For much of last year, the extent of the difficulties with Boeing's Starliner spacecraft, docked at the International Space Station (ISS), remained largely unknown. A safety advisory panel revealed that even NASA's workforce was affected by this uncertainty.
On its initial Crew Test Flight, Boeing's Starliner transported NASA astronauts Butch Wilmore and Suni Williams to the ISS in June 2024. They were the first crew to fly aboard the Starliner after more than ten years of development and setbacks. Although the astronauts planned to stay at the ISS for just one or two weeks, they ultimately spent nine months in orbit. NASA officials judged it too risky to bring them back to Earth in the Boeing-built capsule, and Wilmore and Williams eventually returned last March aboard a SpaceX Dragon spacecraft.
The Starliner capsule encountered issues with its maneuvering thrusters and helium leaks during its 27-hour journey from the launch pad to the ISS. At one point, Commander Wilmore lost the ability to control the spacecraft's movements as it approached docking at the ISS in June 2024. Engineers found some thrusters were overheating but managed to restore much of their functionality, permitting the Starliner to successfully dock with the ISS.
“There was concern in real time that without recovery of some control, neither a docking nor a deorbit could be controllable, and that could have led to loss of vehicle and crew,” said Charlie Precourt, a former space shuttle commander and a member of NASA's Aerospace Safety Advisory Panel (ASAP). “Given the severity of this anomaly, NASA wisely and correctly used the safe haven of the ISS to conduct testing and engineering on the ground to analyze the various recovery options.”
Throughout the summer, NASA and Boeing managers reassured that the spacecraft was safe for an emergency return of Wilmore and Williams. However, comprehensive testing was ordered to diagnose the issues thoroughly. Beneath the headlines, there was the distinct possibility that NASA might decide — as they ultimately did — not to risk using the Boeing-built crew capsule to ferry astronauts back to Earth from the ISS.