The two NASA astronauts stuck in space after Boeing’s Starliner experienced issues earlier this year have been hit with a new delay.

Astronauts Suni Williams and Butch Wilmore were part of Boeing’s long-delayed mission in early June. The initial launch was delayed several times due to thruster failures and helium leaks.

Williams and Wilmore’s trip was initially meant to last about eight to 10 days, but the Starliner prompted NASA to be concerned and leave them at the International Space Station (ISS). The capsule returned to Earth in September.

A new SpaceX craft was meant to be used for the return mission of the two astronauts, but NASA pushed back the mission from February to at least late March.

“NASA’s SpaceX Crew-10 now is targeting no earlier than late March 2025 to launch four crew members to the International Space Station,” NASA said in a release.

With another delay in getting them home, Wilmore and Williams will have been on the ISS for nine months.

NASA said the timeline change allows its teams to “complete processing” on a new spacecraft for the mission. It’s set to arrive at the company’s Florida facility in early January.

“Fabrication, assembly, testing, and final integration of a new spacecraft is a painstaking endeavor that requires great attention to detail,” Steve Stich, the manager of NASA’s Commercial Crew Program, said in a statement.