[HN Gopher] A rocket a day keeps the high costs away (1993)
___________________________________________________________________
A rocket a day keeps the high costs away (1993)
Author : joebig
Score : 87 points
Date : 2024-01-05 18:38 UTC (4 hours ago)
(HTM) web link (www.fourmilab.ch)
(TXT) w3m dump (www.fourmilab.ch)
| mrkstu wrote:
| Remarkably prescient. Any public knowledge whether Musk has cited
| this as an inspiration? This arstechnica article feels like a
| direct descendent: https://arstechnica.com/space/2024/01/elon-
| musk-spacex-needs...
| philipwhiuk wrote:
| It's not really that novel.
| SCM-Enthusiast wrote:
| the novelty is how to handle such scale.
|
| Sure, if we build a million rockets it'll be cheaper, but how
| do we USE those rockets and get funding at "relative peace
| time". SpaceX's real innovation was starlink in allowing it
| to "Soak up" excess production. Besides the obvious of
| reusability, which wasn't that "Obvious" considering the
| temperatures of reentry.
| JumpCrisscross wrote:
| > _SpaceX 's real innovation was starlink in allowing it to
| "Soak up" excess production_
|
| SpaceX had a lot of real innovations. Starlink is one of
| them, but it's not in the top five.
| gertlex wrote:
| Might be referring to top "business plan innovations".
| JumpCrisscross wrote:
| > _Might be referring to top "business plan innovations"_
|
| No. 1 and No. 2 are positing a private space company and
| mass manufacturing. Those are, hands down, SpaceX's
| transformational business plan innovations.
|
| COTS, No. 3, is a business-engineering hybrid. Using NASA
| funds as stepping stones, versus treating them as the
| ends, No. 4. Maybe we can slot Starlink into No. 5, but
| it wasn't unpredictable; telecom was always the
| moneymaker in space. (I'd argue published pricing with
| online ordering nudges it out.)
| IshKebab wrote:
| Starlink isn't even a new idea.
| https://en.wikipedia.org/wiki/Teledesic
|
| As always, ideas are cheap. SpaceX is doing well because
| it's actually managing to successfully implement lots of
| old fantastical ideas.
| btilly wrote:
| Actually, reusability was an obvious idea from the start.
| For example the Space Shuttle and the McDonnell Douglas
| DC-X are examples of attempts at reusability in the USA,
| and other countries had their own experiments.
|
| It just became non-obvious that it was the right approach
| after a long history of failed attempts at it.
| panick21_ wrote:
| The Shuttle was the only serious attempt. And even then,
| they dropped the largest structural part and used solids
| that can't practically be reused anyway. The DC-X is just
| a research project, that they would ever develop a
| reusable launch was basically fantasy.
|
| The same in other countries, very little actual large
| investments.
|
| The Soviet Shuttle was even less reusable then the US
| one. And that was actually pretty smart of them.
|
| So I don't think that were that many real failed
| attempts. There was practically speaking one real
| attempt.
| SCM-Enthusiast wrote:
| it was always the "Right approach" and everyone knew that
| there was nothing in the laws of physics that prohibits
| this. But you are writing that as if it's still be
| solved.
|
| No one has ever had a fully reusable orbital rocket..
| still to this day. Althought starships got a shot.
| mlsu wrote:
| Starlink wasn't really considered for years until SpaceX
| already was well underway.
|
| It was fortuitous but unplanned, not a factor in the
| original vision of the company when it was founded.
| twic wrote:
| Before Starlink, SpaceX assumed/hoped that a mass of new
| customers would come out of the woodwork when cheap
| launches became available (the easyJet strategy!). When
| they didn't, they came up with Starlink to be that
| customer.
| foobarian wrote:
| Although, aren't they launching something pretty much
| daily or weekly, even without accounting for Starlink? It
| just isn't in the news much.
| twic wrote:
| I picked September last year [1] more or less at random;
| SpaceX launches by day of the month: 01 -
| Starlink 02 - military 04 - Starlink 09
| - Starlink 12 - Starlink 16 - Starlink
| 20 - Starlink 24 - Starlink 25 - Starlink
| 30 - Starlink
|
| A skim through the other months suggests that per month,
| there is usually one US government launch, zero to two
| commercial or rideshare launches, and a bunch of Starlink
| launches. There is an amazing range of stuff on the
| rideshares!
