5 ms·

Given that lack of gravity seems to be a major risk factor for well-being I'm surprised a static structure like the ISS doesn't yet have a rotating centrifuge-l

Given that lack of gravity seems to be a major risk factor for well-being I'm surprised a static structure like the ISS doesn't yet have a rotating centrifuge-like structure ala 2001: A Space Oddysey to at least ward off the effects during sleep and downtime

thatswrong0 9y ago
Well they do have those tied-down-with-a-spring treadmills, but that only covers you for the duration of your workout. I don’t know anything about constructing things for use in a space station, but I can’t imagine creating such a rotating structure would be easy, cheap, or safe.. a problem with a structure rotating quickly in space could quickly cause major safety issues for the ISS I’d imagine.
- baddox 9y ago
  Resistance training is certainly still possible, but you still lose the normal ambient resistance you get on earth just from walking around and holding your limbs in place against gravity. The difference between low-gravity and someone on Earth who doesn’t exercise much is probably much larger than the difference between a non-exercising Earthling and an Earthling who exercises. Besides, that doesn’t really work for the other physiological effects of low gravity, like the heart and circulation issues mentioned in the article.
  - thatswrong0 9y ago
    Great point about the treadmill. I guess my point is that I just can’t imagine that all the brilliant people involved with the ISS _didn’t_ think of a rotating structure.. but even just getting a sizable non-rotating structure cost 150B. I wonder what kind of health issues we’d see even with a rotating structure tho. Would living on such a structure really help prevent most of these issues?
    - baddox 9y ago
      Other comments in this thread have discussed it. Sounds like NASA is well aware of rotating structures, but large ones are way too expensive and small ones cause other issues due to the fast rotation required.
chrishacken 9y ago
There actually was a proposal for one. https://en.wikipedia.org/wiki/Nautilus-X https://en.wikipedia.org/wiki/Nautilus-X There's also this issue: "Another problem is that we do know of adverse effects that arise at high rotational rates of speed. The Coriolis Effect has to do with rotating reference frames and it can seriously screw with the inner ear. The only way to maintain a strong centrifugal gravity while keeping rotational speed low is to lengthen the system as a whole — but the ISS isn’t nearly big enough." Source: https://www.geek.com/news/geek-answers-why-doesnt-the-iss-have-artificial-gravity-1563351/ https://www.geek.com/news/geek-answers-why-doesnt-the-iss-ha...
- digi_owl 9y ago
  So in effect if your feet are moving faster than your head by just enough for the inner ear to pick it up, you are likely to look at outcomes similar to motion sickness...
- whatshisface 9y ago
  Zero-G also makes people sick, but astronauts can get used to it. If you put someone in a small spinning station for six months, would they also get used to the motion sickness? What if you found someone suffering from (and that had learned to live with) permanent vertigo?
  - foota 9y ago
    Shouldn't motion sickness only happen when you have a reference frame? i.e., if you're on the space station you shouldn't be able to tell when it's spinning?
    - travisjungroth 9y ago
      A rotating object isn't exactly the same as gravity. There's a rotational effect that exists, so you can tell the difference between being on the ground and in a centrifuge.
    - aetherson 9y ago
sitharus 9y ago
One was planned, but it was cancelled due to budget overruns: https://en.m.wikipedia.org/wiki/Centrifuge_Accommodations_Module https://en.m.wikipedia.org/wiki/Centrifuge_Accommodations_Mo...
- Retric 9y ago
  Humans would not have fit. The goal was to "Expose a variety of biological specimens that are less than 24.5 in (0.62 m) tall"
rocqua 9y ago
As others have stated, if you don't take a very large diameter, the Coriolis effect starts to be really disorienting. That can be counteracted somewhat by reducing the speed of rotation, but that comes at the cost of lower effective gravity.
jacquesm 9y ago
The ISS is simply too small for that. It would have to spin at a ridiculous rate in order to get to a level of gravity where the effects are no longer felt. And in this particular case that is actually a blessing because even if the space station would be able to do this the spaceship used for any interplanetary traveling would not and so no useful data for such a trip would be collected.
- yorwba 9y ago
  Since the centrifugal force for mass m, angular velocity w and radius r is mw²r, you only need w = sqrt(g/r) to reproduce Earth-like levels of acceleration. At r = 10 m, that's already less than 1 rad/s or 1/6 cycle/s. That doesn't seem ridiculously fast. And why wouldn't an interplanetary spaceship be able to spin fast enough? You could just build it as a space station with thrusters.
  - dredmorbius 9y ago
    The O'Neil space station designs were premised on 1 RPM. Though a 3 RPM environment might be tolerable continuously, switching between rotating and non-rotating environments suggested a lower rate. See: http://www.nss.org/settlement/ColoniesInSpace/colonies_chap08.html http://www.nss.org/settlement/ColoniesInSpace/colonies_chap0...
  - CapitalistCartr 9y ago
    To make it Earth-like, and not make people nauseous, it has to have a diameter around 200 meters. Less than one G is practical, though. As little as 0.25 G might forestall the medical complications.
  - Johnny555 9y ago
    Sounds like you've just described the "Graviton", a popular amusement park ride. While a 30 second ride may be fun, I couldn't imagine living on it for months at a time. (granted, it simulates > 1G) https://en.wikipedia.org/wiki/Gravitron https://en.wikipedia.org/wiki/Gravitron
  - z3t4 9y ago
boznz 9y ago
Lack of gravity also means there will never be a permanent presence in space. Making a big station and spinning it is the only way anyone is going to survive in space for more than a few years. I guess if the costs of sending something into space comes down this will become an option, then they just have to solve radiation shielding and everyone will be happy. Of course no tests have been actually done so both are assumptions..
ge96 9y ago
I love that movie. The bone-space montage is so good.
emiliobumachar 9y ago
The ISS is, primarily, our single microgravity laboratory. Giving it gravity would make it unfit for that role. (NASA could duplicate the radiation and confinement here on Earth relatively easily, if not for the ethical issues. These seem to not matter as much when compensated with the privilege of going to space. But making gravity on space just to hack an ethically acceptable experiment would start to get ridiculous.)
- justin66 9y ago
  > The ISS is, primarily, our single microgravity laboratory. Giving it gravity would make it unfit for that role. Centripetal force is not truly gravity. This is useful because a station simulating gravity by spinning can still have areas that are isolated from this force (the center).

