Astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko are spending a year living aboard the International Space Station to help NASA learn more about the effects of long-term space travel on the human body.
Meanwhile, Scott’s brother and fellow astronaut, Mark Kelly, will be monitored on Earth, in a first-ever twins study of health effects comparing space flight to living on Earth. [Read more news about the one-year mission]
YEAR IN SPACE STUDY KEY QUESTIONS: