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                                                                   EXHIBIT 10.18



          U.S. GATEWAY EARTH STATION MAINTENANCE SERVICE AGREEMENT

                                   BETWEEN

                        ORBITAL SCIENCES CORPORATION

                                 LOCATED AT:

                            3380 SOUTH PRICE ROAD
                             CHANDLER, AZ  85248

                                     AND

                            ORBCOMM GLOBAL, L.P.

                                 LOCATED AT:

                          21700 ATLANTIC BOULEVARD
                              DULLES, VA  20166


                              AGREEMENT NUMBER:
                                  ORB/GES.2



                               EFFECTIVE DATE:
                               1 OCTOBER 1997


                           PERIOD OF PERFORMANCE:
                     1 OCTOBER 1997 TO 30 SEPTEMBER 1998
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                                   AGREEMENT

                                    BETWEEN

                          ORBITAL SCIENCES CORPORATION

                                      AND

                              ORBCOMM GLOBAL, L.P.

         This Agreement made as of this 1st day of October, 1997 between
Orbital Sciences Corporation ("Orbital" or "Seller"), with its principal
offices located at 3380 South Price Road, Chandler, AZ 85248, and ORBCOMM
Global, L.P., ("ORBCOMM" or "Buyer"), with its principal offices located at
21700 Atlantic Boulevard, Dulles, VA 20166.  The effective date of this
Agreement is October 1, 1997.  The parties agree as follows:


                                   ARTICLE I
                               STATEMENT OF WORK

         Consistent with the terms and conditions set forth herein, Seller
shall provide the necessary personnel, facilities, supplies and services in
accordance with the Statement of Work (the "SOW"), attached hereto as
Attachment 1, and as such SOW and specifications contained therein may be
modified from time to time by mutual agreement of the parties.  Seller shall
manufacture and/or procure and store for the period of performance as described
in Article II the spares identified in the Maintenance Support Spares list,
attached hereto as SOW Table 4-3, as such spares list may be modified by mutual
agreement of the parties.  Seller shall use its best efforts to meet the
Routine Maintenance Planning Schedule, attached herein as SOW Table 4-1.
Either party shall notify the other party of any schedule conflicts within ten
10 days prior to the schedule conflict date; provided that the parties
acknowledge and agree that schedule conflicts arising from the operation of the
ORBCOMM System may not be identifiable within such timeframe.  Seller shall use
its best efforts to meet the delivery schedule in the SOW.  If Seller
reasonably believes the schedule will not be met, Seller shall promptly notify
Buyer of the delay and the proposed delivery dates.


                                   ARTICLE II
                             PERIOD OF PERFORMANCE

         The period of performance for this Agreement shall be from October 1,
1997 through September 30, 1998.  Future maintenance service agreements beyond
September 30, 1998 may be separately negotiated on an annual basis.  Buyer
shall notify Seller of its desire to negotiate continued performance no later
than 60 days prior to the expiration of the term of this Agreement.





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                                  ARTICLE III
                       DELIVERABLE SUPPLIES AND SERVICES

         Set forth below are the tasks to be provided as described in the SOW
for the U.S. GES sites, defined as: Arcade, NY; Oscilla, GA; East Wanatchee, WA
and St. Johns, AZ.

1.       Routine Quarterly Maintenance
2.       Spares Program
3.       Site Representation
4.       Service Repair
5.       As Installed Shelter Documentation
6.       ORBCOMM Satellite Launch Support
7.       Special Projects


                                   ARTICLE IV
                        CONTRACT TYPE AND CONSIDERATION

         As described in Article III and the SOW, this Agreement consists of
seven CLINs that are separately priced.  Orbital shall deliver the services and
supplies in accordance with the SOW.  Orbital shall perform CLINs 1, 2, 3, 5
and 6 on a firm fixed price ("FFP") basis, and CLIN 4 on a time and materials
("T&M") basis.  CLIN 7 shall be negotiated by mutual agreement of the parties
on either a FFP or T&M basis, as each project is defined.

CLIN 1 - ROUTINE QUARTERLY MAINTENANCE          FFP               $180,736

         Services shall take place as described in the SOW and Routine
Maintenance Planning Schedule, SOW Table 4-1.

         Note:  All travel costs for the performance of Routine Quarterly
                Maintenance are included in the FFP set forth above.

