Flight teams standing down due to valve issue on upper stage of launch vehicle.
UPDATE MAY 7, 2024: United Launch Alliance has decided to replace the Centaur liquid oxygen self regulating valve, which is a pressure regulation valve on the upper stage. To allow for the valve replacement work, the NASA-Boeing team is now targeting NET May 17 for the next launch opportunity. More details can be found on NASA’s Commercial Crew Blog here.
UPDATE: Boeing, NASA and United Launch Alliance have made the decision to allow engineering teams to spend Tuesday, May 7, evaluating the data and the next launch opportunity will be no earlier than Friday, May 10.
United Launch Alliance (ULA), with concurrence from Boeing and NASA, scrubbed the launch a little more than two hours ahead of the originally scheduled liftoff time of the CST-100 Starliner Crew Flight Test on Monday, May 6. NASA astronauts Butch Wilmore and Suni Williams safely exited Starliner and returned to crew quarters, following the decision to stand down from launch for the day.
The scrub was recommended after launch control teams detected anomalous behavior by the pressure regulation valve in the liquid oxygen tank of the Centaur upper stage of the ULA Atlas V launch vehicle. Engineers are analyzing the data to fully understand the issue and determine any corrective actions. Mission managers will convene to decide next steps and potential timing for another launch attempt.
Click here to watch a news conference with representatives from NASA, Boeing and United Launch Alliance discussing the scrub in more detail.