DULLES, Va., Nov 18, 2004 (BUSINESS WIRE) -- Orbital Sciences Corporation (NYSE:ORB) announced today that it recently carried out another successful launch of a missile defense-related target rocket for the U.S. Missile Defense Agency (MDA). The latest success for an Orbital-built missile occurred on Thursday, November 18 at the White Sands Missile Range in New Mexico. Orbital launched this suborbital target vehicle for the Missile Defense Agency's Maneuvering Tactical Target Vehicle (MTTV) program. The MTTV rocket, which performed its mission as planned, was used as a target to test the Patriot missile defense system.

"It has been an extraordinarily busy and successful two-week period for our launch teams, culminating with the successful MTTV launch for the Missile Defense Agency," said Mr. Ron Grabe, Executive Vice President and General Manager of the Company's Launch Systems Group. "We are very proud of our record of supporting MDA's flight test programs with the most reliable target vehicles in the industry. We look forward to our future missions that will help MDA develop, test and deploy effective missile defense systems."

Orbital provided and tested the rocket's guidance and separation systems, performed all vehicle design, production and integration activities and conducted all launch day mission operations. The MTTV rocket is a single stage vehicle which uses a retired U.S. government rocket engine from the Minuteman ICBM program and a modified Pershing II reentry vehicle.

About Orbital

Orbital develops and manufactures small space systems for military, commercial and civil government customers. The company's primary products are launch vehicles and satellites, including missile defense boosters that are used as interceptor and target vehicles, ground- and air-launched rockets that deliver satellites into orbit, and low-orbit, geostationary and planetary spacecraft for communications, remote sensing and scientific missions. 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

SOURCE: Orbital Sciences Corporation

Orbital Sciences Corporation
Barron Beneski, 703-406-5528
Beneski.barron@orbital.com