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 are set to arrive home on SpaceX after spending 9 months on the ISS after Boeing’s Starliner was sent back empty.

Astronauts Butch Wilmore and Suni Williams were scheduled to return home last year before issues with Boeing’s spacecraft extended their stay.