SAN DIEGO — Orbital Sciences Corp. expects to have U.S. government approval within about a year for using its Antares rocket to launch payloads to sun-synchronous orbit from NASA’s Wallops Flight Facility on Virginia’s eastern shore, a company executive said Aug. 5.

“We’ve been working with NASA, the [Federal Aviation Administration] and other agencies to get approval to fly high-inclination missions from the Wallops site,” John Steinmeyer, a senior program manager at Orbital, said in an interview here at the American Institute of Aeronautics and Astronautics’ Space 2014 conference.

The earliest possible date for such a mission is still “a year or so out,” Steinmeyer said. Orbital has not identified any candidate payloads for a sun-synchronous launch.

“Orbital has expressed an interest to NASA Wallops in flying southward to a higher-inclination/sun-synchronous orbit, though no specific mission or date has been proposed to the range,” NASA spokesman Jeremy Eggers wrote in an Aug. 7 email. “As far as what Orbital would need to do to fly this trajectory, that would depend on the details of the mission.”

Currently Antares is used to launch cargo resupply missions to the international space station, whose orbital inclination — the angle at which it passes over the equator — of 51.6 degrees dictates that the rocket follow a southeasterly flight path over the Atlantic Ocean. To reach high-inclination orbits, the vehicle would presumably need to fly more directly toward the equator.

Among the details to be settled is the exact configuration of the Antares rocket Orbital would use to place satellites into sun-synchronous orbits, which are commonly used for Earth observation missions. The Antares rockets flown to date have been two-stage vehicles, but the company offers three-stage versions for missions with more stringent orbital-insertion accuracy or high-energy requirements.

Orbital is preparing to swap the ATK-built Castor 30B solid-fueled second stage used on Antares’ last flight from Wallops’ Mid-Atlantic Regional Spaceport for ATK’s more powerful Castor 30XL. The change will allow Antares, which uses a liquid-fueled core stage, to boost about 1,000 more kilograms to low Earth orbit, Steinmeyer said.

Antares has flown to the space station three times since a demonstration launch in April 2013. Orbital is expected to fly another six cargo missions to the space station under a $1.8 billion  services contract with NASA.

David Thompson, Orbital’s chief executive, said the company has submitted Antares launch bids to at least two unidentified commercial customers.

Dan Leone is a SpaceNews staff writer, covering NASA, NOAA and a growing number of entrepreneurial space companies. He earned a bachelor’s degree in public communications from the American University in Washington.