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Why have I not seen any spin gravity testing in space? Or, more accurately, artificial gravity created through centrifugal/centripetal force. I haven't heard of any tests in standalone spacecraft or attached to the ISS, or any station.

Many far future sci fis have massive spinning cylinder ships and stations, multiple km long. But what about the precursors to this... or simply those more realistic in terms of cost and materials needed, such as:

  • Cheapest: wire tethered capsules, such as Mars Direct ideas by R Zubrin: enter image description here
  • 2nd Cheapest?: spinning stiff trusses with capsules at each end: enter image description here
  • Quite costly: spinning rings: enter image description here

I've seen centrifuge tests done on the earth surface (which overpower Earth g but cannot eliminate it), but have seen none attempted in space so far. Space allows testing of Lunar and Mars levels of g. The tethered capsule could even be a very small setup for lab rats. This seems hugely important for longer duration space travel, considering all of the bad effects of microgravity. A tether could be sent up and attached to spin existing small containers or entire ISS modules. Or SpaceX Dragon capsule with its spent booster as counterweight.

The math and mechanics are not a problem. Getting materials strong enough at reasonable launch weights isn't a problem. Controlling the spin through motors and/or thrusters should not be a problem. Tests could start at days long, then weeks, then months, and so on.

Even small, relatively cheap steps haven't been taken to space, such as 1-2 tiny capsules of lab rats spun on say 30-50m of light cable, near the ISS (not even attached to it, to avoid any disruptions such as vibration). Or anywhere in LEO, with plenty of sensors and cameras inside to monitor things.

It seems very feasible... so I ask, why have I not seen spin gravity testing done in space? (I looked, I swear :D)

Koon W
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    Highly related, possible duplicate https://space.stackexchange.com/q/1308/6944 – Organic Marble Mar 17 '21 at 02:56
  • That does not address the low cost methods of wire cables or trusses – Koon W Mar 17 '21 at 03:10
  • although i appreciate the link because there is great info on there! – Koon W Mar 17 '21 at 03:12
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    Interesting question! I've wondered the same thing. Why zero progress on this front? Humans aren't built for long stretches in microgravity and the only practical way to reproduce gravity on a spaceship seems to be centripetal forces. So why no tests? Why no progress? I find hard to believe we'll ever truly be a spacefaring species without some means to reliably reproduce gravity in space. It just won't happen, full stop. –  Mar 17 '21 at 03:16
  • And I'm not talking about the odd well-trained and risk-tolerant astronaut spending a few months on ISS. For people to travel through space in large numbers, as Elon Musk envisions, we'll need some means to reproduce gravity. I'm honestly baffled why artificial gravity exists only in science fiction. Disappointed, honestly. The least you'd expect in 2021 is many practical tests done on this front. Yet there are seem to be none. Excellent question. –  Mar 17 '21 at 03:19
  • It's obviously not a flaw in the concept, but rather the opposite. I think that its such a straight forward idea that it doesn't really need to be tested and it'd probably just be a waste of time – R. Hall Mar 17 '21 at 04:20
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    I've heard it claimed that gravity tethers tend to build up vibrations. Also, the minimal viable spacecraft to experiment with this is kind of big. – ikrase Mar 17 '21 at 05:54
  • Since 1) Why are there no spacecraft rotating for artificial gravity? exist and is similar to your current wording and 2) Blue Origin is going to do spin-based artificial gravity quite soon, why not adjust yoru question to as "How soon will spin-based artificial gravity be demonstrated in space?" which is very different than the other OLD question and will have one or more NEW and interesting answers! – uhoh Mar 17 '21 at 08:34
  • @GdD our comments crossed, hopefully the question doesn't get shut down and answers blocked before adjustments can be made. – uhoh Mar 17 '21 at 08:36
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    You're assuming that's the author's intent @uhoh. It may be that the question is answered by the other post. – GdD Mar 17 '21 at 08:38
  • @GdD no I've assumed nothing at all. I've simply recommending that the question be modified. I'm sure the OP"s intent is to ask the question as asked, but since it's not hard to adjust this into a new question I've presented an option. In my experience if the new question is only 20% different than a closed question and has the same images, enough people will try to close it also without taking the time to see the difference. So in my experience modification is more successful than reposting, and getting it done before the question is closed saves days. – uhoh Mar 17 '21 at 09:59
  • @GdD Making a new user's first (and well written) question a more rewarding and less troublesome experiences is good for the site because it encourages folks to stick with SE as they get used to its peculiar nature. People don't join Stack Exchange (usually) because they have just one question, they come to participate. – uhoh Mar 17 '21 at 10:01
  • @GdD however, unfortunately all that goes out the window when someone posts another answer to the duplicate question here instead of there.:-) Now the question can't be modified. – uhoh Mar 17 '21 at 13:36

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Even small, relatively cheap steps haven't been taken to space

Leaving aside the idea that there's such a thing as "cheap" in space: Sept. 14, 1966 - Gemini XI Artificial Gravity Experiment

Gemini XI separated from the Agena with their spacecraft pointed nose-down toward the Earth. Conrad and Gordon maneuvered their craft to keep the tether taut between both. By firing their side thrusters to slowly rotate the combined spacecraft, they were able to use centrifugal force to generate about 0.00015 g. "There is an artificial gravity field," Gordon said. "It makes the camera move back very rapidly." The tether was released following two orbits of the artificial gravity experiment, allowing Gemini and Agena to go their separate ways.

Gemini XI artificial gravity experiment

Starfish Prime
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