thatswrong0 9y ago

Well they do have those tied-down-with-a-spring treadmills, but that only covers you for the duration of your workout. I don’t know anything about constructing things for use in a space station, but I can’t imagine creating such a rotating structure would be easy, cheap, or safe.. a problem with a structure rotating quickly in space could quickly cause major safety issues for the ISS I’d imagine.

baddox 9y ago
Resistance training is certainly still possible, but you still lose the normal ambient resistance you get on earth just from walking around and holding your limbs in place against gravity. The difference between low-gravity and someone on Earth who doesn’t exercise much is probably much larger than the difference between a non-exercising Earthling and an Earthling who exercises. Besides, that doesn’t really work for the other physiological effects of low gravity, like the heart and circulation issues mentioned in the article.
- thatswrong0 9y ago
  Great point about the treadmill. I guess my point is that I just can’t imagine that all the brilliant people involved with the ISS _didn’t_ think of a rotating structure.. but even just getting a sizable non-rotating structure cost 150B. I wonder what kind of health issues we’d see even with a rotating structure tho. Would living on such a structure really help prevent most of these issues?
  - baddox 9y ago
    Other comments in this thread have discussed it. Sounds like NASA is well aware of rotating structures, but large ones are way too expensive and small ones cause other issues due to the fast rotation required.

chrishacken 9y ago

There actually was a proposal for one. https://en.wikipedia.org/wiki/Nautilus-X https://en.wikipedia.org/wiki/Nautilus-X There's also this issue: "Another problem is that we do know of adverse effects that arise at high rotational rates of speed. The Coriolis Effect has to do with rotating reference frames and it can seriously screw with the inner ear. The only way to maintain a strong centrifugal gravity while keeping rotational speed low is to lengthen the system as a whole — but the ISS isn’t nearly big enough." Source: https://www.geek.com/news/geek-answers-why-doesnt-the-iss-have-artificial-gravity-1563351/ https://www.geek.com/news/geek-answers-why-doesnt-the-iss-ha...

