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.

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

NASA astronauts Butch Wilmore and Suni Williams are set to splash down on Earth on Tuesday evening after spending more than nine months in space.