The memo is not long, but even so it pulls no punches: Starliner has design and engineering deficiencies that must be corrected, but the most troubling failure revealed by this investigation is not hardware. It is decision making and leadership that, if left unchecked, could create a culture incompatible with human spaceflight. It is worth restating what should be obvious. At that moment, had different decisions been made, had thrusters not been recovered, or had docking been unsuccessful, the outcome of this mission could have been very different. As development progressed, design compromises and inadequate hardware qualification extended beyond NASA's complete understanding. Prior OFT thruster risk was never fully understood, corrective actions from OFT-1 were incomplete, and flight rationale was therefore inadequate. Witness statements routinely reflected a belief that the management within the Commercial Crew Program could only succeed if Starliner launched. Disagreement over crew return options deteriorated into unprofessional conduct while the crew remained on-orbit. Witness statements described an environment where advocacy tied to Starliner program viability persisted alongside insufficient senior NASA leadership engagement to refocus teams on safety and mission outcomes. Despite the loss of six-degree-of-freedom control and cost thresholds exceeding a Type A mishap by a factor of one hundred, a mishap was not declared. Concern for the Starliner program's reputation influenced that decision. 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. Transparency is not a weakness. It is a strength. We will release the investigation in full, redacted only where legally required and as directed by our commercial partner. Pretending unpleasant situations did not occur teaches the wrong lessons. Failure to learn invites failure again and suggests that, in human spaceflight, failure is an option. It is not. America entrusts NASA with the hardest endeavors ever attempted. The world looks to us for the discoveries, achievements, and leadership only this agency can deliver, and that requires putting the mission and the crew first. Note: The reference to 'six degrees of freedom' is to the six types of change a spacecraft can make to its orientation and position. Three are rotations (pitch, roll and yaw) and three are translations (forward/aft, left/right and up/down). To have full control a spacecraft must be able to execute manoeuvres either way in all six. This is done by ensuring that the thrusters used for such manoeuvres are physically duplicated with separate (and often cross-connected) propellant lines. During the docking with ISS, Starliner temporarily lost both main and backup ability to thrust forward, which is bad at any time but very, very bad when you are approaching a 400 ton space station the size of a football field.



