November 05, 2012
Credit: Credit: United Launch Alliance
The U.S. Air Force has further delayed boosting its third Orbital Test Vehicle mission by two weeks to allow more time to investigate an anomaly in the RL10 upper-stage performance in the last launch.
The launch of the reusable X-37B spacecraft on the OTV-3 mission has now been slipped to Nov. 27, according to the United Launch Alliance, which manages the Atlas and Delta rocket families.
During an Oct. 8 launch of the Boeing GPS IIF spacecraft, the Delta IV was observed to have “lower than normal upper-stage engine chamber pressure.” The satellite made it to its intended orbit, but the Air Force convened an accident investigation board to ensure the problem is not systemic. Pratt & Whitney Rocketdyne manufactures the RL10.
The additional two weeks before the OTV-3 launch is needed in part to conduct a “thorough crossover assessment,” as the OTV-3 will be launching on an Atlas V. The Delta IV uses the ARL10B-2, while the Atlas V uses the RL10A. But, operators want to ensure there is no common problem between the two.