Their CEOs
| are experts in legal, PR, finance, etc... They make poor
| technical decisions.
| kaliqt wrote:
| Because he is the kingpin. He chooses the staff, he guides
| them, he does everything at a high level.
|
| You can hire new executives, you can't easily find a new
| Musk, and then you will fail.
|
| See the problem?
| dools wrote:
| Code name: Danielsan.
| TechSquidTV wrote:
| I grew up playing Halo, and this was purely fiction at that
| point.
| iamgopal wrote:
| I don't understand, the starship has to stand on something, and
| what ever that is in contact with ( arm or barge or land or
| whatever ) , needs to be as heavy, how they are saving weight ?
| seany62 wrote:
| Unbelievable. Amazing.
| modeless wrote:
| Update: SpaceX has set the booster back down on the launch mount
| and reconnected the "quick disconnect" hoses that fill it with
| propellant before launch. If they refilled it with propellant
| they'd be close to launching it again! Presumably they will be
| draining it instead.
|
| Apparently the rails that catch the booster can translate in and
| out relative to the "chopstick" arms so the booster can be
| positioned and rotated to match the launch mount after landing.
| pfdietz wrote:
| I wonder if they recover the helium used to pressurize the
| propellant tanks.
| cryptonector wrote:
| This is a very important update. Where would we find out more
| about this? Was this in a YouTube video somewhere?
| ziofill wrote:
| What is the advantage of catching the booster vs letting it touch
| down?
| itishappy wrote:
| You don't have to send most of the landing hardware into space.
| ziofill wrote:
| That makes sense, thank you!
| fnord77 wrote:
| I still think the Space Shuttle was more impressive.
| smoovb wrote:
| Now go back 7 years and watch the proposal for 1 hour flight
| anywhere in the world -
| https://youtu.be/2tf2KpCG2fM?si=EfDUcL4x7MpGt51C&t=27
| wojciii wrote:
| This chopstick catch was really impressive. I had my money on
| them managing it the first time. I haven't been so excited since
| the dual landing of their Falcon 9 boosters.
| gzer0 wrote:
| An incredible achievement. I'm honored to be part of this moment
| in history.
| belter wrote:
| Another great view: https://youtu.be/Vzyaud250Xo
| iamsanteri wrote:
| After watching this the project of changing brakes on my old car
| doesn't feel like that big of a project anymore.
| sgu999 wrote:
| Does anyone know of a live map where we can see the trajectory of
| launches? Wondering if starship went above my head during
| reentry, but I can't find the info
| ugh123 wrote:
| Do we know if there was a test payload?
| jvesalius wrote:
| Yes, there was none.
| throwaway2037 wrote:
| Sorry for the newbie rocket question: Blast off happens around
| 33:00 in that video. The rocket appears to be vertically still
| (does not move) for the first 4 to 4.5 seconds. Is it held in
| place, or are not enough engines burning (yet) to induce take-
| off?
| patall wrote:
| While I cannot say if it moves immediately, it definitely moves
| within 2 seconds. It does not appear to move because it is so
| massive at more than 100 meters.
| 0x1ceb00da wrote:
| If twitter is x, does that mean spacex is space twitter? Twitter
| was rebranded after elon bought it.
| isolli wrote:
| Question I can't find the answer to anywhere: considering that
| SpaceX already had other ways of re-using boosters, why are they
| doing this?
|
| Is it to explore more options? Or because it's faster to re-use
| the booster if it's already in place? Were the other approaches
| not satisfactory, perhaps? Or no longer applicable due to size?
| melodyogonna wrote:
| First because the rocket is lighter without landing legs.
| Second because they're aiming for rapid reusability, they want
| to tower to catch the rocket, lower it to the launch mount, and
| get another Starship stacked on it.
| fragmede wrote:
| mass that's on the tower that was moved to the rocket is no
| longer on the rocket, which means the rocket can carry more
| fuel/payload. hence the tower catching the rocket instead of
| the rocket having heavy landing gear.
