DULLES, Va., Jul 15, 2002 /PRNewswire-FirstCall via COMTEX/ --

Geosynchronous Communications Satellite to Provide Millions Of NTT DoCoMo Customers with Mobile Communications Services

Orbital Sciences Corporation (NYSE: ORB) announced today that all systems aboard the Lockheed Martin/Orbital-built N-STAR c geosynchronous orbit (GEO) communications satellite are operating as expected following its successful launch on Friday, July 5, aboard an Ariane 5 rocket from Kourou, French Guiana. Lift-off of the Arianespace S.A. launch vehicle occurred at approximately 7:22 p.m. (EST) and the N-STAR c satellite was deployed into a transfer orbit about a half-hour later. Since the launch, the Orbital lead ground team has successfully maneuvered the satellite into its geosynchronous orbit and has completed early testing and deployment of the solar arrays and antenna. Over the next several weeks, the engineering team will conduct a comprehensive series of in-orbit tests to ensure the spacecraft's final readiness before its hand-over to the customer in August.

The N-STAR c satellite will operate in S-band frequencies with a C-band feeder link from its orbital location at 136 degrees East longitude. The spacecraft is optimized for a 10-year on-orbit life and will provide mobile telephony and data transfer services to Japan and its surrounding waters.

The customer for the N-STAR c satellite is NTT DoCoMo Inc., Japan's premier mobile communications company. NTT DoCoMo provides wireless voice and data communications to tens of millions of subscribers. It is the creator of W-CDMA air interface technology, the new de facto global industry standard for mobile communications, as well as the groundbreaking mobile "i-mode" service.

Commenting on the early results of the mission, Mr. David W. Thompson, Orbital's Chairman and Chief Executive Officer, said, "We are very pleased with the way the N-STAR c mission is progressing. The Ariane launch vehicle accurately delivered the spacecraft into its intended orbit and the satellite is functioning as expected at this stage of its checkout. We are looking forward to delivering an excellent satellite to our NTT DoCoMo customer a little over a month from now."

For the N-STAR c program, Orbital is teamed with Lockheed Martin Commercial Space Systems of Newtown, Pennsylvania. Lockheed Martin is serving as the prime contractor and communications payload supplier. Orbital is responsible for providing the space system, including the satellite bus and related ground system, as well as procuring the launch vehicle and conducting initial satellite operations.

Orbital's GEO communications satellites are based on the company's STAR-1 and STAR-2 standard platforms, which are able to accommodate most types of commercial communications payloads. For many applications, the lighter weight, more affordable STAR design is an attractive alternative to larger, more costly GEO satellites offered by the industry's traditional suppliers. The STAR satellites are smaller and 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 require incremental capacity for their network.

Orbital is one of the world's leading developers and manufacturers of affordable space systems for commercial, civil government and military customers. The company's primary products include low-orbit, geostationary and planetary spacecraft for communications, scientific and remote sensing missions; ground- and air-launched rockets that deliver satellites into orbit; and missile defense boosters that are used as target and interceptor vehicles. Orbital also offers space-related technical services to government agencies and develops and builds satellite-based transportation management systems for public transit and public works agencies, as well as private vehicle fleet operators.

    More information about Orbital can be found at http://www.orbital.com
CONTACT: Barron Beneski, Public and Investor Relations, of Orbital Sciences Corporation, +1-703-406-5528, or Beneski.barron@orbital.com.

                    MAKE YOUR OPINION COUNT -  Click Here
               http://tbutton.prnewswire.com/prn/11690X26191741
SOURCE Orbital Sciences Corporation

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
http://www.prnewswire.com
Copyright (C) 2002 PR Newswire.  All rights reserved.