United Launch Alliance has announced a delay for the first crewed Starliner launch, with the new launch date set for no earlier than May 17th at 6:16 pm ET. The delay was triggered by an issue with the upper-stage liquid oxygen pressure relief valve, which did not fully close as astronauts Butch Wilmore and Suni Williams were being loaded into their capsule. ULA had hoped to resolve the issue at the pad, but due to the need for valve replacement, the rocket will be rolled back to the Vertical Integration Facility for access to the Centaur upper stage. It was stated by ULA’s CEO Tory Bruno that the upper stage needs to be “stretched” to depressurize Centaur before technicians can replace the valve due to the flight rules that prohibit changes to the rocket’s fuel state for safety reasons when astronauts and launch personnel are at the pad.
This delay represents the latest setback for Boeing’s Starliner capsule, originally slated for a crewed flight test in 2017. However, various issues, including a near loss of the vehicle on the first orbital flight test, necessitated a second successful OFT before encountering further problems such as flammable tape removal, parachute issues, and software reviews in the lead-up to the Crewed Flight Test. Once the valve is replaced, the rocket will be returned to the launch pad for the May 17th launch attempt. Throughout the delay, both astronauts will remain in quarantine as they await their journey to the International Space Station.