The study looks at what happened to Kelly before, during and after he spent one year aboard the International Space Station through an extensive comparison with his identical twin, Mark, who remained on Earth.
NASA has learned that the formerly identical twins are no longer genetically the same.
The transformation of 7% of Scott’s DNA suggests longer-term changes in genes related to at least five biological pathways and functions.
The newest preliminary results from this unique study of Scott, now retired from NASA, were released at the 2018 Investigator’s Workshop for NASA’s Human Research Program in January. Last year, NASA published its first round of preliminary results at the 2017 Investigator’s Workshop. Overall, the 2018 findings corroborated those from 2017, with some additions.