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They'll still need to verify all systems and components before a second launch That. You need to re-qualify the engine after each launch. The cost of labour

They'll still need to verify all systems and components before a second launch That. You need to re-qualify the engine after each launch. The cost of labour far exceeds the cost of materials, you need to strip and re-build the thing, and you ask yourself just how much money you can save through re-using the first stage. I don't think it's much.

jessriedel 13y ago
> I don't think it's much. SpaceX disagrees. They expect to cut the cost of launch by 1 order of magnitude https://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_development_program#Economic_issues https://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_...
mikeash 13y ago
Unlike NASA's adventures with the space shuttle, SpaceX is a for-profit business with a goal of making money. They wouldn't be pursuing reusability if they didn't think it would increase their ability to make a profit.
cfreeman 13y ago
The Merlin engine was designed from the beginning to be re-useable. They don't have to be "stripped and rebuilt" after each launch. They have already fired engines on the test stand for multiple mission durations with no problems.
oh_sigh 13y ago
So, have you done more analysis on this than SpaceX has? You should send them this post of yours so they stop wasting all that money! I bet they never thought of what you said.
grinich 13y ago
On traditional launch vehicles, yes. Shuttle was definitely this way. And I'm sure SpaceX will initially do a complete disassemble and inspection to gather more data about the wear and tear. But the Merlin engines have been designed from the start to be reusable and dependably reignitable, whether at sea level or upper atmosphere. They're pretty amazing-- essentially the pinnacle of +50 years of engine design. Tom Mueller is a huge badass. :) http://en.wikipedia.org/wiki/Merlin_(rocket_engine) http://en.wikipedia.org/wiki/Merlin_(rocket_engine) And check out that bad boy roar: http://www.youtube.com/watch?v=wkdReoxGHG8 http://www.youtube.com/watch?v=wkdReoxGHG8 I don't have a link on hand, but Elon has said multiple times that the majority cost of the Falcon-9 is the raw material. One of the reasons they've been able to drop the price significantly is by using more efficient manufacturing techniques, requiring less material and creating less waste. (e.g. stir-friction welding) It's also worth noting that Falcon-9 can still complete a mission with one (and perhaps two?) engine failures, which gives quite a more comfortable margin of error. There's a big difference between "perfect" and "near perfect" when it comes to engineering these things. ;)
ef4 13y ago
> you need to strip and re-build the thing That's how politically-designed boondoggles like the shuttle work. It's not inevitable, if you actually spend the engineering effort on reliability and repeatability. If NASA operated an airline, they would probably be tearing down and rebuilding every jet engine after every flight, and a ticket would cost $100,000.
- XorNot 13y ago
  I said this in another thread, but part of the issue is failure intolerance. Sure - for human payloads I'd want to be damn sure my process is good, like, hundreds to thousands of missions deep before I trusted it. But that's totally unnecessary for an unmanned payload! If the cost of launch drops enough, you can fully justify launching 2x the payloads if you expect maybe 1 in 10 failures due to the mode of launch. I suspect it's possible to do a damn site better then that, but for NASA its never been an option. If it's reusable, they can't let a mission fail because they'll only get punished and funded according to the failures, even if they specced everything expecting 1 mission to possibly not go off right.
  - 001sky 13y ago
    This is true for a sub-set of unmanned payloads. Space-X is great for the sub-set of things that don't require insurance, and don't therefore need to use corner-case mil-spec stuff with the corner case pricing. For others, the cost of losing a $1-2B bird on top of a $100m/cheap rocket is shitty math. Nobody is going to insure the top of it, so ultimately the "waste" is akin to a form of insurance. Everybody knows this already, so I'm not sure how sympathetic a hearing it is going to get. It will be great PR though to hopefully spurn <designs> that fit the new framework...and thus expand the market for space-x and hopefully limit the superflous use of corner-case technology for mundane/run-of the mill applications (at the tax payer's expense).
    - rjurney 13y ago
      You really think SpaceX loads aren't insured? This seems impossible.

jessriedel 13y ago

> I don't think it's much. SpaceX disagrees. They expect to cut the cost of launch by 1 order of magnitude https://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_development_program#Economic_issues https://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_...

mikeash 13y ago

Unlike NASA's adventures with the space shuttle, SpaceX is a for-profit business with a goal of making money. They wouldn't be pursuing reusability if they didn't think it would increase their ability to make a profit.

cfreeman 13y ago

The Merlin engine was designed from the beginning to be re-useable. They don't have to be "stripped and rebuilt" after each launch. They have already fired engines on the test stand for multiple mission durations with no problems.

oh_sigh 13y ago

So, have you done more analysis on this than SpaceX has? You should send them this post of yours so they stop wasting all that money! I bet they never thought of what you said.

grinich 13y ago

On traditional launch vehicles, yes. Shuttle was definitely this way. And I'm sure SpaceX will initially do a complete disassemble and inspection to gather more data about the wear and tear. But the Merlin engines have been designed from the start to be reusable and dependably reignitable, whether at sea level or upper atmosphere. They're pretty amazing-- essentially the pinnacle of +50 years of engine design. Tom Mueller is a huge badass. :) http://en.wikipedia.org/wiki/Merlin_(rocket_engine) http://en.wikipedia.org/wiki/Merlin_(rocket_engine) And check out that bad boy roar: http://www.youtube.com/watch?v=wkdReoxGHG8 http://www.youtube.com/watch?v=wkdReoxGHG8 I don't have a link on hand, but Elon has said multiple times that the majority cost of the Falcon-9 is the raw material. One of the reasons they've been able to drop the price significantly is by using more efficient manufacturing techniques, requiring less material and creating less waste. (e.g. stir-friction welding) It's also worth noting that Falcon-9 can still complete a mission with one (and perhaps two?) engine failures, which gives quite a more comfortable margin of error. There's a big difference between "perfect" and "near perfect" when it comes to engineering these things. ;)

ef4 13y ago

> you need to strip and re-build the thing That's how politically-designed boondoggles like the shuttle work. It's not inevitable, if you actually spend the engineering effort on reliability and repeatability. If NASA operated an airline, they would probably be tearing down and rebuilding every jet engine after every flight, and a ticket would cost $100,000.

XorNot 13y ago
I said this in another thread, but part of the issue is failure intolerance. Sure - for human payloads I'd want to be damn sure my process is good, like, hundreds to thousands of missions deep before I trusted it. But that's totally unnecessary for an unmanned payload! If the cost of launch drops enough, you can fully justify launching 2x the payloads if you expect maybe 1 in 10 failures due to the mode of launch. I suspect it's possible to do a damn site better then that, but for NASA its never been an option. If it's reusable, they can't let a mission fail because they'll only get punished and funded according to the failures, even if they specced everything expecting 1 mission to possibly not go off right.
- 001sky 13y ago
  This is true for a sub-set of unmanned payloads. Space-X is great for the sub-set of things that don't require insurance, and don't therefore need to use corner-case mil-spec stuff with the corner case pricing. For others, the cost of losing a $1-2B bird on top of a $100m/cheap rocket is shitty math. Nobody is going to insure the top of it, so ultimately the "waste" is akin to a form of insurance. Everybody knows this already, so I'm not sure how sympathetic a hearing it is going to get. It will be great PR though to hopefully spurn <designs> that fit the new framework...and thus expand the market for space-x and hopefully limit the superflous use of corner-case technology for mundane/run-of the mill applications (at the tax payer's expense).
  - rjurney 13y ago
    You really think SpaceX loads aren't insured? This seems impossible.