just wondering (space shuttle)

[VJ]

Why have they returned Atlantis to earth? Couldn't they have kept it attached to the ISS and "redocorate" it? I mean it has a very big cargohold, surely this could be useful either as living quarters or as a work place to fix or store things?

I assume there must be some reason, but any thoughts on why this was not done? (I don't know if they considered it)


Jörg

[Dr Mordrid]

The shuttles fuel cell power system only lasts 2 weeks and cannot be re-fueled in space, plus it would take 4 3-person (2 passengers + 1 pilot) Soyuz flights to bring home 7 astronauts. Cost of passenger return on Soyuz: $50 million per seat, and it's due to go up. Do the math.

The shuttle cargo hold is for un-pressurized cargo only and has no life support system, radiation or micro-meteoroid shielding and therefore it can't be used as habitable volume or for storing anything that would be damaged by the vacuum or deep cold. It and the robotic arm also need power from those un-refuelable fuel cells. Oops.

Sending up a Bigelow BA-330 (330 cu/m) habitat would be far better since they are designed for habitation, have full life support and a 'safe' room in case of fire. They can also be fit with water blankets in the walls as radiation shields. That's why NASA has preparing for that option in the 2011 NASA budget.

Bottom line is that the shuttle is 40+ year old technology, albeit with some improvements, and wasn't even supposed to be flying past 1990-1995.

By now we were supposed to have a second shuttle for crew only, the HL-20 which is now in private development as the Sierra Nevada/SpaceDev Dream Chaser, a heavy lifter based on the shuttle fuel tanks, engines and SRB's known as Shuttle C and real deep space spacecraft. We were also supposed to have inflatable habitats for use in space stations, deep space manned spacecraft and as fuel depots, but they too are now in private hands @ Bigelow.

Congress and misguided NASA management canceled them all, and if it weren't for private NewSpace companies picking up the ball and running with it we'd never get them at all. As for Shuttle C, an eminently practical design, NASA still has their thumb up their backside deciding if they'll build it or start a new design from scratch.

IMO by the time NASA decides what to build as a heavy lifter either a NewSpace company like SpaceX or an OldSpace outfit like ULA will come up with one of their own.

Already on the roadmap - SpaceX's Falcon 9 Heavy H is estimated to be able to loft a city bus-sized payload of about 50 mT, so 2 launches could easily handle the payloads of a Saturn V class launcher, and they have plans for something much larger using Merlin engines the same size as the Saturn V's F-1 (1.5 million lbs of thrust each). ULA could also decide to build the Atlas V Heavy Phase 3, which could loft about 70 mT each.

[VJ]

Thanks for the explanations!

Indeed, it would be too difficult to "redecorate" it, especially with better alternatives soon becoming available.