After more than two months of tests and discussions, NASA has decided that astronauts Butch Wilmore and Suni Williams will come home in February 2025 on a SpaceX Crew Dragon, and the Boeing Starliner they flew to the International Space Station on in June will return uncrewed. In a press conference on Saturday, Steve Stich, manager for NASA’s Commercial Crew Program, said “there was too much uncertainty” around the predictions for Starliner’s thrusters to move forward with a crewed return flight.

The plan now is that Starliner’s first crew will return with SpaceX’s Crew-9, which is scheduled to launch to the ISS at the end of September. Crew-9 was initially supposed to carry four crew members, but will instead have to go ahead with two, so as to make room for Wilmore and Williams on the way back. That spacecraft is being reconfigured with seats for the two astronauts, and Dragon spacesuits will be added to its cargo for them to wear home. By the time Wilmore and Williams depart, the duo will have been on the space station for about eight months. The Starliner flight test was only supposed to last a little over a week.

The next step is to get Starliner ready for undocking and wrap up as an uncrewed flight test. The agency plans to conduct the second part of its readiness review for the process this coming week, and expects undocking to take place around early next month. “We are changing the separation sequence that we planned and we will review those aspects at the readiness review,” Stich said. “We’re going to go with a simplified separation technique to get away from the station a little more quickly.”

The issue with Starliner’s thrusters has been “very complex,” Stich said, and their performance has been “challenging to predict.” Without being able to accurately predict how the thrusters would perform from undocking through the deorbit burn, the potential risks for the astronauts were just too high, he explained.

“We have had mistakes in the past,” said NASA Administrator Bill Nelson. “We have lost two space shuttles as a result of there not being a culture in which information can come forward.” With that context looming over the discussions, he said, “We have been very solicitous of all of our employees that if you have some objection, you come forward. Spaceflight is risky, even at its safest and and its most routine, and a test flight by its nature is neither safe nor routine. And so the decision to keep Butch and Suni aboard the International Space Station and bring the Boeing Starliner home uncrewed is the result of a commitment to safety.”

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