DULLES, Va., Jul 11, 2002 /PRNewswire-FirstCall via COMTEX/ --

Company Continues Strong New Business Performance in Missile Defense Sector

Orbital Sciences Corporation (NYSE: ORB) announced today that it has been awarded a $7.4 million contract by the U.S. Missile Defense Agency (MDA) to fully integrate a new liquid propellant booster that will be used as a target vehicle in future tests of defensive missile systems. Under the contract, Orbital will integrate a government-supplied liquid propellant rocket motor with avionics, guidance and other electrical systems, along with a reentry vehicle, in order to produce an all-new threat-representative target vehicle for MDA. Orbital's Launch Systems Group will carry out the work at the company's facility in Chandler, Arizona.

Mr. Ronald J. Grabe, Orbital's Executive Vice President and General Manager of its Launch Systems Group, said, "We are very pleased to add a liquid fuel target vehicle to the wide array of suborbital launchers used in missile defense applications that we supply to MDA and other U.S. Department of Defense customers. In addition to the liquid propellant-based Upper Stage Flight Experiment that we are currently working on for the Air Force Research Laboratory, this contract positions Orbital as an industry leader in liquid fuel vehicles."

Orbital is one of the country's leading suppliers of ballistic target vehicles and interceptor boosters for missile defense applications. Orbital's target vehicles are used to support such programs as the Ground- and Sea-Based Midcourse Defense systems, as well as the U.S. Army's THAAD, PAC-3, CMP and SRALT programs.

In addition to target vehicles, Orbital is now executing a contract it received earlier this year from The Boeing Company to design, develop, manufacture and test new interceptor boost vehicles for the Ground-Based Midcourse Defense segment of the U.S. missile defense effort.

Orbital is one of the world's leading developers and manufacturers of affordable space systems for commercial, civil government and military customers. The company's primary products include low-orbit, geostationary and planetary spacecraft for communications, scientific and remote sensing missions; ground- and air-launched rockets that deliver satellites into orbit; and missile defense boosters that are used as target and interceptor vehicles. Orbital also offers space-related technical services to government agencies and develops and builds satellite-based transportation management systems for public transit and public works agencies, as well as private vehicle fleet operators.

    More information about Orbital can be found at http://www.orbital.com
CONTACT: Barron Beneski, Public and Investor Relations of Orbital Sciences Corporation, +1-703-406-5528, or Beneski.barron@orbital.com

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SOURCE Orbital Sciences Corporation

CONTACT:          Barron Beneski, Public and Investor Relations of Orbital
                  Sciences Corporation, +1-703-406-5528, or Beneski.barron@orbital.com

URL:              http://www.orbital.com
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