Astronauts Butch Wilmore and Sunita Williams aboard the International Space Station
National Aeronautics and Space Administration (NASA)
NASA astronauts Butch Wilmore and Sunita Williams may remain aboard the International Space Station (ISS) until February 2025, due to issues with their spacecraft. This is the first crewed test flight of Boeing’s Starliner capsule, and it’s not yet clear whether it will be safe for Wilmore and Williams to return in it.
Starliner was scheduled to launch on June 5 and dock with the ISS for about a week before returning the astronauts to Earth. The launch was delayed by a myriad of minor issues with the spacecraft, including a small helium leak on the day of launch, which engineers determined would not cause any further delays.
However, before reaching the ISS, another helium leak occurred and five of Starliner’s 28 thrusters failed. Wilmore and Williams made it aboard the ISS safely, but their future remains unclear one month after their planned return to Earth.
“When we launched this mission, it was a test mission,” NASA’s Ken Bowersox said at a press conference on August 7. “We knew it was potentially riskier than flying a more experienced spacecraft.” Currently, there’s disagreement within NASA about whether the risks of additional leaks or thruster failures on the return flight are too high to put people on Starliner again, he said.
During the press conference, NASA’s Steve Stich said a big part of the risk assessment is trying to replicate in ground tests the problems Starliner experienced in space. Stich said some progress has been made, but it’s still not enough to significantly reduce the uncertainty about how Starliner will perform on its return to Earth. “We can’t prove with absolute certainty that what we’re seeing in orbit is exactly the same as what we’re seeing on the ground,” Stich said.
Of course, this doesn’t mean Wilmore and Williams will be stuck on the ISS forever. There is a contingency plan: If NASA determines the risk to Starliner is too high, the Starliner’s software will need to be reconfigured to allow it to return to Earth autonomously and unmanned. Then, SpaceX’s Crew Dragon capsule, currently docked to the ISS, will be reconfigured to carry two additional astronauts.
But that’s not the primary option. There are also plans to use the next Crew Dragon spacecraft to bring astronauts back to Earth, although that launch date was just postponed to September. It was originally scheduled to carry four astronauts to the ISS, but it may only carry two, leaving room for Wilmore and Williams when the mission ends in February 2025.
Wilmore and Williams are training for all activities planned for the mission, including spacewalks, which would extend their stay in space from the planned eight days to nearly eight months. NASA has already directed SpaceX and Boeing to begin work on the upgrades needed to make either plan viable, but no selections have been made yet.
“These are backup contingency plans,” ISS manager Dana Weigel said at a press conference. “No decisions have been made yet in terms of sticking to a specific plan.” Stich said a decision is likely to be made in mid-August. The larger impact of this dispute on NASA’s commercial crew program remains to be seen.
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