— Consistent with Company’s Financial Improvement Plan, Orbital Has
Reduced Debt by Approximately $200 Million in 2001 —

Orbital Sciences Corporation (NYSE: ORB)
today that it has completed the sale of its Magellan Corporation subsidiary
its 60% interest in Navigation Solutions LLC (NavSol), a joint venture with
Hertz Corporation, to Thales Group for approximately $70 million in cash.
Orbital originally announced the proposed sale in May and has received all
required regulatory approvals for the transaction. The completion of the
Magellan/NavSol sale advances Orbital’s strategy to focus on its core space
technology products and to strengthen its balance sheet through significant

Mr. David W. Thompson, Orbital’s Chairman and Chief Executive Officer, said,
“With the proceeds from the sale of Magellan/NavSol, combined with the
from the sale of our MacDonald, Dettwiler and Associates subsidiary, Orbital
significantly improved its financial position. Since the beginning of 2001,
have reduced our total debt balance by approximately $200 million, placing
company in a greatly improved position from the standpoint of liquidity and
financial flexibility.”

About Magellan

Magellan is one of the world’s leading manufacturers global positioning
(GPS) products used by outdoor recreation, marine and automotive consumers
navigation purposes and by professional customers for highly-accurate
and mapping applications. Based in Santa Clara, CA, Magellan employs
approximately 370 people at major facilities in California’s Silicon Valley
Los Angeles areas, as well as in several other states and international
locations. NavSol is based in Plano, TX and employs approximately 75
primarily in Texas and Michigan.

About Thales Group

Thales is a European leader and global front-runner in professional
in three key markets: Aerospace, Defense and Information Technology &
The Group employs 65,000 people worldwide, of whom 50% are based outside of
France. Present in nearly 50 countries, Thales generated revenues of 8.6
billion Euros in 2000 ($7.9 billion*), 70% of which came from international
sales. (* Average exchange rate for 2000: 1 Euro = US$ 0.9175)

About Orbital

Orbital develops and manufactures affordable space systems, including
satellites, launch vehicles, sensors and electronics, and advanced systems.
Orbital is also involved with satellite-based networks that provide wireless
data communications and high-resolution Earth imagery to customers all
the world.

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