Author Topic: Reusability effect on costs  (Read 147469 times)

Online Robotbeat

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Re: Reusability effect on costs
« Reply #220 on: 10/22/2016 07:21 PM »
Maybe they are at the realization NOW that their methane based architecture is needed, but looking back I don't think it's fair so say that was their plan all along (see the original, full reuse F9 and associated quotes):
http://www.popularmechanics.com/space/rockets/a7446/elon-musk-on-spacexs-reusable-rocket-plans-6653023/
Indeed. A fully reusuable F9 seemed to be the plan up till around 2014. I'd love to know what SX have learned that turned that around. :(
That's the same time ITS started to be formulated. I suspect a lot of it was that they realized they really wanted to move to methane long term because of the lack of coking. I don't think kerosene can ever be as fast turnaround as methane due to kerosene's coking requiring some cleaning. They decided not to do a rocket using both methane and kerosene for handling simplicity and because a methane stage really wants to be bigger.

For LEO, they would definitely have enough performance for a reusable upper stage, especially for Falcon Heavy. But you can improve costs even more if you have a single core vehicle that's fully reusable and uses a propellant that enables rapid reuse (i.e. No major coking). I don't think ITS will be the only methane rocket they build long term.
« Last Edit: 10/22/2016 07:29 PM by Robotbeat »
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Offline Pipcard

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Re: Reusability effect on costs
« Reply #221 on: 10/22/2016 07:58 PM »
If a single core fully reusable FH is so much better/simpler operationally than a three-core of an equivalent capacity, should SpaceX have developed a suborbital reusable test vehicle akin to New Shepard, or a reusable Falcon 1, to test out the viability of maintaining reusable engines vs expending them, then go straight to an FH-class single core launcher like New Glenn?

Or was going for the single/triple-core family the right decision at the time? With the consideration of lower flight rates (i.e. today's), a partially reusable launcher (with expendable upper stage) would be more viable because of the higher payload penalty and development costs of upper stage reuse, but the expended upper stage would be oversized for smaller payloads if it were a single core 50 tonne launcher. The idea of being oversized will not matter with full reuse, but that requires higher launch rates and demands than today.
« Last Edit: 10/22/2016 08:08 PM by Pipcard »

Online Prettz

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Re: Reusability effect on costs
« Reply #222 on: 10/22/2016 11:05 PM »
SpaceX could not have gone with a wider rocket than Falcon 9 regardless, so it doesn't matter. Without road transportability, that blows away the initial plan for low costs and high flight rate.

Offline Pipcard

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Re: Reusability effect on costs
« Reply #223 on: 10/22/2016 11:23 PM »
Musk said in the infamous Q&A section of his ITS presentation that the booster and spaceship, too large for road transportability, might be manufactured among "multiple states," and that's he's considering Louisiana (Michoud) as one of them. So that point may be moot.

Or what about just building the wider rocket near the launch site?
« Last Edit: 10/22/2016 11:39 PM by Pipcard »

Online Prettz

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Re: Reusability effect on costs
« Reply #224 on: 10/22/2016 11:40 PM »
I thought you were talking about instead of making F9 and FH.

Offline Pipcard

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Re: Reusability effect on costs
« Reply #225 on: 10/22/2016 11:46 PM »
I thought you were talking about instead of making F9 and FH.
I am still talking about alternate history; I was using Musk's statement as an example.

Online Robotbeat

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Re: Reusability effect on costs
« Reply #226 on: 10/23/2016 12:41 AM »
FH is still probably a better approach for them even if they had a "do-over." Road transportability is a big problem, and would've meant SpaceX wouldn't have built a factory in the middle of LA, which had a bunch of cheap facilities at the time SpaceX was building out their factories and a large labor pool of aerospace workers and also all the other advantages of being in an actual, real city. And SpaceX wants to do polar as well as equatorial and ISS launches plus testing in McGregor (a facility which they got CHEAP with an included huge test stand which they used for their many initial flights), which means they would have to transport stages a lot, and road is still the best way to do that if you can manage it. And they were operating expendably for a long time, since they hadn't yet discovered/invented practical reuse concepts, so that meant transporting every stage for every flight, probably multiple times: from factory near/in a big city to somewhere in the boonies to test--McGregor being great because it was so cheap and already built--and then to a coast to launch.

