Orbital Sciences Corporation has completed its merger with Ashtech, Inc. of Sunnyvale, CA with its Magellan Corporation subsidiary. The merger became final on December 31, 1997, after Orbital received all necessary regulatory clearances and approval of the transaction by Ashtech shareholders. Under the terms of the merger that were previously announced, Orbital now owns approximately 66% of the combined company, which will continue to operate as Magellan, after providing Ashtech security holders with $25 million in cash. The former Ashtech security holders own the remaining 34% of the new company.

As a result of the merger, Magellan now offers the broadest line of
products that utilize Global Positioning System (GPS) satellite technology to
provide navigation and positioning information for consumer, automotive and
professional markets. Magellan is also a leading maker of satellite-based
messaging and voice communications products, including hand-held mobile e-mail messaging units and portable satellite telephones.

Mr. David W. Thompson, Orbital’s President and Chief Executive Officer,
said, “In 1997, through the Ashtech merger and the acquisition of the
PathMaster car navigation system, we positioned Magellan to be the world’s
leading company in the development, manufacture and sales of a variety of
products that use satellite technology for rapidly expanding global markets in navigation, positioning and communications applications.”

Magellan is now headed by Mr. Charles M. Boesenberg, Ashtech’s former
President and Chief Executive Officer, who assumes the same positions at
Magellan. Mr. Boesenberg also will become an Executive Vice President of
Orbital. The combined company employs over 500 people at its Sunnyvale, CA
headquarters and at major product centers in San Dimas, CA; Rochester Hills,
MI; and Moscow, Russia. Its products will be available at over 12,000 retail
locations in the United States and through more than 150 distributors in 90
countries. It will maintain manufacturing operations in California and
Taiwan.

In the consumer market, Magellan is an industry leader and product
innovator in hand-held GPS navigators and other low-cost satellite access
products that are making satellite networks increasingly available to users
around the world. Magellan’s products are used in outdoor recreation
activities, such as hiking, camping, hunting and fishing, and in boating,
general aviation and related consumer applications. Magellan is also the
United States market leader in high-performance automotive navigation systems,
developed by the company’s Driver Information Systems unit, which provide
turn-by-turn directions and electronic map route guidance to individual
motorists.

With the addition of Ashtech’s product lines, Magellan is also now an
industry pacesetter in the development and manufacture of high-performance GPS
and related satellite navigation products, components and technologies. These
products cover professional, OEM and other high-precision industrial
applications, such as guiding aircraft to low-visibility landings, surveying
for construction projects, guiding equipment in farming and mining operations,
broadcasting “differential GPS” correction signals for the U.S. Coast Guard
and monitoring of Earth’s surface movements for geodetic researchers.

As a satellite navigation technology leader, Ashtech has developed
proprietary techniques that substantially increase positioning accuracy,
reduce errors from signal distortion and decrease the time required to
calculate an initial position. In addition, Ashtech pioneered GPS+GLONASS
(Russian satellite navigation system) technology and possesses significant
capabilities in application-specific integrated circuit (ASIC) and software
development.

Orbital is a space and information systems company that designs,
manufactures, operates and markets a broad range of affordable space
infrastructure systems, satellite access products and satellite-provided
services including launch vehicles, satellites, sensors and electronics,
satellite ground systems and software, satellite-based navigation and
communications products, and satellite-delivered fixed and mobile
communications and Earth imaging services.