SpaceX Identify Rocket Engine Issue That Caused Last-Second Abort

SpaceX has identified the Falcon 9 Merlin rocket engine issue that forced a last-second abort of the Space Force GPS IIIA-04 mission earlier this month.

During an October 29 briefing, Hans Koenigsmann, SpaceX vice president of build and flight reliability, explained that “masking lacquer” had blocked a relief valve in the Merlin engine’s gas generator, which utilises small amounts of fuel and oxidiser to power the engine’s turbopumps.

Koenigsmann, explained that the lacquer is utilised by a contractor to protect select surfaces of aluminium components when they are anodised, a process that protects the parts from corrosion.



The lacquer is supposed to be removed with a cleaning fluid once the process is complete. However, SpaceX has identified at least three engines where the lacquer was not adequately removed.

Two of the three engines that have been identified were installed onto the Falcon 9 first stage booster that is expected to be utilised for the first operational mission of the Crew Dragon spacecraft, designated Crew-1. SpaceX has since replaced the affected engines on the Crew-1 booster and another on a booster that is expected to carry NASA’s Sentinel-6 Michael Freilich climate satellite into orbit on November 10.

The launch of the Crew-1 mission had initially been slated for October 31. The last-second abort in early October prompted NASA to push the launch to an unspecified date in early to mid-November.

In an October 26 statement, NASA announced that the agency was now targeting November 14 for the launch of Crew-1. However, NASA Associate Administrator of the Human Exploration and Operations Mission Directorate, Kathy Lueders, revealed that the agency would be keeping a close eye on the November 10 launch of the Sentinel-6 mission before making a final decision on when to launch Crew-1.

The launch of the Crew-1 mission received another hurdle during the October 29 briefing with NASA commercial crew program manager, Steve Stich, suggesting that the agency would prefer to review the outcome of the GPS 3 mission, which is expected to be launched on November 4, before making a decision.

NASA’s SpaceX Crew-1 mission is expected to carry a crew of four to the International Space Station. The mission will be the first operational flight of the SpaceX Crew Dragon spacecraft, which completed its first crew demonstration flight in August splashing down safely in the Gulf of Mexico with NASA astronauts Doug Hurley, Bob Behnken.