A Look at Space Stations That Never Were

[pokerfan]

The International Space Station​ is about to start its 11th year of continuous human habitation. Here is a look at designs for an orbiting outpost that didn't make it off the drawing board

Space stations started out as any other technology does before it becomes a reality—as concepts. In the past century engineers, writers and even movie producers have created conceptual space stations that ranged from simple orb-shaped structures to elaborate multi-unit designs. The imaginations of innovators who dreamed deeply about humans living in space are featured in the following nine artists' representations.

http://www.scientificamerican.com/article.cfm?id=space-station-drawings

[sakabatou]

1. Welcome to the Brick Station!

[tridim]

2. I still like the idea of using the shuttle liquid fuel tanks for habitation

Too late now.

Apparently it wouldn't have been all that difficult to keep them in orbit instead of letting them fall to back Earth. There were plans to put them together into a ring to use as a space station. It just never happened.

[pokerfan]

3. Such a waste

But then again, everything associated with the shuttle program was wasteful. Each launch, all that mass sent into orbit at tremendous expense only to bring 80% of it back. :crazy:

But yeah, the External Tanks could have been carried into orbit at some small reduction in Orbiter payload capacity. At the time the ET is jettisoned, it has 97% of orbital velocity.

STS-121 ET falling back to Earth: http://youtu.be/rFp2mxbKLcY

The ETs were huge. Roughly the height of an 11 story building. A single ET had roughly 2.5X the volume of the current ISS. Kim Stanley Robinson used a bunch of them to assemble a Mars colonization ship in the novel, Red Mars:

[TheMadMonk]

8. Actually it COST lift capacity to ensure the ET did not end up in orbit.

Early plans may well have been to use ETs, I suspect the contractors put an end to that.

[pokerfan]

10. I was not aware of that

Where does the last 3% of the delta-V required for LEO come from? In any case, it's certainly moot at this point. Here's a study (pdf) NASA put together back in 1983: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940004970_1994004970.pdf Fun reading.

[TheMadMonk]

12. Recall the smaller motors near the main motors? Thems.

Part of the OMS.

Fun reading and I'm coming to suspect, absolutely moot since about '63 if not earlier. NASA only does science as an excuse for the government behind it to play politics and wargames.

Methinks Space-X is the USA's last shot at being a space power and the direction it's "masters" are taking makes me very pesimistic on that front. If I were to bet, it would be on China and/or India.

[pokerfan]

13. I guess, if there's enough margin in the fuel for the OMS

It still represents dead weight and if you had enough fuel to carry the ET all the way to orbit then you also had enough fuel to carry more payload. Look, I'm not arguing against it. I was very much in favor it. I'm just saying that it's not free. Rockets have stages for a reason.

My money's on China to eclipse both the US and Russia and probably sooner than anyone expects.

[TheMadMonk]

14. The necessary fuel is discarded along with the tank.

And any possible threat to expensive solutions from space contractors.

With the tanks, the only things that would have to be transported would be interconnect hardware and a whole bunch of mostly off the shelf componentry, with almost zero room for padding the billvalue adding.

[bananas]

15. IIRC, they didn't want a lot of space junk that could endanger future missions

They thought they might be launching two shuttles a week,
it wouldn't take long for thousands of boosters to be flying around,
possibly resulting in a chain reaction destroying anything in LEO:

http://en.wikipedia.org/wiki/Kessler_syndrome

The Kessler syndrome (also called the Kessler effect,<1><2> collisional cascading or ablation cascade), proposed by NASA scientist Donald J. Kessler in 1978, is a scenario in which the density of objects in low Earth orbit (LEO) is high enough that collisions between objects could cause a cascade – each collision generating debris which increases the likelihood of further collisions.<3> One implication is that the distribution of debris in orbit could render space exploration, and even the use of satellites, unfeasible for many generations.<3>

<snip>

To minimize the chances of damage to other vehicles, designers of a new vehicle or satellite are frequently required<6> to demonstrate that it can be safely disposed of at the end of its life, for example by use of a controlled atmospheric reentry system or a boost into a graveyard orbit.<7>

<snip>

[bananas]

16. IIRC, NASA was willing to give away the boosters for free to anyone ...

as long they as they were willing to be responsible for them...
which included things like:
- paying fair share of 24/7 radar monitoring for collision avoidance
- paying for upkeep of manouvering thrusters to avoid collision
- paying insurance to cover damages from the inevitable collisions with other satellites

Nobody was interested enough to pay the costs, so NASA did the responsible thing and de-orbited them.

[DetlefK]

4. You do know that some fuels are poisonous or cause cancer?

Just take http://en.wikipedia.org/wiki/Hydrazine for example.

How are the astronauts supposed to scrub the fuel tanks clean in space?

[tridim]

5. It's a problem that could have been solved.

I'm not even sure the hydrazine was stored in the big tank, the primary fuel was liquid oxygen.

[caraher]

6. The external tank didn't carry toxic fuels

It was hydrogen in one part and oxygen in the other. Hydrazine and other chemicals used as hypergolics are for the attitude control thrusters in the Orbiter. And of course, the solid fuel boosters had an entirely different set of fuels... but those get jettisoned well short of orbital speed and were re-used in any case.

[TheMadMonk]

7. Hydrogen and Oxygen. Neither poison nor carcinogen. /nt

[sofa king]

17. The big fuel tank was just water waiting to be.

Hydrogen and oxygen, is all, combining into water with a thunderous roar. I think in theory one could clean out the tanks themselves by simply connecting the two tanks together, letting them slowly circulate and react during the normal orbital heating and cooling cycle, and then drinking the result (after reaching orbit, the fuel densities should be far too low to actually explode).

As far as I know, the main tank had no nasty hypergolic maneuvering systems or APUs or anything like that. The main tank did have a large strip of detcord-like explosive material running along it, so the range safety officer could blow the whole thing in an emergency. For awhile it was thought that the O-ring failure on Challenger may have touched off the range-safety explosives, but I believe that idea was eventually discounted.

That system, obviously, would have to be disabled and removed, unless one was clever enough to use the mission-abort system as the solid propellant for the final boost to orbit--a level of recycling that did not meet NASA's marketing requirements at the time, and which probably gives every engineer reading this the willies: there are rockets, and there are explosives, and when humans are aboard, one system probably ought not play both roles.

It's a damn shame that we did not collect those wonderful things in LEO for storage, habitation, and deep-space missions. I might be living in one now if we had.

[hunter]

9. What's with the Pinocchio nose on that station?

A nuclear reactor maybe? I don't see any solar panels.

[pokerfan]

11. Yeah, probably a reactor

Seems silly, sort of like bringing sand to beach, but there it is.