Using Scott and Mark Kelly as test subjects, scientists from 12 different universities, NASA’s biomedical lab, and the National Space Biomedical Research Institute are carrying out ten separate investigations on the identical twins.
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Multiple research teams are working to suss out those changes, as part of the NASA Twins Study.
While the full results of the Twins Study probably won’t be released for another year or two, the first findings are now in.
That means the space agency had the ideal opportunity to figure out how extended periods in microgravity can affect the human body, and now that the first results from NASA’s Twin Study are in, it’s becoming clear that in some cases, the effects are the total opposite of what scientists were expecting.
Upon Scott’s return to Earth, researchers found that his telomeres – the protective caps on the end of DNA strands – were unexpectedly longer than Mark’s telomeres.
Spending a year in space affected former NASA astronaut Scott Kelly’s body in subtle but potentially significant ways, new research suggests.
Chemical modifications to Scott’s DNA increased while he was in space, but they returned to normal once he was back on Earth.
Telomere size wasn’t the only difference the researchers identified.
Telomeres shrink as a person ages, explains Rae Paoletta for Gizmodo, and scientists had previously believed that the stresses of spaceflight caused them to shorten at a faster speed. Researchers found that Scott’s telomeres grew longer than his brother’s, which was a surprise to the scientists.
Colorado State University radiation biologist Susan Bailey said one of the more interesting changes involved the length of Scott Kelly’s telomeres.
Levels for both men have since returned close to preflight levels. NASA speculates that the increase may have something to do with the low-calorie diet and strict exercise regimen Scott adhered to while on-board the ISS. “They’re turning humankind from an Earth-dwelling species into a space-exploring species”.
Those changes, though, also returned to normal once he returned to Earth, NASA said.
Changes were also spotted in the DNA of the twins. Current theories as to why this is happening range from the effects of microgravity to the simple act of eating freeze-dried food for 340 consecutive days. Additionally during his time in space, Scott experienced less DNA methylation – when certain types of molecules known as methyl groups are added to DNA molecules.
Scott Kelly looks at a tablet in his quarters on the Space Station. He retired from NASA in 2011 to help his wife, U.S. Rep. Gabrielle Giffords, who was recovering after an assassination attempt.
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“The preliminary results from the year-long ISS expedition and the associated Twin Study. have not identified any show-stoppers for longer human spaceflight missions”, NASA Human Research Program chief scientist John Charles said in a statement.
