The two astronauts took off in June on the Boeing Starliner spacecraft for its first crewed test flight.
ADVERTISEMENTTwo NASA astronauts on what was supposed to be an eight-day mission to the International Space Station (ISS) might stay up there until February 2025.
Astronauts Suni Williams and Butch Wilmore originally took off for the ISS on June 5, 2024, but NASA wanted them to stay up longer so their teams can study thruster failures and helium leaks on the new Boeing Starliner ship.
These two veteran US astronauts are the first to be sent up with the new Starliner. They've been in space for 64 days and counting.
Now the astronauts might not come back on the craft at all, NASA officials said in a press conference on Wednesday.
That's because there are lingering uncertainties about how safe the Boeing capsule is, so there's a chance Wilmore and Williams will watch their Starliner return to Earth empty.
'We could take either path'
Two more astronauts coming to the ISS on SpaceX's Crew-9 mission in late September would be left behind in February when that craft is supposed to come back, so Wilmore and Williams could take their seats.
NASA said they're also looking at another SpaceX craft as a backup, while additional experts look at the thruster failures aboard the Starliner.
"We could take either path,” said Ken Bowersox, NASA’s space operations mission chief.
“We heard from a lot of folks that had concern (in a recent meeting), and the decision was not clear,” Bowersox continued.
Steve Stich, NASA's commercial crew programme manager, said they've discovered that the Starliner's seals are one source of the thruster problems on the craft through ground testing.
There are still questions about how the thrusters would return to Earth, Stich continued, so they will work on modelling their use ahead of sending it back.
Engineers are still trying to understand how helium leaks happened in Starliner's propulsion system: a part of the craft that is crucial for maneuvering. One link, isolated and stable, happened before takeoff but others happened as it stayed in flight.
'We still believe in Starliner'
The Boeing Starliner is a partially reusable spacecraft that transports astronauts to and from the ISS in low orbit. It will eventually be used by NASA to conduct routine astronaut missions.
Boeing issued a brief statement following NASA's news update, repeating its position that the capsule could still safely bring the astronauts home.
“We still believe in Starliner’s capability and its flight rationale," the company said in a statement following the briefing.
ADVERTISEMENTA final decision on a return-to-Earth plan for Williams and Wilmore is expected by mid-August.
