Two Rocket Engine Anomalies Under Review

The Air Force has begun an investigation into the Delta IV second stage anomaly on October 4 just as SpaceX and NASA are beginning a completely separate look at why one of the nine engines on SpaceX’s Falcon 9 failed on October 7.

U.S. space launches have been so reliable recently that having two anomalies occur just days apart seems unusual, although that is not to suggest there is any common cause.

The Delta IV put the GPS II-F3 satellite into its correct orbit, but the United Launch Alliance (ULA) said that it “observed an unexpected data signature” signalling reduced thrust from the RL10 second stage engine.  The Air Force and ULA are waiting to better understand the problem before their next launch.   That mission, the Air Force’s X-37B Orbital Test Vehicle (OTV), was scheduled for liftoff on October 25 on an Atlas V.  Atlas V uses a different version of the RL10 engine, but ULA said it would not certify the rocket ready for launch until it understands what happened on the Delta IV.  ULA builds and launches both rockets.

Air Force Space Command Commander Gen. William Shelton set up an Accident Investigation Board (AIB) yesterday, saying “the time honored rigor and earnest process of an AIB will serve us well as we attempt to determine the root cause of this anomaly.”

Meanwhile, SpaceX announced today that a joint “CRS-1 Post-Flight Investigation Board” has been established with NASA to “methodically analyze all data in an effort to understand what occurred to engine 1” during Sunday’s launch of the Dragon spacecraft to the International Space Station (ISS).  Engine 1 failed during ascent.  The other eight engines on the Falcon 9 compensated and Dragon was delivered into its correct orbit, but a secondary payload, ORBCOMM OG2, was not and subsequently reentered.  This was the first Commercial Resupply Services (CRS) mission for SpaceX, and Dragon is now snugly berthed with the ISS.

SpaceX and NASA had been planning for the next SpaceX CRS mission in January.   It is not clear at this point if that launch date will hold. SpaceX is under contract to NASA to launch 12 CRS missions to the ISS between now and 2015.