[HN Gopher] SpaceX launches Starlink sats in record 10th liftoff...
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SpaceX launches Starlink sats in record 10th liftoff, landing of
reused rocket
Author : _Microft
Score : 75 points
Date : 2021-05-09 18:39 UTC (4 hours ago)
(HTM) web link (www.space.com)
(TXT) w3m dump (www.space.com)
| aurizon wrote:
| It is quite apparent that the NASA/Government space industry has
| milked the public for 50+ years. We could have had re-useable
| first and higher stages decades ago. Then along came Spacex and
| revealed this scandal.
| internetslave wrote:
| Yup. Now apply the same thinking to the rest of government
| shadowgovt wrote:
| I don't think I'd frame it that way.
|
| SpaceX is taking advantage of technologies that weren't
| available until recently. Of course, now that they are
| available, we should see SpaceX's competition adopting them.
| pfdietz wrote:
| Something very much like an expendable F9 could have been
| made decades ago. Simply evolving the Saturn 1B might have
| done it. But no, Nixon needed pork in California to ensure
| his reelection.
| ceejayoz wrote:
| > Something very much like an expendable F9 could have been
| made decades ago.
|
| We've made non-reusable rockets for quite some time pre-F9.
| bodhiandphysics wrote:
| Not really. Falcon 9 is more sophisticated than it looks at
| first glance. Merlin has extremely high performance when
| compared to earlier gas generators... it has a t/w of 200
| compared to the ra-27s 100 or the f-1s 95. The alluminum
| lithium alloys that give the rocket such a low dry mass
| date from the 90s. The avionics in falcon are
| revolutionary, and couldn't have been possible before the
| early 2000s... a lot of little things like that.
| pfdietz wrote:
| That's why I said "evolving". Making engines better,
| introducing FSW when it was introduced, and so on. The
| F9-like boosters that could have been made around 1972
| would still have been much better than the shuttle turned
| out to be.
|
| What one should object to in this scenario is the idea
| that the conventional aerospace companies, and NASA,
| would have done anything like this, when their internal
| incentive structures pushed them away from it.
| bodhiandphysics wrote:
| We did build an f-9 like booster around the time of the
| shuttle, the delta ii. It doesn't compare to falcon.
| Neither does Antares, built at the same time as the f-9
| pfdietz wrote:
| Delta-II was not a F9-class launcher. The first stage
| thrust (ignoring strapons, which one should because F9
| doesn't use them) was less than 1/7th that of the F9. A
| closer match was the Saturn IB.
| bodhiandphysics wrote:
| Delta ii was designed around boosters! Also when falcon 9
| was developed its target payload was ten tons to Leo,
| similar to delta ii's 8
| low_common wrote:
| Wait, what?
| credit_guy wrote:
| I think what the GP is trying to say is that reusable rockets
| had been known and built by NASA 50 years ago. More
| precisely, the Moon lander was just such a rocket that was
| able to land and then to lift off, albeit on the Moon, not on
| Earth. But the concept was there, it was just a matter of
| scaling it up.
|
| By the way, I don't personally buy this argument, but it's
| not completely meaningless either.
| ceejayoz wrote:
| The moon lander wasn't really reusable, though. It was a
| two stage disposable rocket that happened to hang out
| somewhere during the interstage period. Calling it
| "reusable" is like calling the Apollo capsules reusable
| because they go up, then down.
|
| SpaceX benefits enormously from fast computers, advances in
| metallurgy, CAD, etc.
| hwillis wrote:
| They may also be referring to the McDonnell Douglas DC-X.
| It flew and landed itself in 1996, but it was heavily based
| on the 1967 Douglas SASSTO.
|
| Neither project was government funded or ordered. There's
| no particular reason to think it could have even been built
| in 1967, and even in 1996 it may not have been possible to
| land a rocket after reentry. Coming in backwards at
| supersonic speed is incredibly challenging. Flipping around
| would have been even more so. Transitioning from supersonic
| to subsonic would have been a total guess. The DC-X
| certainly could not have done any of those things.
|
| The OP may also not understand the incredible gulf in
| difficulty between landing a suborbital rocket and a real
| first stage. A suborbital rocket doesn't weigh that much
| more going up than it does going down. The F9 first stage
| weighs less than 5% of what it has to lift on the way up.
