Butch Wilmore and Suni Williams are heading home after about nine months at the International Space Station. The two veteran NASA astronauts were only supposed to be in space for a little more than a week.

That’s how long Boeing Starliner’s mission — its first flight test with crew aboard — was supposed to last. But this mission has been singular in almost every way, and astronauts Butch Wilmore and Suni Williams have instead spent the past nine and a half months aboard the International Space Station.