7. Space Travel Might Be Making Astronauts Infertile
There are speculations that long-term space missions are making astronauts infertile. In one experiment, male rats suspended above the floor during a six-week-long experiment, mimicking the weightlessness of outer space, suffered shrunken testes and severely low sperm count, which made them as good as being infertile. Female rats suffered a similar or even worse fate when they were sent into space. Their ovaries ceased working after just 15 days. By the time they returned to Earth, the gene responsible for producing estrogen (the female hormone) had become redundant, while the cells that produced eggs were dying.
Space travel has also been linked to loss of libido. In one experiment, two male and five female mice sent into space refused to mate. However, some researchers insist that space travel has nothing to do with libido or infertility. Fish and frog eggs sent into space have fertilized, though the frog offspring never developed past tadpoles. Male astronauts have also impregnated their wives days after returning to Earth.
Female astronauts aren’t left out. They have also gotten pregnant soon after returning from space missions, although they have a higher rate of miscarriage. The effects of space travel on reproduction remain debatable, and from the look of things, we’re not finding out soon. NASA has turned down attempts to get the sperm count of its male astronauts returning from space for privacy reasons.