BOEING: Starliner faced ‘catastrophic’ failure before software bug found. “If it had gone uncorrected it would have led to erroneous thruster firing.”

“While this anomaly was corrected in flight, if it had gone uncorrected it would have led to erroneous thruster firing and uncontrolled motion during SM separation for deorbit, with the potential for catastrophic spacecraft failure,” Hill said during the meeting.

Starliner’s December test flight had to be cut short due to a well-publicized timing error that delayed the spacecraft’s service module from performing an orbital insertion burn. This caused the thrusters on board the service module, which provides power to Starliner during most of its mission, to fire longer than expected. As a result, the spacecraft did not have enough fuel to complete a rendezvous with the International Space Station, a key component of the test flight in advance of crewed missions.

At Thursday’s meeting, Hill revealed the second issue related to software and thruster performance publicly for the first time.

However, as part of reporting on a story about Starliner software and thruster issues three weeks ago, a source told Ars about this particular problem. According to the source, Boeing patched a software code error just two hours before the vehicle reentered Earth’s atmosphere. Had the error not been caught, the source said, proper thrusters would not open during the reentry process, and the vehicle would have been lost.

What a mess.