-- First of Three GEO Communications Spacecraft for PanAmSat in Final Preparations for March Launch Aboard Ariane Rocket --

Over the next several weeks, a team of engineers from PanAmSat, Arianespace and Orbital will work together to integrate the satellite with the launch vehicle and perform an extensive series of tests to ensure that the combined systems of the satellite and rocket are working properly.

"We are very excited to be in the final stages of completing and delivering the first of three satellites for PanAmSat, one of the world's premier satellite services companies," said Dr. Ali Atia, head of Orbital's communications satellite division. "We expect 2003 to be a very busy year for our GEO satellite manufacturing operations. We are scheduled to complete and deliver two other GEO spacecraft, including the second satellite for PanAmSat in late 2003."

In the past several years, Orbital has developed a strong niche position in the world market for GEO communications satellites. With its ramp-up in the production of small, lighter-weight satellites, the company is on track to replicate its decade-long success of its small-sized Pegasus(R) and Taurus(R) rockets that were introduced to the world launch vehicle market in the early 1990s.

Orbital's GEO satellites are based on the company's STAR family of smaller GEO satellite platforms, which are able to accommodate most types of commercial communications payloads. For many applications, the STAR design is an attractive alternative to the larger, more costly GEO satellites offered by the industry's traditional suppliers. The STAR satellites are smaller and are significantly less expensive to manufacture and launch. They are a perfect fit for customers in the early stages of building their business or established companies that wish to replace or add capacity to their network.

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

A high-resolution image of PanAmSat's Galaxy XII satellite is available on Orbital's web site at: http://www.orbital.com/NewsInfo/Images/GEO/index.html

    For More Information Contact:
    Barron Beneski (703) 406-5528
    Public and Investor Relations
    Beneski.barron@orbital.com

CONTACT:          Barron Beneski, Public and Investor Relations, of Orbital
                  Sciences Corporation, +1-703-406-5528, or Beneski.barron@orbital.com

URL:              http://www.orbital.com
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