SpaceX's ITS only needs equatorial for its main mission, and probably can't be tested in McGregor anyway. And it will be fully reusable from the start, so once built and acceptance testing (we don't yet know where for either of those things), it doesn't need to be moved to a new launch site each launch. But they couldn't have done this at first, because they were necessarily operating expendably. So no, I don't think it'd make sense for them to have chosen a bigger diameter. Things COULD'VE gone differently, but it's definitely not a mistake that they went the way they did. It was pretty strongly determined.

Blue Origin is having to build a factory in Florida. They claim to not want to enter the DoD market or otherwise directly compete with ULA, so they don't need polar launch. They can get by with one launch site, and so road transportability is not an issue for them. Especially since they seemed to have finally gotten a handle on a reasonable reuse method that should work nearly off the bat (they have their experience from New Shepard and can draw on some lessons from SpaceX, too), and anyway, they probably can't afford to operate expendably like SpaceX.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline envy887

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Re: Reusability effect on costs
« Reply #227 on: 10/24/2016 03:51 AM »
F1 is too small and FH too big for most payloads today. F9 is basically perfect in size and much better suited for SpaceX operations flows.

Offline john smith 19

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Re: Reusability effect on costs
« Reply #228 on: 10/24/2016 08:31 AM »
F1 is too small and FH too big for most payloads today. F9 is basically perfect in size and much better suited for SpaceX operations flows.
Which is why I'm sceptical about the argument that upping the payload size lowers the $/lb price only if you can use the full payload.

People forget SX were talking an F3 and an F5 after the F1 but they both went away when they found no market for intermediate sizes.
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.
So you're going to Mars to seek a better life. What does that mean to you? Always spot a fanbois by how they react to their idols failures.

Online Robotbeat

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Re: Reusability effect on costs
« Reply #229 on: 10/24/2016 11:59 AM »
there was a market for F5. Just that there was a larger one for F9 and they could also launch F5 payloads on F9. Heck, they launched F1 payloads with F9.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline rsdavis9

Re: Reusability effect on costs
« Reply #230 on: 10/24/2016 12:14 PM »
there was a market for F5. Just that there was a larger one for F9 and they could also launch F5 payloads on F9. Heck, they launched F1 payloads with F9.

Doesn't the same apply to BFR/BFS.
It can launch anything and if fully and rapidly reusable should be (very) cheap.
So if launches a small payload the excess capacity/space will be filled with something.
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
Same engines. Design once. Same vehicle. Design once. Reusable. Build once.

Offline john smith 19

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Re: Reusability effect on costs
« Reply #231 on: 10/24/2016 06:05 PM »
there was a market for F5. Just that there was a larger one for F9 and they could also launch F5 payloads on F9. Heck, they launched F1 payloads with F9.

Doesn't the same apply to BFR/BFS.
It can launch anything and if fully and rapidly reusable should be (very) cheap.
So if launches a small payload the excess capacity/space will be filled with something.
It's cheap in $/lb if the extra payload is used by someone else.

Otherwise you just bought a very oversized launcher to send up a small payload.  :(

"It's only X $/lb if you use FH" still needs an absolute cost several x bigger than the F9.

I'm interested in low $/lb at a payload size people can fully use.


"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.
So you're going to Mars to seek a better life. What does that mean to you? Always spot a fanbois by how they react to their idols failures.

Offline Arb

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Re: Reusability effect on costs
« Reply #232 on: 11/16/2016 05:29 PM »
A couple of recent documents have just been listed on NTRS that may be of interest to readers of this thread.  One is a conference paper and the other is the presentation slides that accompany it.

Is It Worth It? - the Economics of Reusable Space Transportation

Abstract
...
Abstracts usually include the conclusion; this one is pure tease (and long-winded at that). Would someone who's read the papers kindly provide a TL:DR. Many thanks.

Online Semmel

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Re: Reusability effect on costs
« Reply #233 on: 11/16/2016 07:36 PM »
I wanted to spare my time and looked at the presentation. I am not impressed, its on exactly the same level of insight as we have established within this very forum already. Is this type of explanatory power common for economics papers? I am only used to computer science and astronomy papers. Such a content would never be accepted for any publisher I know. The conclusion "It depends" is a tautology and always valid. And it doesnt even explore the variables it depends on. It doesnt come with an economic model. It doesnt have any predictive power. You cant make any decision based on the presented information. Sorry to give it such a harsh review, but this is just not worth the time to read. No new insights expected.

