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                               AMENDMENT NO. 9 TO
                      ORBCOMM SYSTEM PROCUREMENT AGREEMENT

     This Amendment No. 9 ("Amendment No. 9") to the ORBCOMM System Procurement
Agreement is entered into as of the 30th day of June, 1999 between ORBCOMM
Global, L.P. ("ORBCOMM Global") and Orbital Sciences Corporation ("Orbital").

                                   WITNESSETH:

     WHEREAS, the parties previously entered into the ORBCOMM System Procurement
Agreement dated September 12, 1995 (the "Procurement Agreement") and Amendments
No. 1, No. 2, No. 3, No. 4, No. 5, No. 6, No. 7 and No. 8 thereto; and

     WHEREAS, the parties wish to set forth their agreement pertaining to an
equitable price adjustment to the Procurement Agreement for changes made and
associated costs incurred by Orbital under the Procurement Agreement from
January 1, 1999 to June 30, 1999 and additional services to be performed through
September 30, 1999.

     NOW, THEREFORE, the parties agree as follows:

                             ARTICLE 1 - DEFINITIONS

     Terms used herein and not otherwise defined shall have the meanings
assigned thereto in the Procurement Agreement.

                             ARTICLE 2 - AMENDMENTS

     Section 2.1 Section 3.1(a) of the Procurement Agreement shall be amended to
add a new subparagraph (vi) immediately following subparagraph (v) that reads as
follows:

     "(vi) Price Adjustment Changes From
           January 1, 1999 To September 30, 1999
           Outside the General Scope of the Agreement"           $ 3,181,995
                                                                 -----------


     Section 2.2 Section 3.1(a) of the Procurement Agreement shall be amended to
delete the "TOTAL" price of $166,323,821 set forth therein and to replace it
with the new "TOTAL" price of $169,505,816.

     Section 2.3 Section 4.1(b)(i) of the Procurement Agreement shall be deleted
in its entirety and replaced with the following:

     "(i) Orbital shall be entitled to invoice ORBCOMM Global on a monthly basis
     for a maximum of 90% of its costs incurred during such month, other than
     costs associated with Sections 3.1(a)(iv), 3.1(a)(v), 3.1(a)(vi), 3.1(c)
     and 3.1(d), plus to




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     the extent permitted by Section 4.1(f), such portion of the cost in excess
     of the maximum amount to be invoiced to ORBCOMM Global in accordance with
     such Section 4.1(f) and not previously invoiced and paid; provided,
     however, that Orbital shall not be entitled to invoice ORBCOMM Global under
     Section 4.1(a) and this Section 4.1(b)(i) in a cumulative total amount
     greater than $125,884,929."

     Section 2.4 Section 4.4(ii) of the Procurement Agreement shall be deleted
in its entirety and replaced with the following:

     (ii) Notwithstanding anything in this Section 4 to the contrary, ORBCOMM
     Global agrees to pay to Orbital the principal amount of (a) $48,773,822 for
     work performed from October 1, 1997 to December 31, 1998 but not yet
     invoiced and (b) $7,181,995 for work performed from January 1, 1999 to June
     30, 1999 but not yet invoiced and out of scope work to be performed through
     September 30, 1999, which amounts, collectively, include the costs set
     forth in Sections 3.1(a)(v) and (vi), on the earlier of

          (x)  within thirty (30) days from the date of receipt of invoice,
               provided that, Orbital shall not submit an invoice for amounts
               set forth under Section 4.4(ii)(b) prior to September 30, 1999;
          (y)  December 31, 1999; or
          (z)  five (5) days after receipt of net proceeds by ORBCOMM Global of
               at least $100,000,000 from any equity issuance (excluding stock
               options) or debt financings of ORBCOMM Global or ORBCOMM
               Corporation."

                            SECTION 3 - MISCELLANEOUS

     Section 3.1 This Amendment No. 9 shall be construed in accordance with and
governed by the laws of the Commonwealth of Virginia, without giving effect to
the provisions, policies or principles thereof related to choice or conflict of
laws.

     Section 3.2 No changes to the Procurement Agreement are authorized hereby
except as otherwise specified in this Amendment No. 9.




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     IN WITNESS WHEREOF, the parties have executed this Amendment No. 9 as of
the day and year first above written.


                                          ORBCOMM GLOBAL, L.P.

                                          By:_______________________________
                                             Name:
                                             Title:

                                          ORBITAL SCIENCES CORPORATION

                                          By:_______________________________
                                             Name:  Jeffrey V. Pirone
                                             Title: Executive Vice President and
                                                    Chief Financial Officer