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Space Time
A Year in Space Changed an Astronaut’s Genes
A new study of astronaut twins — one who spent a record time in orbit, the other who stayed on Earth — offers a clearer understanding of how space travel affects the human body
In 2015, NASA astronaut Scott Kelly journeyed to the International Space Station (ISS), where he spent a year orbiting Earth. It was the longest single stretch of time any American had spent in space and gave scientists an opportunity to study how the body changes while in orbit. Even better, Scott Kelly has a twin brother, Mark Kelly, also an astronaut, who served as a scientific control on Earth, allowing researchers to precisely compare the two.
This was the most complex and in-depth study of human spaceflight to date. The average time any astronaut spends on the ISS typically maxes out at six months. In the months leading up to Scott Kelly’s yearlong flight, NASA scientists collected urine, fecal, and blood samples from both brothers. Scott also collected a cache of samples during his year in space. Once he returned, the medical analysis continued.
After years of analysis, more data is emerging to illuminate how Scott’s year in space changed his body. A new paper published in the…
