Orbital Sciences
Corporation (NYSE:ORB) announced today that 2,489,017 (or 54%) of the
4,631,121 common stock purchase warrants issued in 2001 were exercised
prior to their expiration date last week. Each warrant allowed its
holder to purchase one share of the company’s common stock at an
exercise price of $4.82 per share. The company received an aggregate
of approximately $12 million in cash from the exercise of the
warrants, approximately $10 million of which was received during the
third quarter of 2004. As previously announced, the warrants not
exercised on or before August 31, 2004 expired at that time and no
further exercises may be made.

About Orbital

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

Contact:

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