Shuttle fuel tanks 1

[johnd307]

Why do we not carry some of the large fuel tanks into low orbit to be used as part of ISS or the like? It would seem more economical than letting them burn up on reentry each time.

 

[IRstuff]

Gee, how big a rocket would you need for that???????

TTFN

 

[Retracnic]

Though the task of parking the 58,000 lb (dry weight assuming Super Lightweight model) shuttle external tank on low earth orbit is quite achievable, I don't think it's quite the economic windfall that some do.

A good resource you might want to check out is at:

http://www.space-frontier.org/Projects/ExternalTanks/

Good Luck
Bryan Carter

 

[IRstuff]

Sorry, misread, thought you wanted the fuel in orbit.

As for cannibalizing a fuel tank, only if you're truly desperate. The shuttle tank outer skins are not vaccuum tight and were never meant to be. The inner tanks would require cutting to get doors, etc in them. There is no wiring or structural supports necessary for use in a space station or other application. It would be a monumental job to re-fit it for something else.

TTFN

 

[Compositepro]

You pose a good question which occurs to eveyone who thinks about it. The answer is the same as why are rockets built in multiple stages rather than one. Fuel tanks are weight that subtracts from payload weight. The other factor you may not realize is that the shuttle only flies to low earth orbit. It carries satelites with booster rockets to get them to higher orbits.

If the goal were to get large cylinders into orbit to use for a space station then using the fuel tanks would be energy efficient. It has been considered. But converting a cryogenic tank into living quarters while in orbit is not trivial. One day it may be done, but not with the Space Shuttle.

 

[dpc]

Actually, I don't think we'll ever see another shuttle launch that carries a satellite with a booster rocket in the payload bay.

I'd be surprised if we ever see another satellite launched from the shuttle at all.

Expendable fuel tanks do seem wasteful, but at a total cost of about $500 million per launch, it may not be a major cost component. They should spend the money finding a way to keep the @#$%#$ foam from falling off.

 

[CusterWilson]

I WOULD DO THIS.

... the reason is: Dead weight, as a counterweight, allows a "mini-Shuttle" (MAKS, Pioneer, Space Van) to use a tether ... Space Van, for instance, is a reusable Delta/Centaur adaptation designed 20 years ago with a payload of about 1500 pounds ... plus or minus 2000. The latter fact is WHY these things do not get Bank backing.

But a tether, adding 5000 pounds, does not JUST make more payload, but wipes out the considerable risk of getting, well ... negative cargo.
You need about a dozen ETs.

The loss of Shuttle cargo is considerable, especially for (Space) Station as the orbit is higher than where the ET is normally ditched (if I remember, about 3-4,000 lb.) -- plus you would want it in a HIGHER orbit than Station, so you would want a small engine, partly using residual gas in the Tank (840 lb Oxygen alone).