Company to Be Responsible for the Design, Production and Flight of Boost Vehicle to Verify Astronaut Safety System

Initial Three-Year Contract from U.S. Air Force Space and Missile Systems Center, Space Development and Test Wing Valued at Approximately $35 Million; Contract Also Includes $45 Million of Options for Additional Test Flights and Spare Vehicles

Orbital Sciences Corporation (NYSE:ORB) today announced that it has been selected by the National Aeronautics and Space Administration (NASA) and the U.S. Air Force Space Development and Test Wing (SDTW) to design and build the next-generation NASA Orion Abort Test Booster (ATB). The contract was awarded under SDTW’s Sounding Rockets Program 2 (SRP-2) contract, which allows the use of surplus government boosters to reduce launch vehicle cost for U.S. Government-sponsored missions.

The ATB is part of NASA’s Orion Crew Exploration Vehicle project 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 role is to develop, build and test a new booster configuration to demonstrate and qualify the Orion Launch Abort System (LAS) that will allow the astronaut crew to safely escape in the event of an emergency during launch pad operations and through the ascent of the Orion vehicle. As part of the Lockheed Martin Corporation-led team, Orbital is also designing and building the LAS. Previous abort test boosters for the Mercury and Apollo programs have been called Little Joe I and Little Joe II, respectively. The ATB design, using Orbital’s proven rocket technology, is a key element in demonstrating the new system that will vastly improve the safety of the flight crew.

“We are very pleased to be a member of the NASA/SDTW Orion ATB team, particularly for these early Orion flights, which will demonstrate important crew safety systems,” said Mr. Mark Ogren, Orbital’s Vice President of Business Development of its Launch Systems Group. “Orbital had been working toward designing the optimal vehicle configuration that will best perform these missions for over three years.”

Orbital is under contract to the Air Force to manage, design, build and test the ATB at its Chandler, Arizona campus, as well as at government test facilities in California and New Mexico. The basic contract calls for a three-year program, including developmental activities and two planned flights in 2009 and 2010. Contract options could add up to two additional flights and two spare vehicles through 2011.

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