|
| [1] https://en.wikipedia.org/wiki/List_of_spaceflight_lau
| nches_i...
| panick21_ wrote:
| There are lots of new costumers. The thing is just that
| most of those don't need the huge sats of the past.
|
| And also people lose perspective. What we have to
| remember is how few launches other large rockets used to
| have. Ariane 5 the commercial success story peaked at 7
| launches.
|
| So yes, new costumers, but not enough to go from 7 to
| 100+.
| actinium226 wrote:
| According to Ashlee Vance's "When The Heavens Went On Sale" this
| was the inspiration for Astra (the book links to this same
| article in the relevant chapter). The company hoped to produce
| and launch >300 rockets a year _without_ re-use. The goal was to
| get economy of scale in manufacturing.
|
| Part of the business plan assumed that people would be using the
| rocket to launch replacement satellites for constellations, and
| so it wouldn't be such a big deal if a rocket failed every now
| and then. This would let them use automotive grade parts in some
| areas as opposed to aerospace grade and reduce costs.
|
| However, it turned out that customers were actually using their
| rocket to launch prototype satellites and other one-off
| satellites where failure was actually a big deal. Long story
| short Astra did manage to make it to orbit, but is unlikely to
| survive into the future.
| looofooo wrote:
| What would another James Webb Telescope would have cost? Far
| far less then the first. Sure it is costly to destroy a
| prototype, but not as much as you think.
| appplication wrote:
| It would have cost less sure, but it would have delayed the
| program years. And such a delay could easily shutter the
| program if political support faltered.
| sitkack wrote:
| In my ideal universe, we have a JWST assembly line.
| blkhawk wrote:
| ...in orbit. Imagine what a device could do you can just
| take a wrench to if it breaks. and how much cheaper you
| could build that.
| actinium226 wrote:
| The companies launch prototypes because they want to test out
| technology and build methods that will go into the production
| satellite. Hence losing the prototype is a huge loss in time
| and/or increase in risk (if they decide to go ahead with
| certain technologies despite lacking on-orbit validation).
| promiseofbeans wrote:
| Isn't Astra developing a reusable launch system now?
| panick21_ wrote:
| Astra is functionally bankrupt. They ain't developing nuting
| anytime soon.
| SCM-Enthusiast wrote:
| they are selling off their assets and focusing on selling
| engine that could be "Reusable". I won't hold my breath.
| panick21_ wrote:
| > Part of the business plan assumed that people would be using
| the rocket to launch replacement satellites for constellations,
| and so it wouldn't be such a big deal if a rocket failed every
| now and then. This would let them use automotive grade parts in
| some areas as opposed to aerospace grade and reduce costs.
|
| Lets be real here. The business plan 'assumed' a whole lot of
| nonsense just so they could claim absurd totally unrealistic
| growth potential. The story shifted to whatever was 'hip' at
| the time.
|
| It very much started with 'cube-sats' are the future. And when
| it was clear this was wrong, they started to make up other
| stuff.
| vl wrote:
| John Walker is also an author of The Hacker's Diet:
| https://www.fourmilab.ch/hackdiet/
|
| While perhaps a bit outdated by modern standards, general
| principles are sound and it's still a very fun read in itself
| since he includes some general reflections in the text.
| joebig wrote:
| The man is also one of the authors of AutoCAD, a mechanical and
| civil engineering drafting software, which is globally popular
| (or hated, depending on who you ask!). I personally love the
| keyboard/commandline integration of AutoCAD, makes for an
| efficient and 'tactile' workflow (compared to the heavy
| dependence on mouse for other CAD software out there).
| flashback2199 wrote:
| Edit: Screw me for sharing facts!
|
| ----
|
| High growth in rocket launches per year would be devastating to
| CO2 emissions at more than an order of magnitude (> 10x) increase
| in CO2 emissions vs airplanes.
|
| With any luck, rockets will remain super expensive, otherwise we
| are going to be pretty screwed.
|
| "A typical long-haul plane flight creates between 1-3 tonnes of
| CO2 per passenger. Rocket launches, on the other hand, generate
| between 50-75 tonnes of CO2 per passenger ... There is no telling
| how large the space tourism industry will become."