CLIN 2 - SPARES PROGRAM                          FFP               $66,440

         Orbital shall manufacture, procure and maintain spares ("Spares") on
execution of this Agreement in accordance with the SOW and SOW Table 4-3.
Orbital shall receive, inspect, test and inventory spares in a controlled
stockroom.  ORBCOMM shall take ownership of each Spare after it is inspected,
tested and received into inventory at Orbital's Chandler, AZ facility in
accordance with the SOW.  ORBCOMM will furnish asset bar-code labels for each
Spare.

         Orbital shall notify ORBCOMM as each Spare is installed with the
appropriate asset information, such as: bar-code, serial number and
installation site.





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         Shipping costs to the U.S. GESs and insurance during such shipment are
not included in the FFP set forth above and will be handled as provided in
Article XIV.  While located in Orbital's controlled stockroom located in
Chandler, AZ, the Spares shall be covered by Orbital's all-risk and peril
insurance, which insurance shall cover the full replacement value thereof, the
cost of which shall be included in the FFP set forth above.

CLIN 3 - SITE REPRESENTATION                     FFP               $641,700

         Orbital shall maintain a local site representative and provide
maintenance of the site grounds for each US GES site (NY, WA, GA, AZ) in
accordance with the SOW.  Each site representative shall be responsible for
routine twice-weekly (8 hrs./day, 16 hrs./week) visits to their designated
site.  Orbital and ORBCOMM shall update the checklist for each site
representative to use during such routine visits on an as needed basis by
mutual agreement.  The site representatives shall be on 24 hour call for site
emergencies and must be able to reach his or her designated site within 6 hours
of notification.  Upon receipt by the site representative of notification of a
site emergency by Orbital, the site representative shall be required to
immediately deploy to the site.  The dispatching of the site representative by
Orbital and response to emergencies by the site representative shall be
accomplished within this CLIN.

         ORBCOMM shall provide up to $1,000 per site to Orbital for site petty
funds to enable local purchase of low cost, expendable items in accordance with
the SOW.

CLIN 4 - SERVICE REPAIR                          T&M*                   TBD

         On verbal authorization and authorization number from an ORBCOMM
Technical Manager, Orbital shall be authorized to expend the necessary labor,
material, shipping and travel costs to complete any service repair
requirements.  This CLIN includes any critical, major and minor repairs.

         NOTE:  Failures with ORBCOMM software, Torrey Modems and other items
not addressed in the SOW shall be identified and referred to ORBCOMM for
resolution.

         * Orbital's Time and Materials pricing under this Agreement including
this CLIN 4 shall be equal to the actual direct dollars (labor, material, ODC)
incurred, and the applicable fringe, overhead and G&A rates as described in
Orbital's Forward Pricing Rates and a 15% profit rate.  Orbital's published
Forward Pricing Rates shall be those rates used by Orbital's most favored
Government customers and submitted to the Defense Contract Audit Agency (DCAA).
Orbital represents that it operates under a U.S.  Government-approved
accounting system and establishes its published Forward Pricing Rates within
the Government's guidelines.  ORBCOMM shall be entitled to conduct audits,
through an independent auditor, to verify that Orbital's invoices have been
rendered in accordance with the terms of this Agreement including this CLIN 4.
Such auditor shall be required to sign an appropriate Non-Disclosure Agreement
pursuant to which such auditor will be precluded from disclosing to ORBCOMM
Orbital's proprietary Forward Pricing Rates.





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CLIN 5 - AS INSTALLED SHELTER DOCUMENTATION      FFP               $97,843

         Orbital shall develop drawings for the ORBCOMM
shelters/interconnections installed at the sites by ORBCOMM and not currently
covered by existing drawings.  The drawing package shall use the St. Johns,
Arizona site as the baseline.  Once the Arizona shelter drawings are completed,
Orbital will conduct a detailed survey at each of the other sites, identify and
document the specific differences from the "baseline" set of drawings.  ORBCOMM
shall determine whether unique drawings or changes for the other 3 sites are
wanted.  New drawings or changes to conform to baseline drawings will be an
add-on to this Agreement in accordance with the provisions of CLIN 7.

