DULLES, Va., Oct 15, 2002 /PRNewswire-FirstCall via COMTEX/ --

Launch Is Company's Sixth Missile Defense Mission of 2002

Orbital Sciences Corporation (NYSE: ORB) successfully launched a target rocket in support of the U.S. Missile Defense Agency's (MDA) Ground-based Midcourse Defense (GMD) system's flight test program, the company announced today. Late yesterday, the company's Orbital/Suborbital Program Target Launch Vehicle (OSP TLV) was launched from Vandenberg Air Force Base, California at approximately 10 p.m. (EDT), which initiated the flight sequence for MDA's Integrated Flight Test-9 (IFT-9). The OSP TLV, which deployed a mock reentry vehicle and decoys, was successfully intercepted over the Pacific Ocean by an exoatmospheric kill vehicle that was carried aboard a booster vehicle launched from the Ronald Reagan Missile Test Site in the Marshall Islands.

"We are once again very proud to support MDA's Integrated Flight Test program with our OSP target vehicle and we congratulate the entire team on the success of the test," said Mr. Ronald J. Grabe, Orbital's Executive Vice President and General Manager of its Launch Systems Group. "Tonight's mission was Orbital's sixth successful target vehicle launch this year in support of various missile defense programs. We also have two more target vehicle launches scheduled to take place before the end of the year. In addition to this year's busy target vehicle schedule, we are progressing right on schedule with the development and test of the new Orbital Boost Vehicle interceptor for the Ground-based Midcourse Defense system," he added.

Orbital is one of the country's leading suppliers of launch vehicles for missile defense applications. The company's target vehicles are used to support numerous Department of Defense programs, including MDA's GMD and Sea- based Midcourse Defense (SMD) programs and the U.S. Army's THAAD, PAC-3, TCMP and SRALT programs. Orbital is also developing a new liquid fuel propulsion system that may be used in the Missile Defense Agency and U.S. Air Force Airborne Laser program.

In addition to target vehicles, Orbital is now designing, manufacturing and testing new interceptor boosters for the GMD system. Over the next two years, Orbital expects to supply approximately 16 to 18 GMD interceptor boosters to the Boeing Company for use in system testing and related operations. Under an optional production phase of the contract, the company could also manufacture and deliver an additional 50 or more boosters through the end of the decade.

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, geosynchronous 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

    For More Information Contact:
    Barron Beneski 703-406-5528
    Public and Investor Relations
    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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