NASA on Thursday released a detailed 311-page report that classifies the manned test mission of the Starliner spacecraft as a Type A accident, the agency’s most serious category of human spaceflight failure. The document points out technical flaws in the propulsion system, design and engineering deficiencies in spacecraft, as well as leadership and supervision problems both at Boeing and at NASA itself. Astronauts Butch Wilmore and
The investigation, concluded in November 2025, highlights that the mission planned for 8 to 14 days was extended due to anomalies that compromised safety and generated risks incompatible with the agency’s standards.
The report identifies a combination of hardware failures, gaps in vehicle qualifications and poor decisions that created unsafe conditions during the flight. NASA emphasizes that it will not fly crew again on Starliner until the technical causes are understood, corrected and the propulsion system is fully qualified, with implementation of the recommendations.
Main technical anomalies identified
Five service module maneuvering thrusters failed during approach to the ISS, resulting in temporary loss of control in six degrees of freedom. Quatro of them were recovered through on-site troubleshooting, allowing safe coupling. Probable causes include two-phase flow of the oxidizer with vaporization and cavitation, extrusion of the Teflon poppet in the valves, and excessive mechanical demands. A crew module thruster failed during descent, reducing fault tolerance to zero.
Seven of eight helium manifolds leaked throughout the mission, attributed to incompatibility of seal materials with the oxidizer and O-ring sizing problems. The propulsion system suffered from two-fault tolerance for deorbit burns, a design defect not detected until pre-launch.
Read a report of findings from the Program Investigation Team examining the Boeing Starliner Crewed Flight Test:https://t.co/mrjmnLrVUC pic.twitter.com/7tzGkpDxJ0
— NASA (@NASA)February 19, 2026
Criticisms of supervision and organizational culture
The investigation finds that NASA accepted insufficient verification data in lieu of qualifying tests representative of the mission. Programa’s culture of Tripulação Comercial prioritized provider success over technical rigor, with fragmented roles that delayed decisions. Reuniões techniques have become contentious, with reports of a hostile environment and lack of conflict resolution.
Boeing faced criticism for persistent engineering deficiencies and excessive reliance on subcontractors. The partnership between the organizations showed an erosion of trust, with differing risk assessments that created friction.
Recommendations and lessons for future programs
The report issues 61 formal recommendations in technical, organizational and cultural areas. Entre they are the requirement for qualifying tests that reflect all mission environments, improvement in the telemetry sampling rate for anomaly detection and correction of fault tolerance gaps. The investigation highlights the need for cultural alignment between NASA and providers to avoid recurring acceptance of anomalies without a root cause.
Impact on commercial crew program
NASA reduced the contract with Boeing and cut planned flights, bringing the ISS closer to retirement in 2030. The agency reinforces the importance of maintaining two American vehicles for transport to the station, with SpaceX taking the lead role after consistent successes. The Starliner remains under analysis for a possible unmanned flight in April.
Details about the astronauts and mission outcome
Butch Wilmore, 63 at the time, accumulated 464 days in space across three missions and retired in August 2025 after 25 years at NASA. Suni Williams, aged 60, logged 608 days in three missions and retired in December 2025 after a 27-year career. The mission preserved crew safety but exposed critical vulnerabilities in the vehicle and supervision.
The report serves as a basis for corrections before any future manned flight, prioritizing technical excellence and transparent communication.