| cahaya wrote:
| Great launch! Would be nice if the starship itself would be
| landing on the chopsticks next time and land during day time
| instead of dark Australia.
| mentos wrote:
| Crazy that the chop stick catch was originally eye rolled by the
| engineers and then when he pushed for it they realized he was
| serious.
| bowsamic wrote:
| Very difficult to enjoy with all the screaming
| isthatafact wrote:
| For some reason, the spacex screams sound nightmarishly
| terrifying to me.
| UltraSane wrote:
| The contrast between SpaceX's success at creating reusable
| rockets and Tesla's failure at FSD is pretty stark.
| philipwhiuk wrote:
| To be honest FSD is way harder. The platform doesn't
| occasionally have a road closure sign or a new traffic light or
| a guy unloading his van or an emergency vehicle with its
| hazards on.
|
| Don't get me wrong the engineering and physics are crazy ugly,
| but it's at least consistent within a range. Humans are messy,
| unpredictable, unreliable and chaotic.
| abustamam wrote:
| This is truly an amazing feat! Congratulations to the SpaceX
| team.
|
| Can someone explain to me exactly WHY it's such a big deal
| though? Like subjectively I can see it's incredible but while
| watching the video there were enormous applauses at points I knew
| were a big deal but I lacked the understanding of physics to
| truly appreciate.
| chadhutchins10 wrote:
| For humans to have any reasonable presence somewhere else in
| our solar system (moon, mars, etc.) we need the ability to
| launch tons (literally tons) of stuff to orbit and to the
| destination. and we need to launch it often to do anything in a
| reasonable amount of time. the only way to do that is to make
| reusable launch systems. SpaceX's Falcon 9 has aced that for
| satellites (see Starlink and everything else they've launched).
| The Starship launch system is capable of launching a
| significantly larger payload, ~20 times more. What they
| demonstrated yesterday is that a launch system that is capable
| of getting us anywhere in the solar system can be reusable.
| Huge accomplishment.
| Fin_Code wrote:
| The current Falcon rocket always expends a stage and lands a
| stage. Starship will land both stages. Also Starship is far
| larger and in rocketry there is something called the square
| cube law that means bigger is better. So its far more
| efficient. That leads to far cheaper mass to orbit costs.
| cryptonector wrote:
| In order to land not just the first stage but also the second
| stage more fuel will have to be carried on the ascent phase
| just to enable the recovery phase. This then necessitates
| weight savings elsewhere to avoid payload to orbit being cut
| way back. SpaceX chose to remove the landing system from
| both, the first and second stages (both because, after all if
| you can eliminate the landing system from one stage then you
| can eliminate it from the other).
|
| This and other weight savings will enable high payload to
| orbit in a fully reusable launch platform.
|
| Landing without legs requires something like this catch
| system -- something never done before, and clearly very
| difficult to do.
| nottorp wrote:
| Just to nitpick, perhaps it would be nicer to have a link that
| has the info visible without a login...
|
| Random link with the actual 10 minutes of magic:
|
| https://www.youtube.com/watch?v=b28zbsnk-48
| carabiner wrote:
| We have done much, but there is much to be done.
| exabrial wrote:
| I think that catching a grain silo in mid air that fell in a
| semi-controlled way from effin low earth orbit is undeniably
| incredible.
|
| SpaceX continues to blow me away with these unbelievably lofty
| ideas. I remember seeing their "grasshopper" flights years ago
| and they blew it up because they couldn't land it at the time,
| who knew within a few years they'd be doing this.
| chippiewill wrote:
| I think they still have "Grasshopper" (the custom test unit)
| sat outside at McGregor, it was F9R Dev1 (a modified F9
| booster) that they had to destruct after one of the engines
| failed mid-hop.
|
| They were originally going to do high-altitude tests with an
| "F9 dev2" (similar to some of the early starship test launches)
| - but they gave up and just did some testing with real landing
| Falcon 9s instead.
| Hacktrick wrote:
| yea this seemed like simple PID control to me, nothing impressive
| _yawn_
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