Discovery Roll Out to Pad 39A Delayed Until Tuesday

During prerollout preparations and testing Saturday morning in NASA Kennedy Space Center’s Vehicle Assembly Building, a valve failed inside space shuttle Discovery’s left-hand solid rocket booster hydraulic power unit tilt system, which helps steer the SRBs during launch. (The specific hardware was the check valve filter assembly, or CVFA )

The additional time to evaluate the issue has pushed Discovery’s rollout to Kennedy’s Launch Pad 39A to Tuesday, Aug. 4 at 12:01 a.m. EDT instead of Monday.

Any work to replace the valve and associated hardware will be done at the launch pad. Managers are assessing how to integrate the additional work with standard prelaunch processing activities.

The astronauts for Discovery’s STS-128 mission to the International Space Station still are scheduled to begin their launch dress rehearsal and related training Wednesday, Aug. 5. The Terminal Countdown Demonstration test, as the rehearsal is known, is set to conclude Friday, Aug. 7.

Discovery remains targeted for launch no earlier than Aug. 25.