Orbital Sciences Corporation
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 .

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