NASA astronauts are returning to Earth after nine months in space. Experts have said a prolonged period in space can come with changes to human physiology and psychology.

NASA astronauts Butch Wilmore and Suni Williams departed the International Space Station in a SpaceX capsule for a long-awaited trip back to Earth, nine months after their faulty Boeing Starliner craft upended what was to be a roughly week-long test mission.

Barry Wilmore and Sunita Williams have been at the International Space Station since June after technical issues with their spacecraft.