6
$\begingroup$

It is well-known that the lack of gravity during spaceflight is a cause to many sorts of health issues.

It is thus expected that Martian gravity (significantly lower than Earth's) will have influence on humans. Especially if the perspective of long-term missions is considered.

Would it be worth considering to let humans sleep in some sort of centrifuges?

By this means, during sleep time, the human body could partly recover from the exposure to low gravity. The artificial gravity would be smoothly ramped up and down. It could be adjusted to various levels, so that the optimum could be identified experimentally.

$\endgroup$
  • $\begingroup$ Do you have any references to support the claim that "Martian gravity (significantly lower than Earth's) will have severe influence on humans"? There are questions about centrifuges that may be of interest here: space.stackexchange.com/questions/9575/… space.stackexchange.com/questions/22458/… $\endgroup$ – Organic Marble Apr 28 '18 at 19:37
  • 1
    $\begingroup$ @OrganicMarble It's not a claim but an expectation. And it's obvious: take any of the numerous experiences with stays in microgravity, e.g. copying Wikipedia: In addition to muscle loss, microgravity leads to increased bone resorption, decreased bone mineral density, and increased fracture risks. Bone resorption leads to increased urinary levels of calcium, which can subsequently lead to an increased risk of nephrolithiasis. All of these issues could play a role on Mars, with decreased intensity of course. $\endgroup$ – Everyday Astronaut Apr 28 '18 at 19:56
  • 1
    $\begingroup$ @OrganicMarble You were right, the word "severe" was a claim. I took it out. $\endgroup$ – Everyday Astronaut Apr 28 '18 at 20:00
  • 1
    $\begingroup$ @OrganicMarble That's the point with the decreased intensity. I guess there is much fewer experience with low gravity than there is with microgravity. $\endgroup$ – Everyday Astronaut Apr 28 '18 at 20:39
  • 1
    $\begingroup$ There are bed rest studies on Earth to simulate some effects of zero gravity. Exercises are needed within the centrifuges to get optimal health effects. There is no training of muscles and bones while sleeping. $\endgroup$ – Uwe Apr 29 '18 at 20:18
4
$\begingroup$

The short answer is: we don't know. We have usable data on physiological effects for only three gravity levels: zero, Earth g, and 1/6 Earth g, the latter for only three days or less at a time, so those data don't speak to long-term effects. We know of a host of effects from long-term zero g, and not just on bones. Among them: cardiovascular, vision, renal, even brain function. But we have no idea what the threshold g levels for these effects are. They might not be the same for all the effects. This argues for some research, based on actual data, before we send people to Mars for years-long stays on the surface. The only practical way to get long-term data on a range of g levels is to build habitats in space (probably LEO) that provide artificial gravity, whether they are the large Clarke/von Braun-style rotating stations, or just pairs of habitats rotating on a tether, or something else. The large station scenario is attractive because with a few design accommodations, you can experiment with a large range of g levels simultaneously, just by having habitats at different distances from the axis. Also, large size allows low rotation rates, which minimize rotation-induced vertigo.

$\endgroup$
  • $\begingroup$ We can add experience for gravity levels between Earth g and up to 5 g within a centrifuge. $\endgroup$ – Uwe Sep 8 at 18:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.