NASA’s Suni Williams and Butch Wilmore have returned to Earth from a weeklong mission at the International Space Station that turned into an unexpectedly extended stay.

Suni Williams and Butch Wilmore were originally supposed to spend only about a week in space before technical difficulties prompted their extended stay on the International Space Station.

Suni Williams and Butch Wilmore are gearing up to return toE Earth on Tuesday after an unexpected nine months aboard the ISS, and experts are sharing a number of health effects the pair might experience when they re-enter Earth's atmosphere.