DULLES, Va.Sept. 8, 2004--Orbital Sciences Corporation (NYSE:ORB) announced today that its Vice Chairman and Chief Financial Officer Garrett E. Pierce will make a presentation to investors and analysts during Sidoti & Company's Third Annual West Coast Emerging Growth Institutional Investor Forum to be held in San Francisco, California at the Ritz-Carlton San Francisco. Orbital's presentation is scheduled to take place at 11:35 a.m. (PDT) on Tuesday, September 14.

Orbital will make available the slides that Mr. Pierce will present to the live audience on the company's web site at: http://www.orbital.com/Investor/. The slides will be posted prior to the beginning of the live presentation.

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
             Public and Investor Relations:
             Barron Beneski, 703-406-5528
             Beneski.barron@orbital.com

    SOURCE: Orbital Sciences Corporation