The failure of Boeing’s Starliner crewed test flight to the ISS in June 2024 has not deprived NASA of hopes of having a backup for crewed missions. Relying solely on SpaceX’s Dragons would be risky. The Starliner mission made that abundantly clear: having only one ship in reserve means putting the station’s crew at risk. So the path to certification for Boeing’s ship will continue, although its future remains uncertain.
Image source: NASA
Yesterday, astronauts Barry Wilmore and Sunita Williams, the pilots of the ill-fated Starliner, along with their colleagues, Roscosmos cosmonaut Alexander Gorbunov and NASA astronaut Nick Hague, returned to Earth on SpaceX’s Crew Dragon. Wilmore and Williams spent about nine months on the station, although their mission was originally supposed to last only ten days. The Boeing Starliner capsule that brought them there malfunctioned on its final approach to the ISS, and after studying the situation, NASA decided to return it to Earth without a crew.
The Starliner’s propulsion system suffered a helium leak, causing five of its 28 orbital correction thrusters to fail. Four of them were later restarted, but one remained inoperative. An investigation of the problem in a lab on Earth showed that the thrusters were overheating, causing the Teflon seals in the fuel system to deform. It is clear that the design or materials of the seals will have to be changed if Starliner is to be tested again.
A test of the updated helium supply system for the thrusters is expected this summer. “I think we need to make some changes to how we heat these thrusters, how we fire them, and then we can test that on the next flight,” said Steve Stich, NASA’s Commercial Crew Program Manager. “We need to make sure we can fix the helium leaks and also the service module thruster issues that we had during docking.”
«”We really need Boeing to be involved in crew,” Stich added. “Bringing Butch and Suni back on Dragon, I think, shows how important it is to have two different crew transportation systems, and the importance of Starliner and the redundancy we’re building into crew to support the economics of low Earth orbit.”
Plans for another test launch of the Starliner capsule remain uncertain. It is unclear when exactly it will happen or whether there will be a crew on board.