Orbital Sciences
Corporation announced today that it has commenced a cash tender
offer and consent solicitation (the “Offer”) for any and all of its $135
million outstanding principal amount of 12% Second Priority Secured Notes due
12:00 midnight (EDT), on Friday, July
18, 2003, unless extended or earlier terminated (the “Expiration Date”).
Holders of the Notes who tender their Notes and deliver consents on or prior
to 5:00 p.m., (EDT), on Tuesday, July 1, 2003 (the “Consent Date”), will
receive 105.025% of the principal amount of the Notes validly tendered.
Holders who tender their Notes after the Consent Date but prior to the
Expiration Date will receive 104% of the principal amount of the Notes validly
tendered. In each case, holders who validly tender their Notes shall receive
accrued and unpaid interest and liquidated damages on such principal amount of
Notes up to, but not including, the applicable payment date.

The Offer is subject to the satisfaction of certain conditions, including
the Company’s receipt of valid tenders from holders of at least a majority of
the outstanding principal amount of the Notes and debt financing sufficient to
consummate the Offer on terms acceptable to the Company.

The complete terms and conditions of the Offer are described in the
Company’s Offer to Purchase and Consent Solicitation Statement dated June 20,
2003 (the “Offer Statement”), copies of which may be obtained by contacting
the information agent, D.F. King & Co., Inc. at (888) 567-1626.

The Company has engaged Banc of America Securities LLC to act as exclusive
dealer manager and solicitation agent in connection with the Offer. Questions
regarding the Offer may be directed to Banc of America Securities, High Yield
Special Products, at (888) 292-0070 or (704) 388-4807 (collect). Requests for
documentation may be directed to the D.F. King & Co., Inc. information agent
for the Offer, at (888) 567-1626. The depositary for the Offer is U.S. Bank
National Association.

The Offer is made solely by the Offer Statement. This press release does
not constitute an offer to purchase (or a solicitation of an offer to sell)
the Notes.

Orbital develops and manufactures small space and missile systems for
commercial, civil government and military customers. The Company’s primary
products are satellites 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

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, beneski.barron@orbital.com; or Jonah
Hirsch of Banc of America Securities LLC, +1-704-388-4807,