United Launch Alliance (ULA) announced that it has cleared the X-37B Orbital Test Vehicle for launch atop one of the company’s Atlas V 501 rockets on Dec. 11, 2012. This follows a thorough review of a technical issue that appeared during the launch of a Delta IV Medium launch vehicle on Oct. 4.
The Delta IV and Atlas V family of rockets share similar engines in their upper stages. During the launch of the Global Positioning System (GPS) IIF-3 this past October, one of the RL-10 engines experienced a lower-than-normal engine chamber pressure.
“Although the GPS mission was successful and the satellite was delivered to a precise orbit, ULA and Pratt & Whitney Rocketdyne (PWR) are executing an extremely robust investigation into the cause of the reduced engine performance on the recent Delta IV mission,” said Jim Sponnick, ULA vice president of mission operation. “Our 50-year heritage of launch experience and decades of launch data have enabled the robust investigation processes we perform for any flight conditions that differ from our nominal predictions, in order to continue the critical focus on mission success that our customers demand.”
ULA has determined that a fuel leak occurred in the interior of the thrust chamber which began during the first engine start sequence. The launch of OTV-3 still remains “no-earlier-than” as the investigation into the anomaly is ongoing. However, all the data that the team has acquired so far suggests that any crossover issues have been resolved.
“Our flight data anomaly investigation includes substantial involvement and oversight from senior industry technical advisors, as well as our Air Force OTV customer, Air Force EELV customer, and NASA customers,” said Sponnick. “We thank the OTV customer for their patience and participation throughout the flight clearance process for this important mission.”
If everything goes according to plan, ULA will launch the TDRS-K mission on Jan. 29, 2013, for NASA. This next mission for Colorado-based ULA will also journey to orbit using the venerable Atlas launch vehicle.
The X-37B is the U.S. Air Force’s secretive space plane; it has been launched twice before, both times from Cape Canaveral Air Force Station’s Space Launch Complex-41, located in Florida.