DULLES, Va.March 23, 2004--

Newly Created Position to Support Orbital's Military Space Market Initiatives

Orbital Sciences Corporation (NYSE:ORB) today announced that Mr. David A. Anhalt has joined the company as Senior Director of Special Programs in its Advanced Programs Group. In his position, Mr. Anhalt will lead Orbital's efforts in providing innovative space systems for the national security and military space market. Mr. Anhalt joins Orbital after a distinguished 28-year career in the United States Air Force, during which he attained the rank of Colonel and served in senior roles on numerous aircraft and space programs.

"I am delighted to welcome Dave to our team," said Dr. Antonio L. Elias, Orbital's Executive Vice President and General Manager of its Advanced Programs Group. "His broad experience will be of tremendous benefit to the company as we apply our innovative thinking to provide responsive, more affordable space systems to the defense and intelligence communities."

Prior to joining Orbital, Mr. Anhalt served in both the Department of Defense and on the Air Staff at the Pentagon. Most recently, he served as Chief of the Space Control and Advanced Technologies Division for the Undersecretary of the Air Force. In that role, he directed the development and procurement of defensive and offensive counterspace systems, as well as new satellite capabilities to enhance U.S. military advantage. Mr. Anhalt also served as the Air Force Military Assistant to the Director of Net Assessment, Office of the Secretary of Defense, where he directed comparative analyses of U.S. and foreign use of long-range strike and space systems in warfare. Earlier in his military career, he led the production team for the Joint Surveillance Target Attack Radar System (JSTARS) aircraft manufacturing program. Mr. Anhalt is also a graduate of the U.S. Air Force Test Pilot School.

Mr. Anhalt received a B.S. degree in Electrical Engineering from the U.S. Air Force Academy. He also holds a M.S. degree in Aerospace and Mechanical Sciences from Princeton University and a M.A. degree in International Relations from Queen's University, Ontario, Canada.

About Orbital's Advanced Programs Group

Orbital's Advanced Programs Group pursues new business opportunities in three primary markets, advanced flight systems for NASA and other civil and military customers, advanced tactical systems and advanced space systems for defense and intelligence customers.

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.

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

Note to editors: A high-resolution (300 dpi) photo of Mr. Anhalt is available for publication. Please request an electronic copy of the photo at public.relations@orbital.com.

    CONTACT: Orbital Sciences Corporation
             Barron Beneski, 703-406-5528

    SOURCE: Orbital Sciences Corporation