Testing the Human Body in Space for Extended Periods

iss046e015807 (January 21, 2016) --- NASA astronaut Scott Kelly (left) and Roscosmos Cosmonaut Mikhail Kornienko, participated in a jointly conducted one-year mission to better understand the effects of long-duration spaceflight on the human body. Scott Kelly was the first American astronaut to spend a year in space, during which he participated in the Twins Study to help scientists understand the impacts of spaceflight on human physiology and DNA through the study of identical twins.