|
| https://www.breeze-technologies.de/blog/how-much-air-polluti...
| sabareesh wrote:
| If we can generate Methane for example from CO2 in the
| atmosphere this could potentially solve this problem
| joebig wrote:
| Oxides are incredibly stable chemically. Any further
| conversion or sequestration process is guaranteed by
| thermodynamics to be very energy-intensive.
| wolfram74 wrote:
| we know transitioning to pv/wind is going to lead to some
| months where we've got megawatt-hours coming out of our
| ears. If the only problem is energy cost, that won't be a
| problem long.
| joebig wrote:
| If it takes a day worth of solar/wind to offset a minute
| of rocket emission, then the equivalence is not really
| sustainable.
| Ma8ee wrote:
| The concentration of CO2 is measured in parts per million.
| Just that simple fact make me believe it is very unlikely
| there ever is going to be economical to extract CO2 from the
| atmosphere at any significant scale.
| lkbm wrote:
| There are thousands of long-haul flights--and something like
| 100k flights overall--per day. If we're doing 10k+ rocket
| launches per day, then that's a huge problem. If we're doing 1
| per day, it's a rounding error. This is premature optimization.
|
| (Either way, the solution, of course, is a carbon tax to price
| in the emissions.)
| flashback2199 wrote:
| Edit: I messed up the math - didn't see 100k per _day_ of
| flights...
| wolfram74 wrote:
| one upside is many modern rockets use methane, synthesizing
| methane with pv/wind power would be much lower impact,
| depending on how much of the exhaust is actually at escape
| velocity it could be very slightly carbon negative, like
| new forged steel with ore prepped with clean hydrogen.
| flashback2199 wrote:
| Correct me if I'm wrong but I am under the impression
| that Starship does not use that, the least expensive
| fuels for rockets are highly CO2 emitting, and the least
| expensive fuels are what will get rolled out in mass
| numbers if SpaceX, Blue Origin, and others succeed in
| building a rocket transportation industry.
| avhon1 wrote:
| Starship, Blue Origin's upcoming heavy-lift rocket New
| Glenn, and United Launch Alliance's upcoming heavy-lift
| rocket Vulcan, are all powered by methane and oxygen.
| lacksconfidence wrote:
| starship uses methalox, a combination of methane and
| oxygen. I'm far from an expert, but my understanding is
| the methane comes from refining LNG.
| snewman wrote:
| That's generally where methane comes from today, but in
| time it may come from captured CO2, e.g. see
| https://terraformindustries.com/ (disclaimer: I am a
| minor investor).
| cma wrote:
| Elon said by 2028 they will be in active passenger service
| replacing long haul aviation for cheaper than a business
| class ticket.
| LeifCarrotson wrote:
| That's not realistic simply because of the carbon
| requirements. Long haul aviation only burns a couple
| hundred kg of jet fuel per passenger. (I don't know how the
| top-level comment is calculating 1-3 tonnes of CO2 per
| passenger, Contrail effects? Construction of the plane?
| Altitude? Incomplete combustion? but a 250-passenger 787
| doesn't carry 750,000 kg of fuel, it only fits 100,000 kg
| at most, plus plenty of reserve capacity). The flight only
| costs $100-$200 per person in fuel.
|
| Rocketry is far less efficient than a modern high-bypass
| turbofan.
|
| NASA can afford to buy 75,000 kg of methane per astronaut.
| Even if the rocket was amortized to zero over infinite
| flights, and had zero maintenance costs, even if crew cost
| nothing and airport/spaceport leases cost nothing,
| thermodynamics insists that you still have to buy $100,000
| worth of RP-1 rocket fuel. A business class ticket cannot
| buy enough carbon to support 75,000 kg of emissions.
| bryanlarsen wrote:
| Starship has the size to carry about 400 passengers. Both
| stages together carry about 5,000t of propellant. But
| over 3/4 of that is liquid oxygen, and most of that is
| the first stage. The second stage alone with 1200t of
| propellant can't put humans into orbit, but it does have
| a range comparable to that of a 787. So 300t of liquid
| methane will get 400 passengers about as far as a 787 can
| get 250 passengers with 100t of kerosene.
|
| A starship ticket could theoretically cost <3x the price
| of an airline ticket.