| Getting a rocket to output 25% thrust is easy; use four
| engines and turn off 3. You can't just turn off 19 engines;
| the F9 first stage is huge and needs huge power swings to
| remain stable.
|
| SpaceX built custom sparse voxel GPU solvers to design
| around combustion instabilities and supersonic flows around
| the rocket. Even in the 90s they would have had to make
| huge concessions for the sake of running 20+ engines at
| once. There's absolutely zero chance they could have done
| it in the 60s or 70s.
| davidaa wrote:
| Let's not oversimplify or cast blame. Sure, most/all of the
| tech has been around for decades - although Lars Blackmore &
| the other controls engineers did original work that was
| arguably absolutely critical - but there hasn't been any
| milking going on. The most profitable route wouldv'e been to
| develop this tech & then use it, after all. [Case in point:
| SpaceX, of course.] There simply wasn't enough interest from
| the public or Congress to put enough R&D money into any number
| of cool programs to see them through to commercialization.
| wolf550e wrote:
| Boeing and Lockheed Martin, separately and together under the
| name of ULA, and Northrop Grumman (as Morton Thiokol, ATK,
| Orbital ATK and now NGIS) have been milking the taxpayer for
| decades. Their business plan always involved making
| everything take longer and be more expensive. That is what
| they have to do to make more money, because they work on
| "cost plus" contracts.
|
| An engineer in any one of them who presented a way to make
| the rocket cheaper to his boss would have been fired for not
| understanding how the company makes money.
|
| The oversight is supposed to be done by congress, but they
| are extremely happy to provide good paying jobs in their
| districts, for decades.
|
| No one even really hides it anymore. Any official, when asked
| about something like SLS and costs, would answer with "But
| NASA is going to the moon! Don't you want America to go to
| the moon?!" and with "tens of thousands of high paying jobs
| in all 50 states". There is no attempt to say the rising year
| over year price of orbital launch (before SpaceX), the
| exorbitant price of SLS + Orion, the use of solid boosters
| for crewed launches, etc, make any sense except to support
| the existing contractors to the detriment of the tax payer
| and space exploration.
|
| See a NASA insider explaining:
| https://www.youtube.com/watch?v=g3gzwMJWa5w&t=463s
|
| (Or see anything by Dr. Robert Zubrin, or see the story of
| how the shuttle derived design that lost to RAC-2 (a Saturn V
| like design) was chosen to be "SLS":
| https://www.youtube.com/watch?v=ZNZx208bw0g&t=1970s)
| 0x000000E2 wrote:
| NASA nah, they transitioned to third party launch providers
| many years ago. They like making space vehicles more than
| rockets. The SLS, yes, that's a classic pork project.
|
| ULA is the real problem. The government allowed all the launch
| providers to merge into one with no domestic competition. Think
| space Comcast. Other countries allowed the same. Nobody
| innovated for decades. Russia and US ULA are flying rockets
| from 50 years ago with minimal updates.
| tehbeard wrote:
| > Russia and US ULA are flying rockets from 50 years ago with
| minimal updates.
|
| Old Babushka proverb, if complicated explosion related
| plumbing is working as intended, best not to completely
| rework it for sake of changelog.
|
| Minimal updates to the shape, maybe?
|
| But I bet the electronics and manufacturing have seen steady
| improvements over that time.
|
| SLS does feel quite like a pork barrel, but I understand the
| funding of it along with the other commercial companies as
| "more options, less risk", if something grounds the Dragon
| capsules, having a "home" alternative instead of buying seats
| on a foreign rocket makes sense.
| 0x000000E2 wrote:
| > Old Babushka proverb, if complicated explosion related
| plumbing is working as intended, best not to completely
| rework it for sake of changelog.
|
| Aye, but everyone stuck with that proverb for too long.
| Then Musk appeared and he doesn't seem to care that his
| test rockets explode. He revels in it.
|
| To me it's the classic startup vs giant corporation. The
| bigger you are, the harder it is to change course. And
| exploding rockets look bad to management. The same reason
| so many companies are still on IBM mainframes running
| FORTRAN.