CLIN 6 - ORBCOMM SATELLITE LAUNCH SUPPORT        FFP               $64,311

         Orbital will provide one knowledgeable person at each site prior to
the next 2 ORBCOMM launches scheduled after the execution of this Agreement.
That individual shall remain at the site until 6 days after the launch, a total
of 7 days, not including travel time.  If the launch is delayed after the
person is deployed to the site, ORBCOMM will estimate the additional time that
the person will be required to remain at the site.  Additional travel time and
any extension will be administered as a Special Project in accordance with the
provisions of CLIN 7.

CLIN 7 - SPECIAL PROJECTS                        FFP/T&M               TBD

         As requested by ORBCOMM or initiated by Orbital, Orbital shall submit
proposals to ORBCOMM for potential projects that are identified as of the
effective date of this Agreement or as may be later identified.  Orbital's
proposals shall be valid for a period of 60 days from receipt by ORBCOMM.  The
contract type (FFP, T&M) shall be negotiated as appropriate to the project.
Orbital is not authorized to begin work on any special projects prior to
receipt of ORBCOMM contractual authorization.


                                   ARTICLE V
                                   INVOICING

         Orbital shall submit to ORBCOMM invoices to the address below.
Invoices for Firm Fixed Priced CLINs 1, 2, 3, 5 and 6 will be based on the
milestone payment schedule set forth in Attachment 2.  With respect to invoices
for time and material CLIN 4, Orbital shall invoice ORBCOMM on acceptance of
each repair as described in Article IV, CLIN 4.  As described in Article IV,
CLIN 7 will be invoiced as negotiated at a later date.  ORBCOMM shall pay such
invoices within 30 days from the date of receipt.  Third party billing for
maintenance service orders authorized by ORBCOMM for which a procurement
control number has been assigned shall be directly billed to ORBCOMM and shall
not be the responsibility of Orbital.





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                 ORBCOMM Global, L.P.
                 21700 Atlantic Boulevard
                 Dulles, VA  20166
                 Attention:  Controller

                 With a copy to:

                 ORBCOMM Global, L.P.
                 21700 Atlantic Boulevard
                 Dulles, VA  20166
                 Attention:  Collin MacDonald


                                   ARTICLE VI
                                    REPORTS

         Orbital shall submit all reports as required by the SOW to the
technical managers identified below.

                 ORBCOMM Global, L.P.
                 21700 Atlantic Boulevard
                 Dulles, VA  20166
                 Attention:   Mr. Brian Wallace
                     cc:      Mr. Collin MacDonald
                     cc:      Mr. Tom Edmonston


                                  ARTICLE VII
                               TECHNICAL MANAGERS

         (a)     The Technical Managers for this Agreement are:

                 Orbital Sciences Corporation
                 3380 South Price Road
                 Chandler, AZ.  85248
                 Technical Managers:  Mr. Charles Tracy  (602) 814-6820
                                      Mr. Richard Fahrner  (602) 814-6370
                                      Mr. Mark DiLello  (602) 814-6050

                 ORBCOMM Global, L.P.
                 21700 Atlantic Boulevard
                 Dulles, VA  20166





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                 Technical Managers: Mr. Brian Wallace
                     cc:             Mr. Collin MacDonald
                     cc:             Mr. Tom Edmonston

         (b)     ORBCOMM's technical managers are authorized to issue technical
         directions under this Agreement on behalf of ORBCOMM that provide
         details or otherwise more specifically defines work set forth herein.
         To be valid, the technical direction (i) must be issued in writing
         consistent with the general scope of work set forth in this Agreement;
         (ii) may not modify the SOW, change the express terms and conditions
         of this Agreement or issue a stop work order; and (iii) shall not
         commit ORBCOMM to any adjustment of the price or other provisions of
         this Agreement.


         (c)     In the event any ORBCOMM technical direction is interpreted by
         Orbital to constitute a change to the requirements hereunder in effect
         at the time of the direction, Orbital shall not implement such
         direction but shall:



                 (i)      Notify ORBCOMM promptly by telephone at the time of
                 such interpretation, which oral notification shall be
                 confirmed in writing within ten (10) business days after
                 Orbital's receipt of such direction.  Such notice shall
                 include the reasons on which Orbital bases its belief that the
                 technical direction constitutes a change to the requirement of
                 this Agreement.  If ORBCOMM is interested in pursuing such
                 technical direction, it shall within ten (10) business days of
                 receipt of Orbital's notice, provide a formal request for
                 Orbital's best estimate of changes to the Price, performance
                 time, specifications, delivery schedules and any other
                 contractual provisions that would result from implementing the
                 technical direction.

