Boeing Starliner astronauts who were supposed to be in space for nine days returning to Earth after nine months on ISS

The two U.S. astronauts who had been at the International Space Station for nine months after their faulty Boeing Starliner capsule returned without them are finally heading home.

NASA astronauts Butch Wilmore and Suni Williams left Earth in June on a test flight that was originally intended to last about nine days.

But their stay was extended after thrusters on Boeing’s Starliner capsule “Calypso” failed during docking, raising concerns about the ship’s ability to carry them home. The agency ultimately sent the capsule back empty after it was docked for about three months at the space station, saying it wanted to “further understand the root causes” of the spacecraft’s issues.

NASA also announced that Wilmore and Williams, who are both veteran astronauts and retired Navy test pilots, would return on a SpaceX Dragon spacecraft instead. The agency adjusted its rotation of astronauts as a result, removing two people from SpaceX’s Crew-9 mission — which is returning to Earth this week — to make room for Wilmore and Williams.

That capsule carrying the two people on Crew-9 arrived at the ISS back in September. Crews rotate on the ISS, which means that each group of astronauts works until the next arrives at the space station, when a ceremonial “handover” occurs.

NASA had originally planned for SpaceX’s Crew-10 mission — which needed to arrive before the Crew-9 members could come back down — to launch in February, but it was delayed by about a month.

The rocket carrying the four new crew members launched on Friday evening, and its capsule docked at the space station about 29 hours later.

Wilmore, Williams, NASA astronaut Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov are set to splash down Tuesday evening, about 19 hours after closing the hatch on the SpaceX capsule, according to NASA’s estimated schedule.

The Starliner crew flight test was supposed to check a final box for Boeing and deliver a key asset for NASA. The agency was hoping to fulfill its dream of having two competing companies — Boeing and Elon Musk‘s SpaceX — flying alternating missions to the ISS.

Instead, it’s unclear what Boeing’s future crewed space plans are. The company has lost more than $2 billion on its Starliner spacecraft.

Wilmore and Williams’ journey became entangled in politics once President Donald Trump took office. Trump and Musk, who has become a close advisor to the president, urged a quicker Crew-10 launch and said without evidence that the two astronauts were “stranded” on the space station and that the Biden administration had kept them up there for political reasons. NASA had delayed the Crew-10 launch in December to allow more time to process a new Dragon capsule, but decided to use a reusable capsule to cut down on wait time.

NASA’s plans for returning the two astronauts have remained consistent since the agency announced them in August.

During their extended stay, Wilmore and Williams became part of a normal rotation, conducting scientific experiments and routine maintenance as any other astronaut on rotation at the ISS would. Williams also conducted a spacewalk.

Williams has said repeatedly that the pair doesn’t feel “abandoned” at the ISS, but that she was looking forward to returning home to see her family and her two dogs.

“It’s been a roller coaster for them, probably a little bit more so than for us,” she told reporters earlier this month.