digi_owl 9y ago
So in effect if your feet are moving faster than your head by just enough for the inner ear to pick it up, you are likely to look at outcomes similar to motion sickness...
whatshisface 9y ago
Zero-G also makes people sick, but astronauts can get used to it. If you put someone in a small spinning station for six months, would they also get used to the motion sickness? What if you found someone suffering from (and that had learned to live with) permanent vertigo?
- foota 9y ago
  Shouldn't motion sickness only happen when you have a reference frame? i.e., if you're on the space station you shouldn't be able to tell when it's spinning?
  - travisjungroth 9y ago
    A rotating object isn't exactly the same as gravity. There's a rotational effect that exists, so you can tell the difference between being on the ground and in a centrifuge.
  - aetherson 9y ago

sitharus 9y ago

One was planned, but it was cancelled due to budget overruns: https://en.m.wikipedia.org/wiki/Centrifuge_Accommodations_Module https://en.m.wikipedia.org/wiki/Centrifuge_Accommodations_Mo...

Retric 9y ago
Humans would not have fit. The goal was to "Expose a variety of biological specimens that are less than 24.5 in (0.62 m) tall"

rocqua 9y ago

As others have stated, if you don't take a very large diameter, the Coriolis effect starts to be really disorienting. That can be counteracted somewhat by reducing the speed of rotation, but that comes at the cost of lower effective gravity.

jacquesm 9y ago

The ISS is simply too small for that. It would have to spin at a ridiculous rate in order to get to a level of gravity where the effects are no longer felt. And in this particular case that is actually a blessing because even if the space station would be able to do this the spaceship used for any interplanetary traveling would not and so no useful data for such a trip would be collected.

yorwba 9y ago
Since the centrifugal force for mass m, angular velocity w and radius r is mw²r, you only need w = sqrt(g/r) to reproduce Earth-like levels of acceleration. At r = 10 m, that's already less than 1 rad/s or 1/6 cycle/s. That doesn't seem ridiculously fast. And why wouldn't an interplanetary spaceship be able to spin fast enough? You could just build it as a space station with thrusters.
- dredmorbius 9y ago
  The O'Neil space station designs were premised on 1 RPM. Though a 3 RPM environment might be tolerable continuously, switching between rotating and non-rotating environments suggested a lower rate. See: http://www.nss.org/settlement/ColoniesInSpace/colonies_chap08.html http://www.nss.org/settlement/ColoniesInSpace/colonies_chap0...
- CapitalistCartr 9y ago
  To make it Earth-like, and not make people nauseous, it has to have a diameter around 200 meters. Less than one G is practical, though. As little as 0.25 G might forestall the medical complications.
- Johnny555 9y ago
  Sounds like you've just described the "Graviton", a popular amusement park ride. While a 30 second ride may be fun, I couldn't imagine living on it for months at a time. (granted, it simulates > 1G) https://en.wikipedia.org/wiki/Gravitron https://en.wikipedia.org/wiki/Gravitron
- z3t4 9y ago

boznz 9y ago

Lack of gravity also means there will never be a permanent presence in space. Making a big station and spinning it is the only way anyone is going to survive in space for more than a few years. I guess if the costs of sending something into space comes down this will become an option, then they just have to solve radiation shielding and everyone will be happy. Of course no tests have been actually done so both are assumptions..

ge96 9y ago

I love that movie. The bone-space montage is so good.

emiliobumachar 9y ago

The ISS is, primarily, our single microgravity laboratory. Giving it gravity would make it unfit for that role. (NASA could duplicate the radiation and confinement here on Earth relatively easily, if not for the ethical issues. These seem to not matter as much when compensated with the privilege of going to space. But making gravity on space just to hack an ethically acceptable experiment would start to get ridiculous.)

justin66 9y ago
> The ISS is, primarily, our single microgravity laboratory. Giving it gravity would make it unfit for that role. Centripetal force is not truly gravity. This is useful because a station simulating gravity by spinning can still have areas that are isolated from this force (the center).