Company to be Responsible for the Design, Production and Testing of Launch Abort System to Vastly Improve Astronaut Crew Safety

Initial Five-Year Subcontract from Lockheed Martin Valued at Approximately $250 Million

Orbital Sciences Corporation (NYSE: ORB) today announced that it will play a significant role on the Lockheed Martin Corporation (NYSE: LMT)-led team that was selected yesterday by the National Aeronautics and Space Administration (NASA) to design and build the next-generation human space exploration system called Orion.

NASA’s Orion project is an advanced crew capsule design utilizing state-of-the-art technology that will succeed the Space Shuttle in transporting humans to and from the International Space Station, the Moon and, eventually, to Mars and beyond. Orbital’s principal role on the Lockheed Martin team is to design, develop, build and test a new Launch Abort System (LAS) that would allow the astronaut crew to safely escape in the event of an emergency during launch pad operations and through the atmospheric ascent of the Orion vehicle into Earth orbit. The company will also perform system-level safety and reliability analyses in support of the entire project. The LAS design, using Orbital’s proven small rocket technology, is a key element in vastly improving the safety of the flight crew as compared to current human space systems.

“We are very pleased to be a member of the NASA/Lockheed Martin Orion team, particularly in a critical area that will significantly improve the safety of the flight crew,” said Dr. Antonio L. Elias, Orbital’s Executive Vice President and General Manager of its Advanced Programs Group. “With this selection, we have realized a strategic goal of the company to participate in America’s reenergized human spaceflight program, building on our experience in carrying out numerous robotic space missions for NASA and other customers over the past two decades,” Elias added.

Orbital will manage, design, build and test the Orion-related LAS at its Dulles, VA campus, at the facilities of its propulsion subcontractors, Aerojet Systems, a unit of GenCorp, Inc. (NYSE: GY), and Alliant Techsystems, Inc. (NYSE: ATK), and at government test facilities in Florida and New Mexico. The contract calls for a five-year development program, including several planned abort demonstration flights and culminating in initial crewed flights to orbit in the 2012 to 2014 timeframe. This is expected to be followed by a series of operational missions to the International Space Station and the Moon in the post-2014 period.

About Orbital

Orbital develops and manufactures small space and rocket systems for commercial, military and civil government customers. The company’s primary products are satellites and launch vehicles, including low-orbit, geosynchronous-orbit and planetary spacecraft for communications, remote sensing, scientific and defense 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 offers space-related technical services to government agencies and develops and builds satellite-based transportation management systems for public transit agencies and private vehicle fleet operators. More information about Orbital can be found at http://www.orbital.com