NASA faults Boeing Starliner but keeps program

NASA has released a 311-page report on Boeing’s (BA) CST-100 Starliner following the troubled 2024 Crewed Flight Test (CFT), which left astronauts on the International Space Station (ISS) for months longer than planned. The mission ended with the crew returning on a SpaceX spacecraft, and Starliner has not flown since.

The report, titled "Starliner Propulsion System Anomalies during the Crewed Flight Test Investigation Report," concludes that a combination of technical, organizational, and cultural factors contributed to the failed test. NASA classified the CFT as a "Type A mishap" and described it as a "mission failure" after Starliner lost flight control during docking.

NASA associate administrator Amit Kshatriya said, "we almost did have a really terrible day," underscoring the severity of the problems uncovered during the mission.

Investigators identified four major hardware issues with Starliner’s propulsion system. Five thrusters on the service module and one thruster on the crew module failed during the mission, undermining maneuvering capability.

Seven of eight helium manifolds were found to have leaky seals, raising concerns about reliability of the pressurization system. NASA also cited a lack of redundancy in the propulsion design, warning that multiple material failures could have prevented a safe return to Earth.

Beyond hardware, NASA criticized Boeing’s (BA) testing regime and its handling of prior anomalies, stating that inadequate testing and misdiagnosis of earlier issues contributed to the CFT outcome. NASA also faulted its own oversight of Boeing’s work.

In response to the findings, NASA issued 61 formal recommendations addressing the critical vulnerabilities in the spacecraft, Boeing’s development processes, and NASA’s oversight practices. These recommendations aim to resolve both technical defects and broader organizational shortcomings.

NASA administrator Jared Isaacman stated that "NASA will not fly another crew on Starliner until technical causes are understood and corrected, the propulsion system is fully qualified, and appropriate investigation recommendations are implemented." Until then, any future use of Starliner could be limited to uncrewed cargo missions, or paused entirely.

Despite the severity of the report, NASA has not canceled the Starliner program. Isaacman emphasized that "America benefits from competition and redundancy," pointing to the strategic importance of having more than one crew transport provider for the ISS.

NASA wants to avoid relying solely on SpaceX’s Falcon 9 and Crew Dragon for ISS access. Maintaining Starliner as a viable option is intended to protect against potential grounding of a single system and to preserve price competition, so that SpaceX does not become NASA’s only option or set terms without a competitor.

Boeing’s Commercial Crew contract, awarded in 2014 and valued at $4.2 billion for six crewed missions, is now under time pressure, with the remaining lifespan of the ISS limiting how many flights can still be flown once Starliner is deemed ready.

NASA’s Commercial Crew framework originally envisioned Boeing flying six crewed ISS missions, matching SpaceX’s six missions, though SpaceX received a smaller $2.6 billion award and has already flown 13 crewed missions with another scheduled.

At NASA’s current pace of about two crewed flights per year and with the ISS planned to retire after 2030, or possibly 2032 if extended, there may be room for roughly nine to 13 more crewed flights in total. The timing of any Starliner return to service will therefore influence how many of Boeing’s contracted missions can still be executed.

If ISS operations end in 2030 and Starliner is not ready soon enough, Boeing could miss out on a portion of the $4.2 billion contract value, with potential revenue shortfalls discussed in the context of lost missions and delayed readiness.