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I wonder if instead of letting the second stage burn up, they could dock them in space somewhere to serve as material and fluid storage. They might not work fo

I wonder if instead of letting the second stage burn up, they could dock them in space somewhere to serve as material and fluid storage. They might not work for long term cryogenic storage, but a ton of pure aluminum has to be worth something up there.

Tuna-Fish 12y ago
They launch to specific orbits desired by the customers. It might well be extremely expensive to move the second stage from these orbits to some common one where could dock.
- toomuchtodo 12y ago
  Yes, definitely cost prohibitive from a fuel perspective to change orbits, but the vehicle could be safed for future use. I do not have enough information as to whether though would be valuable unless Tesla as some way to produce fuel on-orbit for the waiting, safed second stages.
  - TeMPOraL 12y ago
    Well, FWIW, it works in Kerbal Space Program. But as you said, this would require for the fuel to be brought from somewhere else than Earth's gravity well. Maybe Planetary Resources will find some kerosene on a near-Earth asteroid?
    - lmm 12y ago
      No it doesn't, not if you launch satellites where customers want them. Kerbal Space Program should really bring home the big fundamental about orbital mechanics: plane changes are really expensive.
      - TeMPOraL 12y ago
        There are ways to make plane changes cheap (do them high enough, use gravity assist, etc.) and they could be useful when shipping fuel higher from Earth's gravity well, but I admit, current space missions are nowhere near that complicated. Also, while expensive, plane changes are still cheaper delta-V-wise than punching through the soup our atmosphere is.
  - NamTaf 12y ago
    You'd have to keep boosting it where it is, which means it needs extra thrusters. Otherwise it'll just decay. Also, changing orbits is expensive. Remember you need to change both height and angle, and the delta-V is huge. Bringing them back down is almost certainly the easiest option.
    - ansible 12y ago
      If the 2nd stage at least had a small solar panel and magnetic tether, it could (slowly) change orbits into something useful. Not sure what the weight penalty for a minimally viable system would be. For the 2nd stage, every gram counts, much more so than for the 1st stage.
- stcredzero 12y ago
  If we could fuel tugs with material from off-planet, then it wouldn't be nearly as expensive to do this.

Tuna-Fish 12y ago

They launch to specific orbits desired by the customers. It might well be extremely expensive to move the second stage from these orbits to some common one where could dock.

toomuchtodo 12y ago
Yes, definitely cost prohibitive from a fuel perspective to change orbits, but the vehicle could be safed for future use. I do not have enough information as to whether though would be valuable unless Tesla as some way to produce fuel on-orbit for the waiting, safed second stages.
- TeMPOraL 12y ago
  Well, FWIW, it works in Kerbal Space Program. But as you said, this would require for the fuel to be brought from somewhere else than Earth's gravity well. Maybe Planetary Resources will find some kerosene on a near-Earth asteroid?
  - lmm 12y ago
    No it doesn't, not if you launch satellites where customers want them. Kerbal Space Program should really bring home the big fundamental about orbital mechanics: plane changes are really expensive.
    - TeMPOraL 12y ago
      There are ways to make plane changes cheap (do them high enough, use gravity assist, etc.) and they could be useful when shipping fuel higher from Earth's gravity well, but I admit, current space missions are nowhere near that complicated. Also, while expensive, plane changes are still cheaper delta-V-wise than punching through the soup our atmosphere is.
- NamTaf 12y ago
  You'd have to keep boosting it where it is, which means it needs extra thrusters. Otherwise it'll just decay. Also, changing orbits is expensive. Remember you need to change both height and angle, and the delta-V is huge. Bringing them back down is almost certainly the easiest option.
  - ansible 12y ago
    If the 2nd stage at least had a small solar panel and magnetic tether, it could (slowly) change orbits into something useful. Not sure what the weight penalty for a minimally viable system would be. For the 2nd stage, every gram counts, much more so than for the 1st stage.
stcredzero 12y ago
If we could fuel tugs with material from off-planet, then it wouldn't be nearly as expensive to do this.