“Exposure to short duration gravity load changes including microgravity, as sustained in a parabolic flight statistically significantly decreases the sperm motility and vitality of human fresh sperm samples,” the team found, adding that this may have huge importance for any prolonged human settlement missions in space.
“In the future, should humans remain in space for long periods of time with exposure to different microgravity and hypergravity peaks, which could range from months to a number of years, reproduction may pose a problem to be tackled.”
The mechanism by which sperm motility was decreased remains unknown, with further study needed.
Especially considering the samples were exposed to supergravity as the plane came out of its dive. I feel like that would mostly invalidate whatever they were hoping to find.
Also, why do they dismiss asking ISS staff to participate in studies? Bodily autonomy doesn’t mean you can’t ask someone to conduct … uh… research with you. It just means you have to respect it they say no. Astronauts seem like the types who wouldn’t mind putting in a little extra effort for… science.
Too many other introduced variables? Microgravity has a lot of other systemic effects on the astronauts that might affect sperm motility, even before effects to the sperm themselves. Or just individual variation/genetics on the part of the astronauts themselves.
They wouldn’t be able to get a sperm sample that wasn’t affected by microgravity from the astronauts to begin with.