For 340 days, astronaut Scott Kelly lived in the International Space Station, while his identical twin brother Mark Kelly, a retired astronaut, lived a regular life on Earth. Both collected physiological and cognitive data about themselves, hoping to find out what space would do to a human’s body.
The Twins Study, conducted in collaboration between NASA and multiple institutions including Weill Cornell Medicine, analyzed the differences between the twin brothers to explore how human bodies change after long-term spaceflight.
“We basically look at how DNA and RNA are regulated,” Prof. Christopher Mason, physiology and biophysics, one of the study’s principal investigators, told The Sun. “The really big focus was on what happens to gene expression levels and how genes are regulated when they get turned on and turned off during space flight.”
Mason has long been interested in studying the genetics of astronauts. He first reached out to NASA in 2010, which, at the time, had no genome data available to conduct this kind of experiments. When the opportunity finally arose in 2014, NASA picked the Weill Cornell team as one of ten teams of researchers participating in the twins study.
According to The New York Times, the most significant findings from the 90-page paper published on Friday are genetic mutations and worsened cognitive performance. After Kelly’s return, some of his cells mutated, making him more vulnerable to developing cancer. Six months after he came back to Earth, Scott also responded more slowly and made more mistakes on cognition tests compared to his brother.
The study helps researchers understand how human bodies respond to long periods of spaceflight, which may be useful when developing ways to protect astronauts from health damage caused by prolonged time in space. They may also help patients on Earth who have been exposed to substantial radiation, according to a press release from the University.
“The experiments gave the most comprehensive genetic and molecular map of any astronaut,” Mason said.
Despite the breakthrough, there is more work to be done, Mason said. He and collaborators plan to look at many more datasets in greater detail, and publish the findings in subsequent companion papers.
“Gene expression changed dramatically… We don’t know yet if these changes are good or bad. This could just be how the body responds, but the genes are perturbed, so we want to see why and track them to see for how long,” Mason said in the same press release.