The findings, published as part of NASA’s Commercial Crew Program investigation, mark one of the most serious official rebukes of a human spaceflight mission in recent years and underscore ongoing challenges with Starliner, which was intended to serve as a second crew transport system alongside SpaceX’s Crew Dragon.
NASA administrator Jared Isaacman said the agency was taking full responsibility for the failures and implementing sweeping corrective actions to ensure such issues do not occur again.
“The Boeing Starliner spacecraft has faced challenges throughout its uncrewed and most recent crewed missions,” Isaacman said.
“To undertake missions that change the world, we must be transparent about both our successes and our shortcomings. We have to own our mistakes and ensure they never happen again.”
Starliner launched on 5 June 2024 aboard a United Launch Alliance Atlas V rocket on its long-awaited first crewed test mission to the International Space Station.
The mission, originally planned to last between eight and 14 days, was dramatically extended to 93 days after engineers detected propulsion system anomalies while the spacecraft was in orbit.
The issues emerged during Starliner’s approach to the station, when a combination of thruster malfunctions and propulsion system degradation compromised the spacecraft’s manoeuvrability. The loss of full control authority raised serious safety concerns during the critical docking phase of the mission.
Following extensive analysis and ground testing at NASA’s White Sands Test Facility in New Mexico, the agency made the unprecedented decision to return Starliner to Earth without its crew aboard.
NASA astronauts Butch Wilmore and Suni Williams remained on the space station while Starliner autonomously returned to Earth in September 2024, landing safely at White Sands Space Harbor.
The astronauts later returned to Earth in March 2025 aboard SpaceX’s Crew-9 mission, highlighting the importance of having a second operational crew transport system.
NASA convened an independent program investigation team in February 2025 to examine the technical, organisational and cultural factors that contributed to the mission’s failures. The final report, completed in November 2025, identified a combination of hardware deficiencies, qualification shortfalls, leadership misjudgements and cultural breakdowns.
Investigators concluded that multiple failures interacted to create risk conditions inconsistent with NASA’s strict human spaceflight safety standards.
In particular, the report found that broader programmatic pressures, including NASA’s strategic objective of maintaining two independent crew transport providers, influenced engineering and operational decisions before, during and after the mission.
NASA acknowledged that these institutional priorities contributed to decisions that, in hindsight, did not fully align with the agency’s safety-first culture.
“Beyond technical issues, it is clear that NASA permitted overarching programmatic objectives … to influence engineering and operational decisions,” Isaacman said.
NASA’s classification of the mission as a Type A mishap represents the highest level of incident severity in the agency’s safety framework.
Type A mishaps are defined as incidents involving the potential for loss of life, permanent disability or major system loss, typically accompanied by significant financial consequences.
While no injuries occurred and mission control ultimately regained sufficient spacecraft control to complete the docking safely, NASA determined that the severity of the propulsion failures and loss of manoeuvrability warranted the designation.
The classification reflects both the technical seriousness of the anomalies and the potential consequences had recovery actions failed.
NASA and Boeing have been working jointly since Starliner’s return to identify root causes and implement corrective measures, but the investigation confirms that substantial work remains before the spacecraft can safely resume crewed operations.
The report emphasised the need for technical redesigns, improved system qualification, strengthened engineering oversight and cultural reforms within both NASA and Boeing’s program management structures.
NASA said Starliner will not fly again until all technical and organisational deficiencies identified in the investigation have been fully addressed.
The spacecraft was developed under NASA’s Commercial Crew Program to provide independent access to orbit following the retirement of the Space Shuttle fleet in 2011. The program funded two industry partners, Boeing and SpaceX, to ensure redundancy and resilience in crew transportation.
While SpaceX’s Crew Dragon has conducted multiple successful operational missions since 2020, Starliner has faced repeated delays, technical setbacks and cost overruns.
The investigation’s findings highlight the risks associated with developing complex human-rated spacecraft through commercial partnerships, particularly when programmatic timelines and strategic objectives intersect with engineering and safety decisions.
Despite the setbacks, NASA reaffirmed its commitment to Starliner as a critical component of its long-term human spaceflight architecture.
The agency said it would continue working closely with Boeing to implement corrective actions and safely return the spacecraft to flight.
The investigation represents a pivotal moment for the program, reinforcing NASA’s longstanding principle that crew safety must remain paramount, regardless of cost, schedule or strategic pressures.
As NASA prepares for an increasingly ambitious human spaceflight agenda, including sustained lunar missions and eventual journeys to Mars, the lessons learned from Starliner’s troubled test flight are likely to shape spacecraft development, oversight and risk management for years to come.