Orbital ATK to finish rocket explosion probe by end March: CEO

By Andrea Shalal WASHINGTON (Reuters) - Orbital ATK expects to complete an investigation into the Oct. 28 explosion of its Antares rocket by the end of March, the company's chief executive said on Thursday. Orbital CEO David Thompson, speaking after an event hosted by the National Defense Industrial Association, said the investigation was nearly complete, but he declined to give details. The explosion destroyed a cargo ship bound for the International Space Station. The company last month said the "accident investigation board," which includes officials from NASA and the Federal Aviation Administration, had identified a number of credible causes for the explosion, including the possible presence of foreign object debris in the rocket's engine. GenCorp Inc's Aerojet Rocketdyne unit refurbishes Soviet-era NK-33 engines and resells them as AJ-26 motors for the Antares rockets, but Orbital had already announced plans to shift to a different motor even before the accident. Separately, Thompson welcomed a request for information from the Air Force, which is seeking to end U.S. reliance on a different Russian-built engine, the RD-180. It powers the Atlas 5 rockets that are used to launch national security satellites. Thompson said Orbital planned to respond to the request, which indicated that the Air Force may kick off a multibillion-dollar competition for 28 launches of government satellites, instead of focusing narrowly on development of a new rocket engine. "I think there's some real opportunities here to achieve both lower costs and less international dependence," Thompson said. Company responses are due by March 20. Congress, concerned about tensions between Washington and Moscow over Russia's annexation of the Crimea region of Ukraine, last year passed a law requiring the Air Force to end reliance by 2019 on the RD-180 engine. The new Air Force document, however, was looking at initial launches of the rockets no later than 2022. (Reporting by Andrea Shalal; Editing by Grant McCool)