Tag Archives: centrifuge

Faking gravity in space with a spinning table

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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A centrifuge costing 20 cents based on a toy

Scientists at Stanford have developed a centrifuge costing 20 cents to make, based on a child’s toy, that can be used in the field to separate blood samples.

According to Stanford, Prakash and post-doctoral fellow Saad Bhamla came up with the “paperfuge” while looking at toys like tops and yo-yos for inspiration. Noticing how the disc of a whirligig spins when the cords on either side are pulled, they decided to make a slow motion video of one, only to discover that it rotated at 10,000 to 15,000 RPM.

The pair started developing prototypes using a blood capillary tube mounted on a paper disc, but they went beyond simple tinkering as they recruited three undergraduate engineering students from MIT and Stanford to create mathematical models of how the whirligig could change a pulling motion into a rotary motion. Looking at variables like disc size, string elasticity, and pulling force, they combined this with equations from the physics of supercoiling DNA to gain a better understanding of the whirligig’s mechanism.

The result was a centrifuge made of 20 cents of paper, twine, and plastic that could spin at 125,000 RPM, generate 3,000 G’s, and process samples in 1.5 minutes.

I have embedded a video explaining the paperfuge below the fold. I wonder if a variation of this on ISS could do low gravity experiments.
» Read more

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Russians to put first centrifuge on ISS

Russia today announced that they are developing and plan to launch the first small centrifuge ever to fly in space.

The centrifuge would be installed on an inflatable module that Russia’s Institute of Biomedical Problems, which specializes in studying the medical problems of space travel, is building, and would be used to study the effects of artificial gravity in weightlessness.

Unfortunately, the announcement doesn’t tell us much more than this. Based on previous such announcements from Russia, I would not be surprised if this project never flies.

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ISS to finally get an experimental centrifuge

At last! The ISS is to finally going to get an experimental centrifuge.

I have studied at length all the research done on all the space station ever launched, from Skylab, all the Russian Salyut stations, Mir, and now ISS, and from I could tell, only once was a centrifuge experiment put in space, by the Russians. Though the centrifuge was small and the results inconclusive, they suggested that even the addition of a truly miniscule amount of force could significantly mitigate the effects of weightlessness on plants and materials.

To finally get an experimental centrifuge on ISS is wonderful news. In order to build an interplanetary spaceship as cheaply and as efficiently as possible using centrifugal force to create artificial gravity we need to know the minimum amount of centrifugal force we need. Less energy will probably require less complex engineering, which should also require less launch weight to orbit, lowering the cost in all ways.

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