Dr. Francine Garrett-Bakelman

After extensive data gathering and analysis—plus a worldwide media Frenzy—NASA’s famed Twins Study has begun to yield results.

Long-term spaceflight causes more changes to gene expression than shorter trips, especially to the immune system and DNA repair systems, according to research by Weill Cornell Medicine and NASA investigators as part of NASA’s Twins Study, which followed the only set of identical twin astronauts for more than two years.