The planned June 1 launch of Boeing's CST-100 Starliner spacecraft was scrubbed just minutes before liftoff due to a ground computer issue, delaying the mission by at least four days. The problem arose when one of the three redundant ground control computers, specifically the launch sequencer, responded slower than the others, triggering an automatic hold. The incident occurred at T-3 minutes and 50 seconds, and despite having spare components, further examination and repairs were deemed necessary, ruling out a June 2 launch attempt.
Additional minor issues were also noted during the countdown. Two hours before the scheduled launch, a problem with the valves controlling liquid oxygen and hydrogen flow into the Centaur upper stage was resolved by switching computer racks. A subsequent issue with fans in the astronauts’ pressure suits was quickly fixed by switching the spacecraft to internal power.
A previous helium leak did not pose a problem this time, with acceptable leak rates observed. NASA and Boeing officials expressed disappointment but emphasized professionalism and readiness to address the issues.
Should the launch be delayed beyond June 6, United Launch Alliance (ULA) would need approximately 10 days to replace the rocket's batteries, further postponing the mission. NASA aims to complete Starliner's certification by late 2024, with the operational Starliner-1 mission slated for early 2025.