                 (ii)     If after reviewing the information presented pursuant
                 to subparagraph (i) above, ORBCOMM agrees with Orbital that
                 such direction is a change to the requirements of this
                 Agreement and ORBCOMM wishes to change such requirement,
                 ORBCOMM and Orbital shall negotiate a bilateral modification
                 to this Agreement to implement such change.

                 (iii)    Failure of ORBCOMM and Orbital to agree on whether
                 ORBCOMM's direction is technical direction or a change in the
                 requirements of this Agreement shall be a dispute and be
                 resolved in accordance with Article IX of this Agreement.





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                                  ARTICLE VIII
                                 NOTIFICATIONS

         Except as otherwise specified herein, all notices, request and other
communications required to be delivered to any party hereunder shall be in
writing (including any facsimile transmission or similar writing), and shall be
delivered to the persons addressed as follows:





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         (a)     If to Seller:

                 Orbital Sciences Corporation
                 3380 South Price Road
                 Chandler, AZ.   85248
                 Attention:       Ms. Debra B. Dreher
                                  Senior Contracts Administrator

         (b)     If to Buyer:

                 ORBCOMM Global, L.P.
                 21700 Atlantic Boulevard
                 Dulles, VA  20166
                 Attention:       Mary Ellen Seravalli
                   Senior Vice President and General Counsel

         with a copy to:

                 ORBCOMM Global, L.P.
                 21700 Atlantic Boulevard
                 Dulles, VA  20166
                 Attention:       Robert Vence
                 Senior Vice President Engineering & Operations

                                   ARTICLE IX
                                    DISPUTES

         (a)     Any material controversy or claim that may arise under, out
of, in connection with or relating to this Agreement or any breach hereof,
shall be submitted to a representative management panel of Buyer and Seller.
Each of Buyer and Seller may appoint up to three individuals to such panel.
Such appointments shall be made within ten (10) days of the receipt by the
appointing party of notice of the existence of such controversy or claim.  A
joint decision and agreement of such panel shall resolve the controversy or
claim.  If the panel is unable to resolve such matter within thirty (30) days
of the submission of such controversy or claim to such individuals, either
party may remove the controversy or claim for arbitration in accordance with
Article IX(b).

         (b)     Any material controversy or claim that is not resolved under
Article IX(a) shall be settled by final and binding arbitration in the
Commonwealth of Virginia, in accordance with the then existing United States
domestic rules of the American Arbitration Association (to the extent not
modified by this Article IX).  In the event that more than one claim or
controversy arises under this Agreement, such claims or controversies may be
consolidated in a single arbitral proceeding.  The arbitral tribunal shall be
composed of three arbitrators.  Each of Buyer and Seller shall appoint one
arbitrator.  If any party shall fail to appoint an arbitrator within thirty
(30) days from the date on which another party's  request for arbitration has
been communicated to the first party,





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such appointment shall be made by the American Arbitration Association (the
"AAA").  The two arbitrators so appointed shall agree upon the third arbitrator
who shall act as chairman of the arbitral tribunal and who shall be an expert
in the construction, operation and maintenance of electro-mechanical,
computer-controller tracking antenna systems used in satellite-based
communications networks.  If the two appointed arbitrators fail to nominate a
chairman within ten (10) days from the date as of which both arbitrators shall
have been appointed, such chairman shall be selected by the AAA.  In all cases,
the arbitrators shall be fluent in English.  Judgment upon any award rendered
by the arbitrators may be entered in any court having jurisdiction or
application may be made for judicial acceptance of the award and an order of
enforcement, as the case may be.  The parties agree that if it becomes
necessary for any party to enforce an arbitral award by a legal action or
additional arbitration or judicial methods, the party against whom enforcement
is sought shall pay all reasonable costs and attorneys' fees incurred by the
party seeking to enforce the award.


