NASA Twins Study: Body Changes Over Time in Space NASA Twins Study: Body Changes Over Time in Space

Brothers Scott and Mark Kelly were 51 in March 2015, when Scott began his fourth and longest space mission — commanding the International Space Station for 340 days, which set an American record.WebMD Health News

Source: Medscape Medical News Headlines - April 15, 2019 Category: Consumer Health News Tags: Pathology & Lab Medicine News Source Type: news