Nautilus-X

[crazyewok]

I just found this little proposed beauty.

Quite frankly I like it.

Would be a nice step and to me far better for interplanetary transportation than the Dragon capsules or other small capsule designs

What do you think? Dead end or another small step for mankind into our solar system?

http://en.wikipedia.org/wiki/Nautilus-X

http://www.popsci.com/science/article/2011-02/new-nasa-reusable-spacecraft-concept-could-serve-multiple-missions-future

[bigdad84]

It's entirely possible, just one of those things where you have to sit back and wonder... "Where is the money going to come from, to build this."

On another note, I would be really excited to see the demo model of the centrifuge go to the ISS.

[Skyler4856]

Nasa why you no build this?

[rkman]

Not much of a point in building a support vehicle for manned missions if no manned missions are planned.

[K^2]

I would like to see that centrifuge demonstrated first. I have serious doubts about its utility. An accepted range is 2-7 RPM, with rotation bellow 2 RPM believed to be suitable for pretty much everyone, and that above 7 being bad for almost everyone. Since we don't know how long it will take for problems to develop, a long term mission would probably be limited to 4-5 RPM. So that's 10-20% of Earth's gravity that we can count on. I suppose, it's better than none, albeit, at a price of some discomfort. But is that going to be enough to make a difference in a long term mission? It just seems like long term risks outweigh benefits here.

Of course, a lot of this is conjecture, and the rest is based chiefly on Earth-bound studies. So it might be possible to select a crew that will adjust to a higher RPM and get it to a high enough fraction of Earth's gravity to have significant utility. But we really won't know until we try it out on ISS. So I'd definitely push for the demonstration centrifuge on ISS, and wait to see how it goes before pushing for Nautilus-X as a whole.

Also, what a silly acronym. If they do end up developing it, they should have a competition for a better one.

[SargeRho]

.1 to .2g makes a tremendous difference to 0g. Just being pulled "down" will most likely alliviate many of the problems of zeroG, specially the cardiovascular problems.

[K^2]

That's also conjecture. Only ten people have spent any significant amount of time in something like .2G, and we are still talking days, not months or years that Nautilus-X is designed for. We have no idea what the threshold is for developing various health problems associated with microgravity actually is. I'm sure it's better than none, but is it enough to offset any problems that long term exposure of the same cardiovascular to the considerable Coriolis effect?

[Kinglet]

Probably impossible. Concepts are almost never used by space agencies for some reason.

[maccollo]

That's also conjecture. Only ten people have spent any significant amount of time in something like .2G, and we are still talking days, not months or years that Nautilus-X is designed for. We have no idea what the threshold is for developing various health problems associated with microgravity actually is. I'm sure it's better than none, but is it enough to offset any problems that long term exposure of the same cardiovascular to the considerable Coriolis effect?

Why not just bring some mice and a centrifuge small enough to be fitted inside the space station. Then you don't need to bring an entire new module.

It would have three arms, one would be 80 cm, the second arm would be 40 cm and the third 20 cm.

It would rotate at 30 RPM.

This would produce G forces of 0.8, 0.4 and 0.2 G. Each arm would have different ballasts to keep it balanced.

On these different arms you have the mice in their little habitats. 2 or 3 for each, and then one control group that just floats around in 0 G.

Of course the centrifuge contraption would have to be shielded by a cage thing, to make sure it doesn't damage things or hurt the astronauts.

Once this is set up, you let it run for a few months and observe the bone and muscle loss. To me this would seem to be a much more sensible approach than to launch a very expensive new module for the first experiments.

Edited January 6, 2014 by maccollo

[Nibb31]

What you are describing is the abandoned CAM module, which is now rotting on a parking lot in Japan:

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

One of the problems with fitting a centrifuge to the ISS is that the vibrations disturb any other microgravity experiments that might be going on. Another problem is safety and attitude control. The ISS would have to compensate the momentum of the centrifuge by spinning up its CMGs.

In my opinion, CAM was the most drastic and unfortunate cut to the ISS program. Most ISS experiments could be performed on a mini station, but this was one of the only experiments that really benefits from being on a large orbital platform. We know practically nothing about partial gravity, centripetal-induced artifical gravity or the effect of Coriolis forces on living organisms or materials. These are things that we need to learn about before testing larger scale centrifuge modules for BEO spacecraft and before planning long-duration expeditions to Mars or the Moon.

Without this small-scale testing of artificial gravity, there's no point in even thinking about designing a centrifuge into an exploration vehicle, because we simply have no idea whether it is beneficial or not, or how much gravity is needed for it to be beneficial.

The Nautilus-X concept is really just a concept. There is no money behind it and no plans to actually build it. However, NASA is seriously pondering the DSH (Deep Space Habitat) made of 2 ISS modules, which would be combined to Orion, a SEP tug or a cryo upper stage, and maybe the MMSEV. This would give you most of the capability of a manned deep space exploration vehicle:

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

Edited January 6, 2014 by Nibb31

[Scotius]

Hey, DSH looks like a proper exploration vessel Add cluster of VASIMR's and it would make for a nice Mars mothership.

