For Immediate Release
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Barron Beneski (703) 406-5528
Public and Investor Relations


-- First Step Taken Toward Broadening Antares Launch Contracts Beyond Cargo Resupply Missions to International Space Station --

(Dulles, VA 27 June 2012) -- Orbital Sciences Corporation (NYSE: ORB) today announced that it has successfully completed contract negotiations with the National Aeronautics and Space Administration (NASA) to "on-ramp" its Antares(TM) medium-class launch vehicle onto the NASA Launch Services-II (NLS-II) program. The NLS program is a contracting mechanism that allows NASA to procure qualified launch vehicles that have completed stringent technical and pricing reviews. The Antares rocket joins other Orbital launch vehicles, as well as those from other launch services providers, on the NLS program. Under the NLS program and other contracts, Orbital rockets have carried out 27 successful missions for NASA since 1996, including the recent successful launch of Orbital's small-class Pegasus rocket, which carried the company-built Nuclear Spectroscopic Telescope Array (NuSTAR) satellite into orbit earlier this month.

"The on-ramping of the Antares rocket to the NLS program is an important step in broadening the launch manifest beyond the cargo logistics missions to the ISS," said Mr. Ron Grabe, Orbital's Executive Vice President and General Manager of its Launch Systems Group. "The NLS program has served as an effective way for NASA to procure the appropriately sized and priced launch vehicles, which have had mutual benefits to NASA and Orbital. We anticipate providing reliable and affordable launch services to NASA with America's newest medium-class launch vehicle."

Orbital is finalizing the development and ground testing of the Antares rocket and is scheduled to conduct two launches before the end of the year under the Commercial Orbital Transportation Services (COTS) demonstration program with NASA. In addition, Orbital will launch eight operational cargo resupply missions to the International Space Station (ISS) using Antares vehicles through 2016 under NASA's Commercial Resupply Services (CRS) contract. The COTS and CRS flights will launch from NASA's Wallops Flight Facility in eastern Virginia, which is ideally suited for ISS missions, and can also accommodate launches to other mission orbits. In addition, Orbital is currently evaluating its options for development of a west coast launch site that would enable the Antares rocket to address an even wider range of customer missions.

The Antares medium-class launch system will provide a significant increase in the payload launch capability that Orbital can provide to NASA for its missions. The Antares rocket will be able to launch up to 13,000 lbs. into low-Earth orbit, as well as lighter-weight payloads into higher-energy orbits. Orbital's newest launcher is a cost-effective alternative to the medium- and intermediate-class launch vehicles currently on the NLS-II program, and is "right- sized" for many of NASA scientific payloads, which have traditionally flown on other medium lift launch vehicles.

About Orbital

Orbital develops and manufactures small- and medium-class rockets and space systems for commercial, military and civil government customers. The company's primary products are satellites and launch vehicles, including low-Earth orbit, geosynchronous-Earth orbit and planetary spacecraft for communications, remote sensing, scientific and defense missions; human-rated space systems for Earth-orbit, lunar and other missions; ground- and air-launched rockets that deliver satellites into orbit; and missile defense systems that are used as interceptor and target vehicles. Orbital also provides satellite subsystems and space-related technical services to government agencies and laboratories. More information about Orbital can be found at

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