Orbital Sciences set to retire suspect motor in rocket explosion

An investigation into the explosion last week of Orbital Sciences’ Antares rocket pointed to a likely problem with a turbopump in the booster’s main engine, a refurbished Soviet-era motor that Orbital expects to discontinue, the company chief executive said on Wednesday.
 
The unmanned rocket, which was carrying a cargo ship to the International Space Station for NASA, exploded about 15 seconds after liftoff from Virginia on Oct. 28, the first of two recent accidents by privately owned U.S. space operators.
 
To fulfill its contractual obligations to NASA, Orbital Sciences will buy rockets from an unnamed outside source to launch Cygnus cargo ships, as it speeds up plans to incorporate a better, more powerful engine into its Antares rocket, CEO David Thompson told investors and analysts on a conference call. He did not say which rockets Orbital would buy to fill the gap until the re-engined Antares was ready to fly, but said the options included two U.S. launch providers and one in Europe.
 
The U.S. companies that sell rockets suitable for launching Orbital’s Cygnus capsules include Space Exploration Technology. The privately owned firm, also known as SpaceX, has a separate $1.6 billion contract to fly cargo to the station for NASA. SpaceX declined to comment.