DULLES, Va., April 3 /PRNewswire/ -- Orbital Sciences Corporation (NYSE: ORB) announced today that it will delay the filing with the U.S. Securities and Exchange Commission (SEC) of its Annual Report on Form 10-K for the year ended December 31, 2000. The company expects to file its Annual Report with the SEC no later than April 16, 2001, in accordance with SEC rules and regulations, and will hold a conference call open to interested parties shortly thereafter.

Management is in the process of completing the 2000 year-end financial results which, among other things, is requiring additional time to assess the impact on 2000 results, if any, of NASA's March 1, 2001 termination for convenience of the X-34 reusable launch vehicle contract. In addition, the company is continuing with its efforts towards finalizing two major transactions involving the sale of certain non-core businesses.

Orbital is one of the world's leading manufacturers of low-cost space systems, including satellites, launch vehicles, space sensors and satellite ground systems. Its Magellan subsidiary offers the industry's broadest line of GPS-enabled navigation and positioning products for consumer and industrial markets. Orbital is also involved with satellite-based networks that provide data communications, high-resolution imagery and automotive information services to customers around the world.

More information about Orbital can be found at http://www.orbital.com .

CONTACT: Investors: Timothy Perrott of Orbital Sciences Corporation,
703-406-5997, perrott.tim@orbital.com.

SOURCE Orbital Sciences Corporation

CONTACT: Media: Barron Beneski, 703-406-5528, beneski.barron@orbital.com, or Investors: Timothy Perrott, 703-406-5997, perrott.tim@orbital.com, both for Orbital Sciences Corporation/