NASA and SpaceX have confirmed Friday, April 18 for the next launch attempt for the Falcon 9 rocket to send the Dragon spacecraft on the company’s third commercial resupply mission and fourth visit to the space station. Launch is targeted for 3:25 p.m. ET. The launch will be webcast live at www.spacex.com/webcast beginning at 2:45 p.m. ET.
A launch on Friday results in a rendezvous with the space station on Sunday, April 20 and a grapple at 7:14 a.m ET.
During Monday’s launch attempt, pre-flight checks detected that a helium valve in the stage separation pneumatic system was not holding the right pressure. This meant that the stage separation pistons would be reliant on a backup check valve.
No issue was detected with the backup valve and a flight would likely have been successful, but SpaceX policy is not to launch with any known anomalies. We have brought the vehicle back to horizontal and are replacing the faulty valve, as well as inspecting the whole system for anything that may have contributed to the valve not working as designed.