After 9 months in space, NASA astronauts Sunita William and Butch Wilmore are expected to come home sooner, as the space agency is looking for an ‘early' return. Stay tuned for more updates

Living in a microgravity environment leads to muscle atrophy and bone density loss. Since astronauts do not use their muscles in the same way as they do on Earth, their strength decreases over time. Despite regular exercise in space, they may experience weakness and need rehabilitation to regain full strength.