8-K

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                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549


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                                    FORM 8-K

                                 CURRENT REPORT


                        Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934


     Date of Report (Date of earliest event reported):  September 11, 1997

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                          ORBITAL SCIENCES CORPORATION


       DELAWARE                    0-18287                     06-1209561
(State of incorporation)   (Commission File Number)   (I.R.S. Employer I.D. No.)
                          

                            21700 ATLANTIC BOULEVARD
                             DULLES, VIRGINIA 20166
                                 (703) 406-5000
                         (Address and telephone number
                        of principal executive offices)





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ITEM 5.  OTHER EVENTS

         On September 11, 1997, Orbital Sciences Corporation announced in a
press release attached as Exhibit 99 to this Form 8-K that it will sell $90
million in 5% convertible subordinated notes due October 2002 within the United
States pursuant to Rule 144A of the U.S. Securities Act of 1933, as amended,
and outside the United States pursuant to Regulation S under that Act.  The
offering is expected to close September 16, 1997.


ITEM 7. FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS

(a)      Not applicable.

(b)      Not applicable.

(c)      Exhibit 99.  Text of Press Release dated September 11, 1997.





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                                   SIGNATURES

         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.


                                      ORBITAL SCIENCES CORPORATION
                                 
                                 
                                 
Date:    September 12, 1997               By:   /s/ Jeffrey V. Pirone
                                             ----------------------------------
                                               Jeffrey V. Pirone
                                               Senior Vice President and
                                                  Chief Financial Officer
                                       




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                                 EXHIBIT INDEX





Exhibit No.                    Description
- -----------                    -----------
                
  99              Press Release dated September 11, 1997. (transmitted herewith)






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EX-99

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                                                                      Exhibit 99

FOR IMMEDIATE RELEASE
                                                  FOR MORE INFORMATION CONTACT
                                                  BARRON BENESKI (703) 406-5000


         ORBITAL TO SELL $90 MILLION OF CONVERTIBLE SUBORDINATED NOTES

(DULLES, VA 11 September 1997) -- Orbital Sciences Corporation (NASDAQ: ORBI)
today announced it will sell $90 million in 5% convertible subordinated notes
due October 2002 within the United States pursuant to Rule 144A of the U.S.
Securities Act of 1933, as amended, and outside the United States pursuant to
Regulation S under that Act.  The offering is expected to close September 16,
1997.  The company has granted the initial purchasers in the offering a 30-day
option to purchase up to an additional $10 million of notes to cover
over-allotments, if any.

The notes, which are non-callable for three years, will be convertible into
Orbital common stock at a conversion price of $28.00 per share, subject to
adjustment in certain events.  The notes will initially be convertible into a
total of 3,214,286 shares of common stock of the company (3,571,429 shares if
the initial purchasers' over-allotment option is exercised in full).

Orbital plans to use the net proceeds from the offering to realign its short-
and long-term capital structure, and for possible investments in new projects,
product lines or acquisitions or, if needed, to satisfy certain existing
contingent commitments.

Neither the notes nor the common stock of the company issuable upon conversion
of the notes has been registered under the Securities Act of 1933, as amended,
or any state securities laws.  Accordingly, these securities may not be offered
or sold in the United States or to or for the account of U.S. persons absent
registration or an exemption from the registration requirements of the
Securities Act of 1933, as amended, and applicable state securities laws.

This announcement is neither an offer to sell nor a solicitation to buy any of
these securities.

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





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