The two astronauts were supposed to leave for eight days in space, but they’ll be there for eight months: Butch Wilmore and Suni Williams, who flew to the International Space Station on Boeing’s Starliner spacecraft, will return to Earth in February on a Boeing spacecraft competitor SpaceX, NASA announced Saturday.

Successive difficulties encountered with the Starliner led to the difficult decision not to use that spacecraft to bring the two American astronauts back to Earth. A blow to Boeing, already bogged down by repeated failures of its planes.

“NASA has decided that Butch and Suni will return with Crew-9 next February and that Starliner will return without a crew,” NASA Administrator Bill Nelson said at a press conference at the end of a decision-making committee meeting. on Saturday.

He justified the decision as a safety precaution, but said he was still counting on the SpaceX-Boeing duo to carry astronauts into space, saying he was “100 percent” sure Boeing would see to it that the Starliner would launch manned again.

Astronauts Butch Wilmore and Sonny Williams were aboard the Starliner in early June when their journey began and have been aboard the International Space Station ever since, where their spacecraft has remained tethered.

Starliner was originally supposed to bring them back to Earth eight days later, but problems identified with the propulsion system led NASA to question its reliability. And to consider a radical emergency solution: bringing back its passengers, who have already spent two and a half months in the flying lab, with a regular SpaceX mission in February.

For weeks, Boeing and NASA teams have been conducting tests to better understand the cause of the in-flight problems, mainly with the spacecraft’s thrusters. The main concern is that the Starliner might not be able to generate the thrust needed to exit orbit and begin its descent toward Earth.