DULLES, Va., Oct. 17 /PRNewswire/ -- With another successful rocket launch, Orbital Sciences Corporation (NYSE: ORB) continued to build on the outstanding record of reliability that its family of space and suborbital launch vehicles has compiled over the past 18 years. The latest successful mission for an Orbital-built rocket occurred on Saturday, October 14 at White Sands Missile Range in New Mexico with the launch of a suborbital target vehicle for the U.S. Army's Maneuverable 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.

The successful MTTV mission brings Orbital's overall launch vehicle mission success record to 135 out of 142 total launches. These include 34 successes out of a total of 37 missions conducted by the company's Pegasus, Taurus and Minotaur space launch vehicles, as well as 101 successes out of 105 total suborbital launches carried out by Orbital's wide variety of rocket configurations.

For the MTTV mission, 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 reentry vehicle.

Orbital is one of the largest space technology and satellite services companies in the world, with 1999 total enterprise revenues (including revenues from unconsolidated affiliates) of approximately $915 million. The company, headquartered in Dulles, Virginia, employs about 5,000 people at major facilities in the U.S., Canada and several overseas locations. Orbital is the world's leading manufacturer of low-cost space systems, including satellites and space robotics, launch vehicles, electronics and sensors, satellite ground systems and related digital infrastructure. Its Magellan subsidiary is a pioneer in satellite-based navigation and communications products for consumer and industrial markets. Through its ORBCOMM and ORBIMAGE affiliates and ORBNAV subsidiary, Orbital is also a major operator of satellite-based networks that provide data communications, high-resolution imagery and automotive information services to customers around the world. SOURCE Orbital Sciences Corporation

/NOTE TO EDITORS: To learn more about Orbital and our family of space and suborbital launch vehicles, as well as to access our recent press releases, please visit our web site at http://www.orbital.com/

CONTACT: Barron Beneski of Orbital Sciences Corporation, 703-406-5000 or Beneski.barron@orbital.com/