ULA Still Investigating Atlas V OA-6 Anomaly

OA-6/Atlas V being rolled out to Pad 41 for launch. Image Credit: NASA/Ben Smegelsky

OA-6/Atlas V being rolled out to Pad 41 for launch. Image Credit: NASA/Ben Smegelsky

March 31, 2016 – United Launch Alliance (ULA) of Centennial, Colorado, released an update today on the investigation into an Atlas V flight anomaly that occurred during the launch of the OA-6 Cygnus spacecraft on Tuesday, March 22.

Although the Cygnus spacecraft reached the desired orbit and later docked with the International Space Station as planned, the Atlas V rocket experienced a premature first stage shutdown. The first stage cut-off occurred approximately 6 seconds early, but the Centaur automatically compensated by burning longer, and the system achieved mission success.

ULA and its partners have formed a robust review team – standard practice when a flight anomaly has been identified – and the team is continuing to review the data. The engineering team has traced the problem to the first stage fuel system and its associated components and will continue to assess the flight and operational data to determine the root cause.

This was the 133rd successful launch in a row for Atlas and the 62nd for Atlas V. The Atlas V has been used to launch 24 Department of Defense flights, 13 commercial missions, 12 for NASA and 12 for the National Reconnaissance Office.

ULA’s next launch is the MUOS-5 satellite for the U.S. Navy. The launch has been rescheduled from May 5 to May 12 to give the company more time to investigate the cause of the anomaly. MUOS-5 will be launched on a Delta IV Heavy rocket.