                                   ARTICLE X
                     TERMINATION FOR ORBCOMM'S CONVENIENCE

         ORBCOMM may terminate this Agreement, in whole or in part, at any time
for its convenience by providing written notice to Orbital ("Termination
Notice").  The Termination Notice will indicate if any completed but not yet
accepted supplies and/or services as well as work-in process will be purchased
by ORBCOMM.  On receipt of a Termination Notice, Orbital shall immediately stop
work as specified therein, and, within 30 days thereafter, submit a termination
claim ("Termination Claim") to ORBCOMM.  The Termination Claim shall be for (a)
the applicable prices herein for any completed and accepted work not yet paid
for by ORBCOMM; (b) the applicable prices herein for any completed but not yet
accepted work to be purchased by ORBCOMM; (c) Orbital's reasonable costs for
any work-in-process to be purchased by ORBCOMM; and (d) Orbital's reasonable,
non-recoverable costs for any work performed that ORBCOMM will not purchase.
The costs shall not exceed the applicable prices herein for such work and
Orbital shall use all reasonable efforts to mitigate any non-recoverable costs
pursuant to (d).  Orbital shall provide ORBCOMM with access to Orbital's
premises and records to verify the costs submitted as part of the Termination
Claim.  If Orbital fails to submit a Termination Claim within the 30-day period
set forth above, ORBCOMM may determine, on the basis of information available
to it, the amount, if any due to Orbital with respect to the Termination
Notice, and such determination shall be final and binding on the parties  This
clause shall not apply if the Agreement is terminated, in whole or in part, due
to Orbital's default.


                                   ARTICLE XI
                            TERMINATION FOR DEFAULT

         (a)     Subject to paragraphs (b), (c), (d) and (e) below, Buyer may
by written notice of default to the Seller, terminate the Agreement in whole or
in part if the Seller fails to:





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                 (i)  Comply with any of the covenants and agreements set forth
         in this Agreement and such failure shall not be cured within twenty
         (20) days of the receipt by Seller of written notice at such default;
         or

                 (ii)  Make progress, so as to endanger performance of this
         Agreement, and such failure is not cured within twenty (20) days of
         receipt by Seller of written notice of such default.

         (b)     If Buyer terminates this Agreement in part for default, Buyer
shall (a) pay the applicable prices herein for any completed or partially
completed and accepted work not yet paid for; (b) pay Orbital's reasonable
costs for any work-in-process or non-recoverable costs for any work performed
unrelated to the reason for default.  Seller shall continue the work not
terminated.

         (c)     If this Agreement is terminated for default (i) Buyer may
require Seller to transfer title and deliver to Buyer any (A) completed or
partially completed work deliverable under this Agreement and not previously
delivered to, and accepted by, Buyer to the extent Seller received payment
therefore, and (B) other property, including agreement rights, specifically
produced or acquired for the terminated portion of the Agreement; and/or (ii)
Buyer may direct Seller to repay to Buyer any amounts paid by Buyer not covered
by the deliveries specified in this sub-section (c) above.  Seller shall take
into account in its determinations as to the amount of the progress payments to
be repaid to Buyer, the extent to which Buyer exercises its rights under this
sub-section (c).

         (d)     After termination, if it is determined that Seller was not in
default, or that the default was excusable, the parties shall negotiate an
equitable settlement.  Failure to agree on an equitable adjustment shall
constitute a dispute and shall be resolved in accordance with Article IX of
this Agreement.

         (e)     Subject to the terms and conditions of Article XIX, the rights
and remedies of Buyer and Seller under this Article XI are in addition to any
other rights and remedies provided by law or under this Agreement.


                                  ARTICLE XII
                                    CHANGES

         (a)     Upon mutual agreement of both parties, Buyer by modification
may make changes within the general scope of this Agreement in any of the
following areas:

                 (i)      Schedule of Routine Maintenance Service;
                 (ii)     Schedule of Spares delivery;
                 (iii)    Final quantity of delivered Spares ;
                 (iv)     Additional Supplies or Services





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         (b)     If any change causes an increase or decrease in the cost of,
or the time required for performance of any part of the work, whether or not
directly changed by the order, Buyer and Seller shall negotiate an equitable
adjustment to the agreed price, delivery schedule, or other provision of this
Agreement.  Seller shall not begin the work as changed until a bilateral
modification has been issued.

         (c)     Failure to agree to any adjustment shall be a dispute and
settled in accordance with Article IX of this Agreement.