[crazyewok]

.1 to .2g makes a tremendous difference to 0g. Just being pulled "down" will most likely alliviate many of the problems of zeroG, specially the cardiovascular problems.

Plus if its for transporting people to mars it has the advantage of helping the crew to become acustomed to mars gravity.

[crazyewok]

In my opinion, CAM was the most drastic and unfortunate cut to the ISS program. Most ISS experiments could be performed on a mini station, but this was one of the only experiments that really benefits from being on a large orbital platform. We know practically nothing about partial gravity, centripetal-induced artifical gravity or the effect of Coriolis forces on living organisms or materials. These are things that we need to learn about before testing larger scale centrifuge modules for BEO spacecraft and before planning long-duration expeditions to Mars or the Moon.

Maybe one thing I will ever agree with you on.

Centrifuge expeiments to me are far more valuble than microgravity expiremnets.

Just another wasted oppotunity of the ISS, what a big waste of money and potential

[maccollo]

One of the problems with fitting a centrifuge to the ISS is that the vibrations disturb any other microgravity experiments that might be going on. Another problem is safety and attitude control. The ISS would have to compensate the momentum of the centrifuge by spinning up its CMGs.

Alright so, for the sollution (I like solutions):

1: Make it as wide as possible so it can spin as slowly as possible to generate reasonable G forces for the experiment.

2: make sure it's really really well balanced

3: make it a double centrifuge. One spins clockwise, the other one spins counter clockwise, same as on the russian Ka-52 chopper. It has two main rotor blades spinning in opposite directions, and this means it doesn't need a tail rotor.

http://cdn-www.airliners.net/aviation-photos/photos/6/9/8/1576896.jpg

Hey, DSH looks like a proper exploration vessel Add cluster of VASIMR's and it would make for a nice Mars mothership.

Eh... How are you gonna power those Vasimirs to get to Mars in less than several years?

Edited January 6, 2014 by maccollo

[Scotius]

Small nuclear reactor? We will need one anyway sooner or later.

[SargeRho]

I don't think VASIMR is a realistic option for manned spaceflight other than stationkeeping, and won't be for quite a while. It uses huge ammounts of energy, which in turn requires a lot of power generation, which is heavy, negating all the benefits of the ship. The Fusion Driven Rocket would be more viable I think.

[K^2]

Another problem is safety and attitude control. The ISS would have to compensate the momentum of the centrifuge by spinning up its CMGs.

That would generate all sorts of weird torques that aren't good for the structure. The best solution would be for the centrifuge to carry its own counterweight. For a CAM type module, having two counter-rotating centrifuges would probably be the best solution. By canceling angular momentum within the module you save yourself all sorts of trouble. Yeah, I know, added weight, etc, but it's better than risking metal fatigue in some critical structural part holding the station together.

[Skyler4856]

I don't think VASIMR is a realistic option for manned spaceflight other than stationkeeping, and won't be for quite a while. It uses huge ammounts of energy, which in turn requires a lot of power generation, which is heavy, negating all the benefits of the ship. The Fusion Driven Rocket would be more viable I think.

Vasimr is due to launch next year to the station

[Kryten]

Yes, as a test. It's going to be able to be run a few seconds at a time using a capacitor bank, hardly practical for an actual propulsion system.

[maccollo]

That would generate all sorts of weird torques that aren't good for the structure. The best solution would be for the centrifuge to carry its own counterweight. For a CAM type module, having two counter-rotating centrifuges would probably be the best solution. By canceling angular momentum within the module you save yourself all sorts of trouble. Yeah, I know, added weight, etc, but it's better than risking metal fatigue in some critical structural part holding the station together.

I still don't understand why it has to be it's own module? Sure, that would be ideal, but you could easily design something tiny that could go up in pieces inside a soyuz, to be assembled inside an existing module. Sort of like an IKEA experiment kit.

And the thing I suggested certainly wouldn't vibrate more than this.

[SargeRho]

Vasimr is due to launch next year to the station

...Yes, for station-keeping.

[Skyler4856]

...Yes, for station-keeping.

Your original statement stated that vasmir is unable to function in space as of yet.

[K^2]

I still don't understand why it has to be it's own module? Sure, that would be ideal, but you could easily design something tiny that could go up in pieces inside a soyuz, to be assembled inside an existing module. Sort of like an IKEA experiment kit.

If it's a small centrifuge for testing things on rats, yeah, that could work. And that would be useful to try. I think, what they had in mind with CAM would have been quite a bit bigger, and there wouldn't be a good way to assemble it inside an existing module.

[SargeRho]

Your original statement stated that vasmir is unable to function in space as of yet.

It did in no way state that it is unable to function. I said it's unrealistic for anything other than station keeping. I in fact stated that it IS able to function in space, but that it isn't useful for manned spaceflight due to its extreme power cosumption.

[Winter Man]

The Nautilus as far as I remember is primarily a Bigelow project (in terms of who it'll get contracted out to), so it'll probably get launched regardless of NASA funding - someone else'll see the potential.