|
| SLS is an insurance policy against SpaceX. But it's being
| managed by the same old wasteful monopolies as always, plus
| plenty of government mandated pork.
| vardump wrote:
| Your nickname, 0x000000E2... ERROR_VIRUS_DELETED?
| 0x000000E2 wrote:
| My favorite Windows error :)
|
| I wanted [object Object] but it was taken haha
| simonh wrote:
| The essential features of the F9 that made it capable of
| propulsive landing were an accident. After the success of the
| F1 SpaceX didn't have the resources to develop a larger engine,
| so they built the bigger rocket by just adding a cluster of
| engines to the first stage. This is far from ideal because
| multiple small engines gives poorer power to weight than fewer
| big engines, but SpaceX hoped to gain cost advantages by mass
| producing the engines.
|
| The original plan for recovering the F9 first stage was to use
| parachutes and this was tried with the first couple of
| launches, but the boosters broke up on re-entry. That's when
| the idea of a re-entry burn came up, and from that the concept
| of a propulsive landing.
|
| But propulsive landing is only possible with the F9 because it
| has a central engine and the engines are small enough to
| throttle down low enough to do a suicide burn. You have to have
| an engine at or very close to the centre of the vehicle for it
| to work. But this 9 engine cluster with a central engine was
| not originally designed with propulsive landing in mind. It was
| an accident.
|
| If SpaceX had better funding early on, they probably would have
| developed a larger main engine for the booster, which wouldn't
| have been able to throttle low enough to stick a landing and
| may not have had a cluster arrangement with a central engine
| anyway. This is also why the other rocket companies mostly
| can't adapt their rockets for reusability easily.
| imron wrote:
| It's amazing how much scientific progress is caused by
| accident.
| Denvercoder9 wrote:
| _> This is far from ideal because multiple small engines
| gives poorer power to weight than fewer big engines_
|
| Are you sure about that? The Merlin engine Falcon 9 uses has
| the highest thrust-to-weight ratio of any rocket engine
| currently being used, more than double that of the much more
| powerful RD-180 used on the Atlas V. You'll lose some
| advantage because structural support and plumbing for more
| engines is heavier, but I'd expect they'll still come out
| ahead. The Raptor has been downsized from the original plans,
| and Musk has said that was to improve thrust-to-weight ratio.
| simonh wrote:
| It's a fair point but how many engines have been through
| such an aggressive optimisation and upgrade program?
| Arguably a bigger brother of Merlin going through the same
| process should be more efficient.
| Denvercoder9 wrote:
| _> Arguably a bigger brother of Merlin going through the
| same process should be more efficient_
|
| Why? I can't think of any reason why more powerful
| engines would fundamentally be more weight-efficient.
| justapassenger wrote:
| We could've landed on the moon in 18th century as well, right?
| Given that we landed in 20th century, it's just a conspiracy
| that we didn't do it earlier.
| smaddox wrote:
| Doubtful. Landing on the moon prior to the commercialization
| of BJT's would have been staggeringly more difficult.
| [deleted]
| mabbo wrote:
| My wife was watching a show about plane spotters, and them
| watching the last 747 flight from the UK. I was making some
| flippant comment, like, come on this is such a weird hobby.
|
| She then pointed out that I know the ID of every active SpaceX
| booster, including prototypes, and watch nearly every launch
| live.
|
| Oh no. I'm a rocket spotter.
| m463 wrote:
| The saying I remember is... "When you point a finger at
| someone, your other fingers are pointing back at you" :)
| HPsquared wrote:
| I suppose there was a time when planes were as rare and special
| as rockets are today.
| garciasn wrote:
| I watched the train go overhead with my wife, son and neighbor on
| Friday night. While I've seen them before, it was exciting to
| share my 11 year old son's awe.
|
| I know there's concern about these LEO sats, but we still enjoyed
| counting the train as it streamed almost directly overhead from
| West to East.
| _Microft wrote:
| As much as I understand astronomers' apprehension of satellite
| internet constellations but the first Starlink 'train' we saw
| from the top of a hill was absolutely captivating. I cannot
| begin to describe the beauty of a line of sparkling dots,
| moving unerringly but silently over the sky.
| AprilArcus wrote:
| More beautiful than the stars and galaxies they're blotting
| out?
