PARIS — Orbital Sciences Corp.’s contract with startup Stratolaunch Systems on a rocket to be launched from beneath a large aircraft will produce an enhanced version of Orbital’s Antares rocket capable of handling 15-25 percent more payload, depending on the orbit, Orbital Chief Executive David W. Thompson said April 23.

Addressing a meeting of Dulles, Va.-based Orbital’s shareholders, Thompson said Stratolaunch, backed by Microsoft co-founder Paul Allen’s Vulcan Capital, “is one of our most exciting programs” and will lead to an operational vehicle in three or four years.

The air-launched version of Orbital’s existing Antares vehicle, which debuted in early 2013 and is now focused on sending cargo to the international space station under a NASA contract, will be able to carry between 7,000 and 8,000 kilograms of payload into low Earth orbit.

Given the competitive market for heavier-lift rockets, Thompson said, there is no need for Orbital to continue to add muscle to Antares beyond the Stratolaunch-enhanced performance. The market for launch services carrying 10,000 to 20,000 kilograms into low Earth orbit “is sufficiently served by other operators,” he said.

The relationship with Huntsville, Ala.-based Stratolaunch will require no investment in research and development by Orbital, he said.

The Antares rocket now operated by Orbital has made two cargo deliveries to the space station and is scheduled to conduct a third in June. Frank L. Culbertson, manager of Orbital’s advanced programs group, told shareholders that three cargo missions in eight months compares favorably with Space Exploration Technologies Corp., which is operating under a similar cargo-delivery contract with NASA.

“That other company, by the way, launched last week and made it to the space station,” said Culbertson, who like Thompson did not mention SpaceX by name. “It was their first flight in 18 months. But, you know, who’s counting.”

Thompson said the current NASA station resupply contract and a likely extension, followed by a new contract this year or next, should result in Orbital’s launching Antares and the Cygnus pressurized cargo module on “two or three missions a year for at least the next decade” given NASA’s intention to operate the station at least until 2024.

A steady rate of Antares-Cygnus launches is one reason Orbital is predicting a huge increase in annual free cash flow starting this year and continuing through 2016. With Antares and Cygnus research and development spending completed, the cargo supply program is transitioning from a cash consumer to a cash producer.

Asked whether tensions with Russia about its relations with Ukraine could disrupt the Antares program, which uses Russian engines for its first stage and a Ukrainian first-stage airframe, Thompson said he had no real concerns about supply-chain stability.

The United States and Russia have maintained steady cooperation in space for nearly 40 years, through multiple diplomatic ups and downs, he said. “I expect that’s likely to be the case now as well,” Thompson said.

But as a precaution, he said Orbital is considering an all-U.S.-built Antares first stage, for both the engine and the airframe, as it weighs a long-term contract. Thompson told investors on April 17 that Orbital is weighing offers from three companies for the Antares first-stage engine. Two are from Russia, including the current supplier, and one is from the United States.


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Peter B. de Selding was the Paris Bureau Chief for SpaceNews.