SpaceX will instead bring Suni Williams and Butch Wilmore back in late February, stretching their original eight-day mission to more than eight months.
After months of turmoil over its safety, Boeing’s new astronaut capsule has departed the International Space Station bound for Earth without its crew on board.
NASA’s two test pilots – Suni Williams and Butch Wilmore – have stayed behind at the ISS which will be their home until next year.
“She’s on her way home,” Williams radioed to Mission Control after Starliner undocked 420 kilometres over China.
The capsule’s return flight is expected to take six hours, with a night time touchdown in the New Mexico desert.
Williams and Wilmore should have flown Starliner back to Earth in June, a week after launching in it.
But thruster failures and helium leaks marred their ride to the space station.
NASA ultimately decided it was too risky to return the duo on Starliner. So the fully automated capsule left with their empty seats and blue spacesuits along with some old station equipment.
SpaceX will bring the duo back in late February, stretching their original eight-day mission to more than eight months.
Boeing’s first astronaut flight caps a journey filled with delays and setbacks. After the space shuttles retired more than a decade ago, NASA hired Boeing and SpaceX for orbital taxi service.
Boeing ran into so many problems on its first test flight with no one aboard in 2019 that it had to repeat it. The 2022 do-over uncovered even more flaws and the repair bill topped $1 billion (€901 million).
Even before Williams and Wilmore launched on June 5, Starliner’s propulsion system was leaking helium. The leak was small and thought to be isolated, but four more cropped up after liftoff. Then five thrusters failed.
Although four of the thrusters were recovered, it gave NASA pause as to whether more malfunctions might hamper the capsule’s descent from orbit.
Boeing conducted numerous thruster tests in space and on the ground over the summer and was convinced its spacecraft could safely bring Wilmore and Williams home. But NASA disagreed and opted for SpaceX.
A minute after separating from the space station, Starliner’s thrusters could be seen firing as the white, blue-trimmed capsule slowly backed away. NASA Mission Control called it a “perfect” departure.
Flight controllers planned more test firings of the capsule’s thrusters following undocking. Engineers suspect the more the thrusters are fired, the hotter they become, causing protective seals to swell and obstruct the flow of propellant.
They won’t be able to examine any of the parts; the section holding the thrusters will be ditched just before re-entry.
NASA’s commercial crew program manager Steve Stich said earlier this week that teams have been so focused on Starliner’s return that they’ve had no time to think about what’s next for Boeing.
He said the space agency remains committed to having two competing US companies transporting astronauts.