Faking gravity in space with a spinning table


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Researchers at the University of Colorado in Boulder are experimenting with the use of a rotating table to give space-farers short doses of artificial gravity in order to mitigate the negative consequences of weightlessness.

In a series of recent studies, the pair and their colleagues set out to investigate whether queasiness is really the price of admission for artificial gravity. In other words, could astronauts train their bodies to tolerate the strain that comes from being spun around in circles like hamsters in a wheel?

The team began by recruiting a group of volunteers and tested them on the centrifuge across 10 sessions.

But unlike most earlier studies, the CU Boulder researchers took things slow. They first spun their subjects at just one rotation per minute, and only increased the speed once each recruit was no longer experiencing the cross-coupled illusion. “I present at a conference and everyone says, ‘she’s the one who spins people and makes them sick,'” Bretl said. “But we try to avoid instances of motion sickness because the whole point of our research is to make it tolerable.”

The personalized approach worked. By the end of 10th session, the study subjects were all spinning comfortably, without feeling any illusion, at an average speed of about 17 rotations per minute. That’s much faster than any previous research had been able to achieve.

The idea is that you could install this rotating table on a interplanetary ship, and have its occupants periodically spend time on it to get their daily dose of gravity. This way you would not have to build a giant spinning spaceship.

The research has potential. The one question that remains unanswered and is probably central to this concept is how little gravity is needed to avoid the problems of weightlessness. Right now, we do not know. It could be for example that 30 minutes at 1/10 g could do the job. Or maybe 1 g for 2 hours. If the former the engineering challenges become minor. If the latter the problems are more difficult.

I am aware of only one centrifuge experiment ever done in weightlessness, on a Russian space station. They rotated a plant at a very tiny percentage of g’s and found it might help plants prosper in space. The data point however is too small, with no followup. This is the kind of research that should be going on on ISS, and is not.

Hat tip Marcus A.

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12 comments

  • pzatchok

    Seriously?
    They are doing research on this?
    With more expensive equipment than you can find in a local carnival?

    Any spinning object will impart some spin to the space station its on. I hope they have a plan to counter that spin.
    And the only thing this type of contraption will do it keep the people healthier.
    Gravity has a thousand other just as important uses in space.
    For one you can’t even boil a good pot of water without gravity. how will anyone make a decent cup of tea?

    Just make the station bigger and spin the dang thing.

  • fred

    I am thoroughly upset that 100 billion was been spent on ISS and there has been no partial gravity research done.

  • Joe

    Nice news to hear! We can now shift the purpose of the ISS from a hub to launch lots of rockets to, to a true research station benefiting people living in space for long periods.

  • Wodun

    Anything that simulates bed rest won’t be effective. Mary Roach talked about this in one of her Space Show appearances and/or wrote about it in one of her books, Packing for Mars.

  • pzatchok

    The larger the centrifuge the less the effects of motion sickness.

    NASA keeps tying to do things inside a shoe box instead of just admitting that a larger station would work and take on the engineering problems of the larger station.

    Looking at the table they are testing on, you might as well just have someone sit in an office chair and spin them around. Heck in space they could just float in the station and someone could spin them around.
    Or how about a stripper pile in the middle of the room and use it like a tether ball set up. A harness attached so it doesn’t wind up like the tether ball does and around they go.
    Light weight and cheap. But again you need an area large enough and the space station doesn’t have one.

  • Edward

    fred wrote: “I am thoroughly upset that 100 billion was been spent on ISS and there has been no partial gravity research done.

    The module with the centrifuge at one end was cancelled due to budgetary considerations. To paraphrase Everett Dirksen: by saving a billion here, a billion there, pretty soon they were saving real money. Of course, they ended up with far less science for the bucks that they did spend, but then again: penny wise, pound stupid. What do you expect of politicians and bureaucrats?

    pzatchok wrote: “The larger the centrifuge the less the effects of motion sickness.

    Bigger might be better, “But they are imagining new ways to design revolving systems that might fit within a room of future space stations and even moon bases.” — From the article

    NASA keeps tying to do things inside a shoe box instead of just admitting that a larger station would work and take on the engineering problems of the larger station.

    That’s how we ended up with an expensive space station that does so much less than we had expected or paid for. Countering NASA’s very expensive and large manned Mars plan is why Robert Zubrin imagined a new and cheaper way to go to Mars, which he calls Mars Direct. That is why SpaceX is designing a single spacecraft to take people to Mars, so the company would not go broke building a multi-module craft that is larger than necessary.

    When it comes to propelling things in space, the shoe box is a nice size, which is why the Cubesat is such a hit with so many space explorers. Smaller might be better.

    If someone is going to spin you around for health purposes then you probably want the right spin speed, not an arbitrary speed that a coworker spins you to. Too fast and you get sick. Too slow and you miss out on the benefits that your precious time in the chair was supposed to give you.

    I hope they have a plan to counter that spin.

    Often, a moving mechanism on a spacecraft comes with its own counterweight that rotates or moves in the opposite direction in order to impart the least possible motion onto the rest of the spacecraft. There are some exceptions, such as the Canadarm.

  • pzatchok

    They have the subject in the apparatus wrong.

    His head is in close to zero G. His toes are in the highest G force area.

    He would get a better effect by placing his head to the outside and his feet to the inside.

    It takes more effort from your heart if you are hanging upside down than if you are just standing up.
    Plus the higher pressure in his head would help with the bad eye problem for astronauts. Their ocular fluid pressure goes down, changing the size and shape of their eye balls. Thus forcing them to use glasses for the first time. And their glasses need changing weekly.

  • pzatchok: I think you are incorrect here. The body is used to having the blood pool at the legs. That it doesn’t do so in weightlessness is one of the factors that causes problems in the spine, in the inner ear, in the cardio-vascular system.

    Having the subject lie with his feet on the outside pulls the blood downward, as is normal in gravity.

  • pzatchok

    But you have to increase the spin substantially to approach a high enough pressure. Gs.

    When walking the legs pump or assist the heart in returning blood and fluid back up to the body.
    If your not walking fluid just builds up in the legs. This happens with nursing home patients and the elderly all the time.
    That is why they sell compression socks to them.

    Spinal compression can be done just as easily by supporting the weight of the body with the shoulders.

    You have to get the heart and head into the high gravity zone.

  • Edward

    pzatchok wrote: “You have to get the heart and head into the high gravity zone.

    Actually, we don’t know this, because we have so little testing in the lower gravity zones. There is experience with long-term freefall (microgravity), laying horizontal in Earth gravity, a very little bit in lunar gravity, and some in higher gravity in centrifuges.

    In the absence of a spinning section of a space station or spacecraft, this spinning table is about the best we can hope for in our currently sized spacecraft.

    Wouldn’t it be interesting if SpaceX were to do some sort of testing in their somewhat larger Starship spacecraft? With trips to Mars in their future, they should have plenty of opportunity for long-term studies.

  • pzatchok

    It would be nice if NASA ordered the largest diameter habitat module Biggalo could build?

  • Edward

    pzatchok wrote: “It would be nice if NASA ordered the largest diameter habitat module Biggalo could build?

    It would be nice if anyone ordered one. However, it seems that we will have to wait until commercial manned spacecraft are flying before Bigelow Aerospace puts one up. Yes, it would be nice if they were to put a large centrifuge in one of them. I can imagine it would be used for a large number of experiments.

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