Mice in space and kept in artificial gravity experience no harm to reproduction

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The uncertainty of science: Male mice who spent thirty-five days on ISS but within a centrifuge that created 1 g of artificial gravity apparently experienced no damage to their ability to reproduce.

This project team developed a habitat cage unit (HCU) capable of being installed in the Centrifuge-equipped Biological Experiment Facility (CBEF) on the ISS. The mice were placed under artificial gravity or microgravity (by centrifugation). After their return to Earth, they were compared with a “ground control” raised on the ground for the same 35-day period. (Fig.1)

The joint team found that: [1] The sperm production ability and the sperm fertilizing ability of the mice returned to Earth were normal, compared to the ground control and, [2] offspring of the mice sent to outer space was healthy and there were no effects on their reproduction ability from their parents’ stay in outer space.

While this study suggests that some form of artificial gravity can possible mitigate some of the risks to reproduction in space, there are so many unknowns that it at this point it leaves more questions than it answers.

  • Would an artificial gravity less than 1 g accomplish the same thing?
  • Would no gravity cause damage? According to the study, this is not yet known.
  • What about insemination? Would it proceed with no problems in space?
  • What about female reproduction? Will artificial gravity mitigate issues for them?

I could go on. I almost wish they had done this experiment first in zero gravity, to see its effects, before proceeding to an artificial gravity environment.

Nonetheless, these results do suggest that reproduction in space will be possible, as long as an artificial gravity of some kind is provided.


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  • Joe

    This is a good experiment but like you mentioned, it isn’t complete. The real answer we need to know is, “What is the minimal amount of gravity needed to keep humans healthy?” This test was performed at 1g. Let’s do it again at 0.5g, 0.25g, etc.

  • Wodun

    It just says their trip to space didn’t harm their sperm. It doesn’t say anything about copulation in space. Presumably, we already know the effects of microgravity of sperm in other travelers that have returned from space. What is the difference, if any, between the two?

    I’m curious as to the disposition of the mice in the centrifuge. Were they strapped in or were they free to roam around? This is important because other studies have shown that artificial gravity that simulates bed rest is just as bad for the body as bed rest. So, also interested to know if they looked at things like bone density and cardiovascular health of the mice.

  • Wodun: My post included a link directly to the paper, which would answer your question.

  • David K

    Test moon gravity next! If it’s ok there, Mars should be fine.

  • Joe from Houston

    No one cares about that experiment? The obvious experiment they can do is measure the bone mass and compare it with the base case. Are they the same, then ok, we solved the bone mass issue stopping us dead in our tracks to long term space exploration. BOOYAH!!

  • Michael G. Gallagher

    When I read this I immediately thought about Confinement Asteroid from Larry Niven’s Known Space series. Confinement was a hollowed out asteroid rotated to 1G. It’s purpose was to liberate the Belters, the settlers in the Asteroid Belt, from one of their last physical ties to Earth by providing a safe place for their women to give birth.

  • pzatchok

    We need bigger facilities in space. huge in fact.

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