WASHINGTON — Orbital Sciences Corp., under a new agreement with the state of Virginia, formally committed to 10 launches of its yet-unflown Antares rocket from the Mid-Atlantic Regional Spaceport (MARS) on Wallops Island, Va.

Virginia Gov. Robert McDonnell announced the memorandum of understanding, or MOU, in a Sept. 17 press release. The new agreement supersedes many of the provisions of the MOU that Orbital and Virginia signed in 2008 several months after the Dulles, Va.-based company was picked to develop the Antares rocket and Cygnus cargo capsule under NASA’s Commercial Orbital Transportation Services program.

Orbital’s role at the Virginia spaceport, at the southern tip of NASA’s Wallops Island Flight Facility, has been evolving since the 2008 MOU, under which the company agreed to pay for some of the equipment needed to launch Antares from MARS.

Under the old MOU, Orbital was cast as a partner with the state rather than simply a tenant of the spaceport, Orbital spokesman Barron Beneski said in a Sept. 20 phone interview.

Jeffrey Windland, an Orbital vice president and assistant treasurer, even had a voting seat on the Virginia Commercial Spaceflight Authority’s board of directors. The authority runs MARS and oversees construction there. Virginia budget legislation passed in April ordered the authority to remove aerospace companies from that voting role and provided the authority with a bigger budget for capital improvements at the spaceport.

Under the new MOU “we will be simply a user of the spaceport,” Beneski said. The latest MOU “governs the working relationship between Orbital and the Virginia Commercial Spaceflight Authority” and “brings it up to the current realities,” he added.

One reality highlighted prominently in the new agreement is the fact that it will cost much more to prepare Pad 0-A for Antares than either the company or the state anticipated in 2008.

“The launch pad project requirements, costs and schedule escalated beyond the contemplation of the [2008] MOU,” the new document states, without specifying an estimated cost to complete the pad.

Delays certifying Pad 0-A to meet NASA safety standards have pushed back Antares’ maiden launch. Orbital has blamed these delays on the spaceport.

Billie Reed, outgoing executive director of the Virginia Commercial Spaceflight Authority, said the state has invested $36 million in MARS since 2008 through a combination of bond issues and a Virginia Transportation Department grant. Beneski would not say how much money Orbital has put into MARS, but the Aug. 10 MOU said the company “has made a capital investment of at least $45 million” in Virginia in connection with the Antares project. In addition to its Wallops presence, Orbital builds elements of the Antares system at its main campus in Dulles, Va.

In another reflection of Orbital’s transition from partner to spaceport user, the Virginia Commercial Spaceflight Authority agreed to purchase some $26 million worth of fluid transfer and handling assets whose construction and integration at MARS was paid for by Orbital.

The state intends to limit the purchases to equipment not specifically designed for the Antares rocket. However, there are $16.5 million worth of Orbital-funded assets at MARS whose categorization the state and the company do not agree upon, according to the new MOU. Among these is the horizontal transport vehicle used to roll Antares out to Pad 0-A.

The Virginia Commercial Spaceport Authority and Orbital planned to hire the Aerospace Corp. of El Segundo, Calif., to decide which of the disputed assets are specific to Antares and which are not. If the Aerospace Corp. decides that a piece of hardware could be adapted “without significant modification” for use with other rockets, the state would buy that hardware, according to the MOU. The Aerospace Corp. must classify the equipment by Sept. 16.

Orbital has a $1.9 billion NASA contract to make eight cargo flights to the international space station. Before it can collect on that contract, the company has to perform two demonstration flights of its Antares rocket.

Under the new MOU, Orbital will pay the state $1.5 million per launch for each of these 10 NASA missions. If Orbital wants to launch any other Antares missions from Pad 0-A, fees would start at $1 million per launch.

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.