+Comment NASA has decided that the Boeing Starliner pilots stranded on the International Space Station will return to Earth next year in a SpaceX Crew Dragon capsule – after the US agency’s engineers failed to clear the Starliner’s engines for the return flight.

As a reminder, Boeing flew its Starliner capsule to the orbiting space station in June with two pilots on board. The mission was to last about a week. The astronaut couple Butch Wilmore and Suni Williams were to return home in this capsule. It was expected that they would be back by now.

However, their journey home was interrupted by NASA due to concerns about the engines and helium leaks in the Calamity capsule, leaving the duo stranded on the ISS with the rest of the crew.

After much deliberation and Boeing’s insistence that its equipment was safe enough, the official plan announced by NASA over the weekend now calls for the Starliner capsule to return to Earth uncrewed in early September.

Shortly thereafter, more or less as planned, a SpaceX Crew Dragon capsule will arrive as part of a mission called Crew-9. That mission was supposed to bring four more astronauts to the space station, but now it will only bring two, and the Starliner astronauts will then become part of Crew-9.

Crew-9 is not scheduled to return until February next year at the earliest, so the Starliner pair will have to stay on the station for months.

NASA has yet to confirm which of the four astronauts originally scheduled to fly with Crew-9 will have to give up their seats.

Not only is the decision a blow to Boeing, it also means that the existing Crew-8 capsule will have to temporarily serve as a lifeboat for six astronauts instead of four until Crew-9 arrives. According to NASA, the capsule’s cargo hold will be adjusted to accommodate the Starliner duo in an emergency.

During a press conference on August 25, NASA said the decision to return the crew in a SpaceX vehicle was unanimous within the American agency, but Boeing assumed the crew would be perfectly safe in their capsule.

Ultimately, it’s a question of known and unknown risks. The problems that have plagued the Starliner’s engines have proven to be too big a risk for NASA. According to NASA, the capsule’s engines are running hotter than expected, which could cause performance issues during the burn and deorbit maneuvers. Ultimately, the NASA team decided not to take the risk of sending a crew back in the Starliner.

The US space agency did not say whether the mission would be lost if the crew were not sent back. It also called the question of whether Starliner would be approved for use or another test mission would be required “premature.” It is highly unlikely that the next crewed launch of Boeing’s Starliner will take place before 2026.

At first glance, the decision to return the Starliner unmanned appears to be evidence of a change in practices and management style at NASA following the tragedies involving the space shuttles Challenger and Columbia, where concerns and disagreements about risks and safety were nipped in the bud, with disastrous consequences.

However, questions must be asked of both the agency and Boeing. Starliner was launched with known problems – helium leaks. Abnormal behavior of the engines had also been observed in previous unmanned flights.

Despite the problems, NASA carried out the launch.

Could the agency have done things differently? Hindsight is always 20/20, especially when you consider how difficult it was for engineers to replicate the problems encountered in space on Earth. But one also wonders if some employees got a little caught up in launch fever as the long-delayed manned launch date finally approached.

As it stands, NASA’s decision is a blow to Boeing. The US space agency remains committed to having two operational US crew transport systems, but there is now a real chance that the ISS could be in its final years before Boeing’s Starliner is finally certified. ®