The liftoff of an Atlas 5 rocket set to carry the robotic X-37B Orbital Test Vehicle (OTV-3), which looks like a mini space shuttle, has now been slipped to Nov. 27, pending confirmation that the rocket range can support the launch.
According to a statement today from spokesperson Jessica Rye of United Launch Alliance (ULA), which builds the Atlas 5, the leadership at ULA and the Air Force agreed to postpone the launch of the X-37B for two weeks.
The postponement stems from an ongoing investigation of an engine glitch during an Oct. 5 flight of a Delta 4 booster, a relative to the Atlas 5. That launcher experienced a lower-than-normal upper-stage engine chamber pressure when it launched to place a Global Positioning System (GPS) IIF-3 spacecraft into orbit. [Photos: The X-37B Space Plane Unmasked]
Holding off on the liftoff of the Atlas 5 will allow for additional flight data anomaly investigation activities of the Delta 4 engine glitch and a thorough "crossover assessment" for the X-37B OTV launch vehicle, officials said.
Although the Atlas 5 that's being readied to propel the unpiloted OTV-3 into Earth orbit utilizes a different model of the Pratt & Whitney Rocketdyne RL-10 engine than the Delta 4, Air Force Space Command commander Gen. William Shelton asked for a discretionary accident investigation board (AIB) to investigate why the Delta 4 RL-10B-2 upper-stage engine did not perform as expected. As its standard process, the Air Force reviews all flight data to determine if it's ready to proceed with the next liftoff.
"This flight data anomaly investigation is being conducted with investigative processes that have been refined over decades of launch experience and include extensive reconstruction of the flight data with analytical models, as well as detailed inspections of several engines," Rye said in a statement Friday.