NASA and SpaceX on Friday launched a long-awaited crew to the International Space Station that opens the door to bringing home U.S. astronauts Butch Wilmore and Suni Williams, who have been stuck on the orbital lab for nine months.

The delayed mission must reach the space station before the two astronauts who've been "stuck" in space can return home.

NASA astronauts Butch Wilmore and Suni Williams arrived at the ISS aboard Boeing's Starliner spacecraft last June. The duo were flying the capsule's first crewed flight test, which was expected to stay in orbit for about 10 days before flying the pair back to Earth.