Boeing Starliner Crew Flight Test thruster failures
Boeing's first crewed Starliner flight suffered multiple thruster failures approaching the ISS; NASA ultimately decided to return the capsule uncrewed and keep the two astronauts on the station for an extra nine months, awaiting a SpaceX flight home.
The damage was public. The root cause was preventable.
Boeing's first crewed Starliner flight suffered multiple thruster failures approaching the ISS; NASA ultimately decided to return the capsule uncrewed and keep the two astronauts on the station for an extra nine months, awaiting a SpaceX flight home.
What the software actually got wrong
Overheating caused Teflon seals in the propulsion system's doghouse thrusters to swell and restrict propellant flow; the thruster-control software's response to the resulting thrust irregularities, and NASA's inability to fully model the failure in time, drove the decision not to trust the capsule for a crewed return.
Overheating caused Teflon seals in the propulsion system's doghouse...
Overheating caused Teflon seals in the propulsion system's doghouse thrusters to swell and restrict propellant flow
Requs AI Edge Case flags this exact pattern at the requirements and architecture stage — before a single line of code implementing it exists — so the assumption behind it gets challenged while it is still cheap to fix.
The thruster-control software's response to the resulting thrust irregularities
the thruster-control software's response to the resulting thrust irregularities
Requs AI Software FMEA traces this failure mode back to the system-level hazard it feeds, tagging it against the Common Defect Enumeration so it surfaces in review instead of in the field.
NASA's inability to fully model the failure in time,...
NASA's inability to fully model the failure in time, drove the decision not to trust the capsule for a crewed return
Requs AI Edge Case and Software FMEA together treat this as a known, catalogued defect pattern — not a novel surprise — so it gets tested for deliberately rather than discovered after deployment.
Beyond code coverage and "shall" testing
Root causes like this one rarely show up in code coverage or requirements-compliance testing, because nobody wrote a requirement anticipating the specific edge case that broke. Requs AI Edge Case and Requs AI Software FMEA are built to surface exactly this class of overlooked failure mode — before the software is written.
Surfaces this before code exists
Identifies edge cases like this one at requirements and architecture time, using the Common Defect Enumeration to catalog failure patterns seen across hundreds of real-world software failures — including this one.
Connects the failure mode to the hazard
Traces this class of root cause directly to the system-level hazard it can produce, so a defect pattern like this one gets flagged during design review instead of after it ships.
Find the overlooked root causes before they ship.
Schedule a demonstration, or explore how Requs AI Edge Case and Software FMEA use the Common Defect Enumeration.