DULLES, Va., Dec. 29 Orbital Sciences Corporation’s advanced space technologies played important roles in the
successful completion of repairs to NASA’s Hubble Space Telescope recently carried out by the crew of Space Shuttle flight STS-103, according to the
company. Orbital’s Remote Manipulator System (RMS), also know as the “Canadarm” and built by the company’s MDRobotics Division in Brampton,
Ontario, Canada, was used to capture, berth and release the space-based observatory after the Shuttle’s rendezvous with it, and was also employed as the
platform to maneuver and position the astronauts performing “spacewalk” repair work on the telescope. In addition to the RMS, Orbital also provided
custom-designed equipment (supplied by the Technical Services Division of the company’s Space Systems Group), in which the six new gyroscopes, which
were installed in the Hubble telescope by the astronauts, were carried into orbit by the Shuttle.

“Orbital continues to build its range of technologies and base of experience in the nation’s manned space flight program,” said Mr. J.R. Thompson,
Orbital’s President and Chief Operating Officer. “While Orbital is known around the world as the leading supplier of highly-reliable small- and
medium-class space systems, such as lightweight satellites, launch vehicles and space sensors, we have also developed and assembled a stable of products
and services that play important roles in current NASA Space Shuttle activities. Looking to the future, these and other technologies will also assist with the
construction and continuing operation of the International Space Station. From a business perspective, these technologies bring us opportunities to grow into
areas of the space industry that have been traditionally outside our core markets,” he said.

The Space Shuttle mission to the Hubble telescope capped a year of significant operational successes for Orbital’s space systems in 1999. During the year,
the company carried out a total of 19 space missions, all of which were successful. Among the year’s highlights were these accomplishments:

  • Orbital delivered and launched 11 satellites for commercial and government customers, all of which are operating successfully. Orbital’s Space Systems
    Group, the company’s satellite manufacturing unit, was also certified as being compliant with ISO-9001 standards, the world’s most widely-recognized
    quality- assurance system for design and manufacturing processes.

  • The company carried out five successful launch vehicle missions, continuing Orbital’s 100% success rate in 27 rocket launches during the past three
    years. This year’s launches included three Pegasus® and one Taurus® rocket launches which boosted a total of 12 satellites into orbit. The Pegasus
    rocket has now successfully completed 14 consecutive missions, while Taurus is a perfect four-for-four in its operational history.

  • Orbital completed the first of three X-34 reusable launch vehicles and conducted the initial series of flight testing at NASA’s Dryden Flight Research
    Center in California.

  • The company supported three major space payload operations on several Space Shuttle missions, including two that used Orbital’s RMS technology
    in flawless in-orbit operations.

With these 1999 missions, Orbital’s overall space mission record was extended to 292 satellite deployments, rocket launches and space payload operations
during the last 18 years. In the last three years alone, the company has conducted a total of 81 space missions, involving 43 satellite deployments, 27 rocket
launches and 11 space payload operations.

Orbital is one of the largest space technology and satellite services companies in the world, with 1999 revenues targeted to exceed $900 million. The
company, which is headquartered in Dulles, Virginia, employs over 5,200 people at its major facilities in the United States, Canada and several overseas
locations. Orbital is the world’s leading manufacturer of low-cost space systems and products, including satellites, launch vehicles, electronics and sensors,
satellite ground systems and software, and satellite-based navigation and communications products. Through its ORBCOMM and ORBIMAGE affiliates and
ORBNAV subsidiary, Orbital is also a pioneering operator of satellite-based networks that provide data communications, high-resolution imagery and
automotive information services to customers all around the world.