Possible Gravity on spacecraft

[frankm134]

what would the most possible way to make artificial gravity on a space craft. I have heard if an object is spinning fast enough it can create some gravity. like a centrifuge, is this plausible?

[peadar1987]

To save mass and complexity, I'd avoid a centrifuge and attach the hab module for a long space trip to the spent upper stage from the final burn with a tether, and use it as a counterweight. 200m of UHMW Polypropylene weighs far less than making a 200m centrifuge. According to wiki, smaller centrifuges run into problems with the Coriolis effect, and people can't adjust to living in them for extended periods.

[Nibb31]

Artificial gravity is not necessary for any mission profile in the foreseeable future.

[Mr Shifty]

Artificial gravity is not necessary for any mission profile in the foreseeable future.

I suspect it would actually be a pretty high priority for any Mars mission that involved a crewed landing (Polykov's walk from spacecraft to lawn chair notwithstanding.) I'm not sure what your horizon for "the foreseeable future" is, but a crewed Mars mission seems at least plausible for sometime in the next 50 years.

[SargeRho]

Artificial gravity is not necessary for any mission profile in the foreseeable future.

But immensely useful.

[Nibb31]

But immensely useful.

Not really. But immensely complex, risky, and expensive.

[SargeRho]

And still immensely useful - that is, for anything that goes beyond the Earth-Moon system without some sort of "high speed" propulsion. 8 months of bone decay isn't something you want Astronauts to have to deal with going to Mars.

[Frozen_Heart]

The most well known way is a centrifuge. However at the small sizes that can be launched with current launchers they can only create very small gravity. A much larger centrifuge would be needed to create 1g (without the people being sick).

However they are heavy and complex so I don't expect to see one any time soon.

[Ikaneko]

Artificial gravity is not necessary for any mission profile in the foreseeable future.

Mars Direct calls for centrifugal force to be used in a sort of reverse yo-yo method.

Also, Mars missions will take 18 months. That's enough time for gravity-deprivation induced health problems begin to occur, including muscle wasting and loss of eyesight.

Pretty necessary.

[Nibb31]

They handle microgravity pretty well on the ISS these days. Orbital medicine has made a lot of progress since Polyakov's 14 month stay. 6 month stays on the ISS are routine and most of the effects these days can be compensated nowadays through medication and exercice, and there is more progress to be made.

On the other hand, we don't even know what level of artificial gravity would be beneficial, or even if it is detrimental compared to no gravity at all, because no long duration studies have ever been done. So adding artificial gravity as a requirement simply adds significant complexity and risk and pushes any Mars expeditions even further into the future until after we have done the prerequired science to validate the concept.

Which is why none of NASA's DRMs use rotating tethers or spinning habitats.

Even if it takes a few days for astronauts to readapt to partial gravity on Mars after a 6 month trip, it's not unsurmountable. Most mission profiles consider a stay on the surface of several weeks or months, so it's not like they will need to prepare for an EVA straight after landing like on Apollo 11.

Edited December 17, 2014 by Nibb31

[fairytalefox]

On the other hand, we don't even know what level of artificial gravity would be beneficial, or even if it is detrimental compared to no gravity at all

...and it would be very useful to know, wouldn't it? So we still need some form of artificial gravity, not immediately, though.

[Camacha]

Not really. But immensely complex, risky, and expensive.

If mankind wants to move forward in space flight in any serious shape of form, we need to tackle gravity in whatever way. Backyard missions are fun, but not what you would want in the long run.

They handle microgravity pretty well on the ISS these days. Orbital medicine has made a lot of progress since Polyakov's 14 month stay. 6 month stays on the ISS are routine and most of the effects these days can be compensated nowadays through medication and exercice, and there is more progress to be made.

Still, astronauts describe returning to Earth as a rather terrible experience, with days needed before you start to recover up to the level that you can do routine tasks. That is not what you need when you just landed on an alien planet.

Edited December 17, 2014 by Camacha

[Nibb31]

If mankind wants to move forward in space flight in any serious shape of form, we need to tackle gravity in whatever way. Backyard missions are fun, but not what you would want in the long run.

I guess there isn't much of an emergency because there's no indication that we're going anywhere other than our backyard in the next 30 years at least.

Edited December 17, 2014 by Nibb31