|
| A rocket may be less efficient than a turbofan but it
| gains it back by coasting through space for all but 3
| minutes rather than pushing through air for the entire
| flight.
| pi-e-sigma wrote:
| It doesn't gain anything back, what are you on. Before
| landing it has to shed all the speed it gained that was
| needed for the ballistic trajectory. That energy is lost.
| Orbital or suborbital flights will never, ever be
| competitive to flying with regards to required energy
| expended.
| bryanlarsen wrote:
| It gains _efficiency compared with an airplane_ by
| spending most its trajectory outside of atmosphere with
| no air resistance.
| pi-e-sigma wrote:
| No it does not, because thanks to atmosphere wings on an
| airplane generate lift. And they do it more efficient
| than any kind of engine known to the mankind
| Workaccount2 wrote:
| If I had a list of "Elon said by x we will have y"...
| flashback2199 wrote:
| Just as 100k jet airplane flights per day would have been
| unimaginable in the ~50s when the jet airliner industry
| started, I actually can imagine a near future where many more
| than 10k rockets per day are launched, if the industry has
| it's way and succeeds in reducing costs dramatically.
| actinium226 wrote:
| These are not great comparison numbers. When rockets fly
| passengers it's ~4 people as compared to ~200 for a plane.
|
| A modern 737 has a max fuel load of almost 30000L of jet fuel
| [1].
|
| The density of jet fuel is 775-840 g/L [2]. Let's take 800g/L
| so that we can just multiply the lead numbers - that gives
| 24,000 kg of fuel.
|
| According to spaceflight101 [3], the Falcon 9 uses 123,570 kg
| of RP-1 (similar to jet fuel) in the first stage and 32,300 kg
| of RP-1 in the second stage for a total of 155,870 kg, which is
| about 6.5x the total fuel load on the 737.
|
| Falcon 9 launched 98 times last year (which includes some
| Falcon Heavy flights which have more fuel, but I don't think it
| changes the big picture here).
|
| There are 5000 737's in active service [4]. Most of them are
| probably flying several times per day, but if we just assume
| once per day that's 1,825,000 flights. That's almost 3000x the
| amount of CO2 as produced by all those F9 flights. And that's
| just 737s.
|
| 1. https://en.wikipedia.org/wiki/Boeing_737#Specifications
|
| 2. https://en.wikipedia.org/wiki/Jet_fuel
|
| 3. https://spaceflight101.com/spacerockets/falcon-9-ft/
|
| 4. https://simpleflying.com/boeing-737-in-service-stored/
| flashback2199 wrote:
| Right, I think people are misunderstanding a key point here,
| which is that SpaceX, Blue Origin, etc would really like to
| see rockets be an alternative to airplanes, in which case we
| are talking about a dramatically increased number of
| launches.
| avhon1 wrote:
| > SpaceX, Blue Origin, etc would really like to see rockets
| be an alternative to airplanes
|
| Why? Rockets are intrinsically less efficient and less safe
| than airplanes. Why would they try to compete for use cases
| where they are at such a disadvantage, and where they have
| to-date shown no interest in competing with fixed-wing
| aircraft?
|
| The closest those companies have done to showing interest
| in pitching rockets against aircraft is Elon Musk saying
| that his company will offer ultra-high-speed flights via
| rocket, which is more like a Concorde-killer 25 years after
| the Concorde got killed by its own costs.
| flashback2199 wrote:
| You have answered your own question.
| mkl wrote:
| The article proposes using hydrogen to be carbon-free fuel-
| wise:
|
| > Environmental Issues. One reason for insisting on LH2/LOX
| rather than Kerosene/LOX, hypergolics, or solids/hybrids is
| that it's clean. We could launch one every minute and
| contribute less to global warming, ozone layer depletion, and
| other varieties of atmospheric pollution than 747s crossing the
| Atlantic every day. Also, exhaust and/or fluffy white clouds
| resulting from the occasional really bad day aren't harmful to
| anybody who happens to be downwind.
| orenlindsey wrote:
| Elon Musk probably was inspired by this at some point.
| moritzwarhier wrote:
| At first glance, is this about Keynesian economics for space
| gear? Sorry if this sounds nuts... but it is the best
| paraphrasing I could come up with.
___________________________________________________________________
(page generated 2024-01-05 23:00 UTC)