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                                                                    EXHIBIT 23.1

                              ACCOUNTANTS' CONSENT

THE BOARD OF DIRECTORS
ORBITAL SCIENCES CORPORATION AND SUBSIDIARIES:

      We consent to the incorporation by reference in the registration
statements on Forms S-8 (Nos. 33-84296, 33-62277, 33-64517, 333-53585,
333-69887, 333-69885, and 333-27999) of Orbital Sciences Corporation and
subsidiaries of our reports dated February 5, 1997, except as to note 1A, which
is as of April 17, 2000, relating to the consolidated balance sheets of Orbital
Sciences Corporation as of December 31, 1996 and 1995, and the related
consolidated statements of operations, stockholders' equity, cash flows and the
related financial statement schedule for each of the years in the three-year
period ended December 31, 1996, which reports appear in the December 31, 1996
annual report on Form 10-K/A of Orbital Sciences Corporation.

         Our reports refer to the restatement of the consolidated balance sheets
as of December 31, 1996 and 1995, and the consolidated statements of operations,
stockholders' equity and cash flows, and the related consolidated financial
statement schedule, for each of the years in the two-year period ended December
31, 1996.

                                    KPMG LLP

WASHINGTON, D.C.
JUNE 26, 2000