Offline john smith 19

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Re: Reusability effect on costs
« Reply #234 on: 12/01/2016 09:06 AM »
Sorry to give it such a harsh review, but this is just not worth the time to read. No new insights expected.
I've skimmed it.

Lots of chaff with a few grains of wheat in here.

Actually discusses price elasticity and does do a DCF on a simplistic model of an RLV. The pareto analysis is also interesting. Top 3 items on the Atlas are "Systems engineering & prgramme management, 1st stage engine, launch and mission operations." IOW 2 of these, making up about 34% of the whole mission cost, are not physical at all. This suggests there is significant scope for improvement in these items.

Beyond that.
You could cut half the words and still be left with a coherent paper. Also note this company was involved in the X33/Venturestar programme.  :( Also note the comment on page 9

"Some apologists for investment in reusable systems predict potentially important benefits to humankind if reusable transportation reduces the cost of access to space to such a significant degree that space is opened up to ever more, as yet untapped uses. "

I guess that would include Elon Musk and Jeff Bezos in the list of "apologists."

Apparently this is part of a training course from the "International Cost Estimating and Analysis Association."

Not impressed.  :(
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.
So you're going to Mars to seek a better life. What does that mean to you? Always spot a fanbois by how they react to their idols failures.

Online Jet Black

Re: Reusability effect on costs
« Reply #235 on: 12/01/2016 11:38 AM »
there was a market for F5. Just that there was a larger one for F9 and they could also launch F5 payloads on F9. Heck, they launched F1 payloads with F9.

Doesn't the same apply to BFR/BFS.
It can launch anything and if fully and rapidly reusable should be (very) cheap.
So if launches a small payload the excess capacity/space will be filled with something.

That really depends on whether you can get enough compatible payloads that want to go into compatible orbits at the same time.
For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled. -- Richard Feynman

Offline rsdavis9

Re: Reusability effect on costs
« Reply #236 on: 12/01/2016 12:06 PM »

Quote
Doesn't the same apply to BFR/BFS.
It can launch anything and if fully and rapidly reusable should be (very) cheap.
So if launches a small payload the excess capacity/space will be filled with something.

That really depends on whether you can get enough compatible payloads that want to go into compatible orbits at the same time.
for geosynchronous they are all compatible. Same altitude, same inclination. A slighter lower orbit will rotate around to the correct position. It can take as little delta-V as you like.
With ELV best efficiency was the paradigm. The new paradigm is reusable, good enough, and commonality of design.
Same engines. Design once. Same vehicle. Design once. Reusable. Build once.

Offline deruch

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Re: Reusability effect on costs
« Reply #237 on: 12/02/2016 03:55 AM »
I guess that would include Elon Musk and Jeff Bezos in the list of "apologists."
Note, "apologist" in this context is not a perjorative usage but merely describing someone who offers arguments in support of a position/idea.
Shouldn't reality posts be in "Advanced concepts"?  --Nomadd

Offline JamesH65

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Re: Reusability effect on costs
« Reply #238 on: 12/02/2016 10:10 AM »
I guess that would include Elon Musk and Jeff Bezos in the list of "apologists."
Note, "apologist" in this context is not a perjorative usage but merely describing someone who offers arguments in support of a position/idea.

It also implies there is something to apologise for, which I do not think is the case. It's the wrong word.

Offline allhumanbeings07

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Re: Reusability effect on costs
« Reply #239 on: 12/02/2016 10:33 PM »
I guess that would include Elon Musk and Jeff Bezos in the list of "apologists."
Note, "apologist" in this context is not a perjorative usage but merely describing someone who offers arguments in support of a position/idea.

It also implies there is something to apologise for, which I do not think is the case. It's the wrong word.

It's a completely neutral term for describing the nature of someone's position in a debate, and used exactly how it should be here... is it *wrong* for physicists to say that quarks have colors if they don't mean what the most common definition of color means? Is it *wrong* for us to say that rockets have stages if that causes someone who knows nothing about rockets to wonder where the actors are?
I love Star Trek more than anyone, but we don't (and shouldn't) spend tens of billions of dollars on space programs for fun

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