|
| I hear this and it's like someone admiring the engineering of
| a cloverleaf exchange running over a buried river.
| TeMPOraL wrote:
| > _More beautiful than the stars and galaxies they 're
| blotting out?_
|
| Very much yes!
|
| Stars and galaxies _are_. They are as they always[0] were,
| and always will be. Blobs of fusing hydrogen very far away.
| As beautiful as they may be if we could see them better,
| from where we are, they 're just points of light.
|
| (Also, wait a few seconds, the satellites will pass, and
| you're back to watching the stars behind.)
|
| A constellation of satellites in the sky is also just a
| bunch of points of light. But it's more than that. It
| _means_ something. Humans have put it there. Those
| satellites serve a purpose, and their appearance on the
| night sky reminds us of the great discoveries and feats of
| engineering that were necessary to put them there. They 're
| a testament to the ingenuity and potential of mankind, and
| the promise that one day, our descendants will travel among
| them.
|
| That's what I see when I see a satellite passing overhead.
|
| > _it 's like someone admiring the engineering of a
| cloverleaf exchange running over a buried river_
|
| Sure, it's exactly that. A cloverleaf exchange is
| _interesting_. It 's not something that _just happens_ ,
| and its shape is not random. A river is boring. Also full
| of insects that try to feast on your blood.
|
| I'm totally serious, by the way. Ever since a kid, I've
| found nature boring. This actually changed for me in my
| adulthood - my interest in biology sparked when I realized
| that life is just molecular nanotechnology that wasn't
| designed by humans, but could still be eventually
| understood and controlled.
|
| --
|
| [0] - On human-relevant timescales.
| bryanlarsen wrote:
| The trains are only visible within a half hour of sunrise &
| sunset, when those stars and galaxies aren't particularly
| visible due to incident sunlight. If you want to see the
| stars and galaxies, look up at midnight when Starlink isn't
| illuminated by the sun. It was the best view before & after
| Starlink.
| trompetenaccoun wrote:
| Is there any realistic estimate for how much cheaper SpaceX will
| be, compared to bringing cargo up on traditional rockets? I've
| seen Musk claim something ridiculous like it's 1% of the cost of
| legacy systems but guess that should be taken with a grain of
| salt.
| solarkraft wrote:
| Thunderf00t, in one of his critical videos, puts break-even at
| 3 launches, IIRC.
| bodhiandphysics wrote:
| Let's compare how much cheaper spacex is. For a 5 ton geo bird,
| spacex is about 2/3 the price of its competition. This however
| is price not cost. The best estimate for starlink is that
| SpaceX's cost per satellite is about 500 thousand. This
| compares to oneweb's 2 million per sat, for says that weigh
| half as much. Starship could have a cost (not a price) that is
| very low indeed.
| Veedrac wrote:
| Falcon 9 is about half the price of competitors right now,
| though the internal cost is under half that again; a lack of
| competition has prevented SpaceX from needing to lower prices
| further.
|
| Starship doesn't have an unambiguous cost because it's
| dependent so heavily on factors like market size, whether the
| Mars thing happens, and reliability. A marginal cost of a few
| million dollars is an explicit goal, but a more short-term
| rough goal is about Falcon 9 prices, or $50m/launch. That's
| both a very reasonable number, and also still more than 10x
| better than the competition.
|
| https://youtu.be/GomoD0rYhJ8?t=1285
| _Microft wrote:
| So, does anyone wanna guess how many reuses SpaceX will get out
| of a booster?
| LeoPanthera wrote:
| They replace broken and worn parts, so at some point this
| becomes the Booster of Theseus problem. How many parts can you
| replace before it is not the same booster anymore.
| foobarbecue wrote:
| I'm pretty sure it's when you replace the big metal tube
| part.
| perlgeek wrote:
| I don't think anybody really knows; there simply isn't any data
| with > 10.
|
| Back in the days when boosters were recovered, I remember
| hearing somewhere that SpaceX was confident that they would be
| able to fly them 10x, and hoped for 100x
| grecy wrote:
| Elon said they'll keep reusing them and pushing their luck
| until they have a failure on a starlink launch... so we're
| almost certainly going to find out.
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