Orbital Sciences Corporation announced today that it
will release its fourth quarter and year-end 2003 financial results
prior to the opening of the market on Thursday, February 12, 2004.
Orbital will also conduct a conference call with financial analysts
and investors the same morning, beginning at 9:00 a.m. (EST). The
conference call will be hosted by:

  • Mr. David W. Thompson, Chairman and Chief Executive Officer
  • Mr. Garrett E. Pierce, Vice Chairman and Chief Financial
    Officer
  • Mr. James R. Thompson, Vice Chairman and Chief Operating
    Officer

To listen to the conference call, dial (888) 541-8767, and use the
conference ID number 5402243. A replay of the conference call will be
available approximately two hours after the end of the call and will
remain active for one week, until Thursday, February 19, 2003. For
access to the replay of the conference call, dial (800) 642-1687
(international callers should dial (706) 645-9291) and use the same
conference ID number.

For webcast registration and information, please visit Orbital’s
web site at http://www.orbital.com/Investor. It is advisable to
register at least 20 minutes prior to the call to download and install
any necessary audio software.

Orbital is one of the world’s leading developers and manufacturers
of small space systems for commercial, civil government and military
customers. The company’s primary products are spacecraft and launch
vehicles, including low-orbit, geostationary and planetary spacecraft
for communications, remote sensing and scientific missions; ground-
and air-launched rockets that deliver satellites into orbit; and
missile defense boosters 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.

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

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