Air Force Space Command (AFSPC) chief Gen. William Shelton has ordered an Accident Investigation Board (AIB) to investigate why an upper stage engine on a Delta IV RL-10B-2 rocket did not perform as expected during the Oct. 4 launch of a GPS IIF satellite, according to a service statement.
“While the launch was ultimately successful, 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,” Shelton said in a statement. “In the end, our objective is continued safe and reliable launch for our nation.”
During the launch, the RL-10B-2 second stage engine did not perform as expected even though the Delta IV delivered the GPS IIF satellite into its proper orbit.
Per standard processes, the Air Force carefully reviews all flight data to determine readiness to proceed with the next launch. Therefore, the launch manifest schedule is currently under review while the root cause of the unexpected performance of the RL-10B-2 engine is determined.
Once the AIB completes the investigation, it will report its findings to Shelton and, as appropriate, make them available to the public.
The Delta IV rocket was manufactured by United Launch Alliance, a joint venture between Boeing [BA] and Lockheed Martin [LMT].