Williams and Wilmore both arrived at the ISS last June, aboard the first crewed test flight of Boeing's Starliner spacecraft. The astronauts were only slated for a 10-day mission, but issues with Starliner during docking led to multiple delays in their return, with NASA ultimately deciding to have Starliner make the journey back to Earth uncrewed.

"NASA and SpaceX are expeditiously working to safely return the agency’s SpaceX Crew-9 astronauts Suni Williams and Butch Wilmore as soon as practical, while also preparing for the launch of Crew-10 to complete a handover between expeditions," Cheryl Warner, NASA's news chief at the agency's headquarters, said in a statement to reporters.