Scientists fear that being in space for a long time may make both male and female astronauts infertile, as studies suggest.
Experiments in animals show that space radiation causes damage to the sperm reproduction of men and to ovaries of women.
In a study conducted by researchers at University of Kansas’ Department of Molecular Integrative Physiology, they found out that when rats are hoisted up on their hind legs, there are changes to their cells that affect their sperm production, making them infertile. The rats were hoisted to recreate the conditions in space.
According to the International Business Times UK, lead researcher Dr. Joseph Tash said that there were no changes in the rats’ behavior.
“The changes in the histology suggest that they could no longer produce sperm that was functional. The animals still had a strong mating urge. So a male astronaut could come back without any change in behavior but they may be shooting blanks and maybe they are unaware there is a problem.”
Previous studies conducted in Russia showed that female and male rats which were sent into space in 1979 did not mate. Another study showed that when male rats were placed in zero gravity, they no longer produce sperm, Telegraph UK reported.
Dr. Tash said that they are not sure if the same conditions apply to humans, but he said that exposure to radiation could affect the ovaries, eyes, and testes. The U.S. space agency is now studying the mating of mice who are on board the ISS (International Space Station) to see how grave the problem is.
NASA is also concerned about the issue, and is already offering sperm and egg freezing for astronauts, especially since they are preparing for the Mars One mission, which is set to send the first crew on Mars in 2025.
Dr. Tash also said that the testes are the part of the body that is the most sensitive to radiation, with the eyes being the next most sensitive. Plenty of astronauts who have spent about six to eight weeks in space came back with eye problems.
Furthermore, experiments show that space affects sperm in such a way that they swim faster in space. However, the influence of having faster sperm is still unknown.
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