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The shuttle is in no way comparable with the SpaceX solution. The shuttle was notoriously slow for turn around because it was a massively complicated machine t

The shuttle is in no way comparable with the SpaceX solution. The shuttle was notoriously slow for turn around because it was a massively complicated machine that had to be man-rated. A Falcon 9 first stage is a much simpler machine. On top of that, the shuttle had to go through re-entry, with all of the G forces, and thermal shock associated with that. The Falcon 9 first stage has neither of these problems.

alexggordon 12y ago
Exactly. SpaceX has completely designed this rocket around easy readiness tests. That's why the rocket was switched from a parachute landing, to a VTOL device[0]. They basically want this to be a smart rocket. Something that can just launch payloads into and out of orbit, and come home like a good dog after a long day of work. [0] http://en.wikipedia.org/wiki/Falcon_9#Reusability http://en.wikipedia.org/wiki/Falcon_9#Reusability
- smackfu 12y ago
  Well, either they tear apart and inspect the engine in between launches or they don't. If they don't, their turnaround will be way faster, but there is a greater chance of failure, and if there is a failure, a much lower chance of figuring out the reasons.
  - simonh 12y ago
    The engines are fired up, shut down and then re-lit again for many dozens of cycles during testing. Plus it's re-started 3 times during landing manoeuvers on top of the launch burn, so it's definitely capable of re-use without being stripped and cleaned. How many times I don't know, but like I said they run the engines though a lot of cycles during testing so they should have a good handle on that.
    - grecy 12y ago
      > so it's definitely capable of re-use without being stripped and cleaned. How many times I don't know I'm confident SpaceX themselves would have tested multiple engines to failure with many, many re-light, shutdown, re-light cycles so they have a good understanding of what's going to happen when they try to re-use one of these things. There is no way they'd be going to all this trouble to design a rocket that can come back, all the trouble of giving it someplace to land if they were not already confident the engine can be used at least a few times.
      - smackfu 12y ago
        OTOH, there's still huge cost savings even if you need to take apart and reinspect the engines. Building space components is not cheap.
jcoby 12y ago
The Falcon 9 still has to deal with heat cycles, vibration, and soot/chemicals byproducts from the engines. The heat cycles and vibration lead to work hardening and cracking or softening of components. Soot can and will get into everything and destroy bearings and connectors. Even the spray from the ocean combined with the heat from the latent heat in the craft can lead to accelerated corrosion. They're shooting for a final touchdown speed of 2m/s which seems fairly slow but that's still a lot of mass to stop very quickly. The ocean helps soften touchdown for sure. It would not surprise me if the turn around procedure was to r&r the entire bottom third of the craft and (possibly) the fuel tanks. The removed components could get inspected and rebuilt and flown again. It won't be anywhere near the scale of the shuttle turn around but it won't be as simple as hosing it off and fueling it up. SpaceX has of course considered all of these things and it will be an amazing thing for space travel if they pull it off.
- Crito 12y ago
  > Even the spray from the ocean The ultimate goal is to land at least most of the cores on land, not the barge, in part to avoid this.

alexggordon 12y ago

Exactly. SpaceX has completely designed this rocket around easy readiness tests. That's why the rocket was switched from a parachute landing, to a VTOL device[0]. They basically want this to be a smart rocket. Something that can just launch payloads into and out of orbit, and come home like a good dog after a long day of work. [0] http://en.wikipedia.org/wiki/Falcon_9#Reusability http://en.wikipedia.org/wiki/Falcon_9#Reusability

smackfu 12y ago
Well, either they tear apart and inspect the engine in between launches or they don't. If they don't, their turnaround will be way faster, but there is a greater chance of failure, and if there is a failure, a much lower chance of figuring out the reasons.
- simonh 12y ago
  The engines are fired up, shut down and then re-lit again for many dozens of cycles during testing. Plus it's re-started 3 times during landing manoeuvers on top of the launch burn, so it's definitely capable of re-use without being stripped and cleaned. How many times I don't know, but like I said they run the engines though a lot of cycles during testing so they should have a good handle on that.
  - grecy 12y ago
    > so it's definitely capable of re-use without being stripped and cleaned. How many times I don't know I'm confident SpaceX themselves would have tested multiple engines to failure with many, many re-light, shutdown, re-light cycles so they have a good understanding of what's going to happen when they try to re-use one of these things. There is no way they'd be going to all this trouble to design a rocket that can come back, all the trouble of giving it someplace to land if they were not already confident the engine can be used at least a few times.
    - smackfu 12y ago
      OTOH, there's still huge cost savings even if you need to take apart and reinspect the engines. Building space components is not cheap.

jcoby 12y ago

The Falcon 9 still has to deal with heat cycles, vibration, and soot/chemicals byproducts from the engines. The heat cycles and vibration lead to work hardening and cracking or softening of components. Soot can and will get into everything and destroy bearings and connectors. Even the spray from the ocean combined with the heat from the latent heat in the craft can lead to accelerated corrosion. They're shooting for a final touchdown speed of 2m/s which seems fairly slow but that's still a lot of mass to stop very quickly. The ocean helps soften touchdown for sure. It would not surprise me if the turn around procedure was to r&r the entire bottom third of the craft and (possibly) the fuel tanks. The removed components could get inspected and rebuilt and flown again. It won't be anywhere near the scale of the shuttle turn around but it won't be as simple as hosing it off and fueling it up. SpaceX has of course considered all of these things and it will be an amazing thing for space travel if they pull it off.

Crito 12y ago
> Even the spray from the ocean The ultimate goal is to land at least most of the cores on land, not the barge, in part to avoid this.