NASA and SpaceX on Wednesday night scrubbed the Falcon 9 launch of a flight intended to retrieve from the International Space Station astronauts Suni Williams and Butch Wilmore, who have spent nine months in orbit.

The Crew-10 mission will send four astronauts to the space station to take over for Butch Wilmore and Suni Williams’ crew, finally allowing their return home.

The Crew-9 mission, consisting of NASA astronauts Nick Hague, Suni Williams and Butch Wilmore, along with Roscosmos cosmonaut Aleksandr Gorbunov, is set to return to Earth after a brief handover period with the newly arrived Crew-10 expedition crew, pending weather conditions at the splashdown sites off the coast of Florida.