As humanity expands its activities in space, medical research into how our bodies cope with microgravity conditions has become the subject of numerous studies, including the effects of spaceflight on muscle mass and radiation exposure. Astronauts on future missions to the Moon or Mars will face increased risks to their vision and eye structure due to longer exposure to microgravity. The CIPHER study, consisting of 14 human studies, is examining the physical and psychological health of astronauts in space and applying these findings to supporting the health of crews on long-duration missions away from Earth.