                                  ARTICLE XIII
                              ORDER OF PRECEDENCE

         (a)     Inconsistencies between or among Articles of this Agreement
and/or any attachments shall be resolved in the following order of precedence:

                 (i)      Articles 1 through XXVI of this Agreement;
                 (ii)     Attachment 1, SOW (including all documents referenced
                          therein)
                 (iii)    ORBCOMM GES Operations & Maintenance Manual, TM-11292
                 (iv)     ORBCOMM GES Acceptance Test Procedure, 10664
                 (v)      Standard Operating Procedure (SOP), TM-2945
                 (vi)     Product Assurance Manual, TM-110
                 (v)      Attachment 2, Payment Schedule

         (b)     The Attachments hereto are incorporated by reference into this
Agreement.


                                  ARTICLE XIV
                           F.O.B. POINT AND SHIPMENTS

         All Spares are sold and delivery made F.O.B. origin, defined as
Orbital's facility in Chandler, AZ.  Packaging shall be according to Orbital's
best commercial, but no less than reasonable, practices.  Shipping costs to the
U.S. GES sites and insurance during shipment to such site shall be paid by
ORBCOMM, and where possible shall be charged against ORBCOMM's airbill account
number.


                                 ARTICLE XV
              INSPECTION AND ACCEPTANCE OF SERVICES AND SPARES

         Acceptance of services (CLINs 1, and 3-7) shall take place on the date
services are rendered including all required reports and documentation
associated therewith.  Acceptance of Spares (CLIN 2) shall take place in
accordance with SOW Table 4-3, and upon delivery of the Spares at Orbital's
Chandler, AZ. facility and completion of testing.  A certificate demonstrating
completion will be delivered to ORBCOMM within five business days of such
testing.





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                                  ARTICLE XVI
                                     TAXES

         The prices set forth herein do not include sales, use, excise or other
federal, state or local taxes.  In addition to the price, the amount of any
present or future sales, use, excise or other tax levied upon or measured by
the sale, the sales price or the use of the Goods or performance  of the
services required hereunder shall be paid by Buyer, unless Buyer supplies a tax
exemption certificate acceptable to taxing authorities.


                                  ARTICLE XVII
                             INTELLECTUAL PROPERTY

         To the extent Seller has any right or title to any designs, inventions
(whether or not patented), processes, technical data, drawings, intellectual
property and/or confidential information related to the Goods or services to be
purchased by Buyer hereunder, they shall remain the exclusive property of
Seller notwithstanding Seller's disclosure of any information or delivery of
any Goods to or the performance of any services for Buyer or Buyer's payment to
Seller.  The parties acknowledge the execution of the Restated Proprietary
Information and Non-Competition Agreement dated as of September 12, 1995 among
Orbital, Orbital Communications Corporation, Teleglobe Inc., Teleglobe Mobile
Partners, ORBCOMM, ORBCOMM USA, L.P. and ORBCOMM International Partners, L. P.
and agree to abide by the terms thereof.


                                 ARTICLE XVIII
                              WARRANTY AND REMEDY

         (a)     Seller represents and warrants that:  (i) it has and will have
sole and good legal and equitable title to any and all goods (including the
Spares) to be delivered pursuant to this Agreement including the SOW (the
"Goods"), free and clear of any and all security interests, liens, claims,
charges and encumbrances of any kind or nature whatsoever, together with full
power and lawful authority to sell and deliver the Goods and services to be
furnished under this Agreement including the SOW, (ii) neither the performance
of the services nor the furnishing of the Goods hereunder shall in any way
constitute an infringement  or other violation of any copyright, trade secret,
trademark, patent, invention, proprietary information, nondisclosure agreement
or other rights of any third party, and (iii) the furnishing of the Goods and
the performance of the services hereunder shall be in compliance with all
applicable United States laws, rules and regulations.

         (b)     Seller represents and warrants that each of the Goods
furnished by it, or to the extent applicable, the services performed by it
under this Agreement shall be in good operating condition and be free of
defects in material and workmanship at the time of delivery.  The warranty
period ("Warranty Period") shall be a period of one year after completion of
manufacture and initial testing of Orbital-manufactured Goods or, for non
Orbital-manufactured Spares, a period of six months after initial testing
thereof by Orbital on receipt in accordance





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with the SOW.  Any vendor Goods that have vendor warranties extending beyond
six months shall be automatically extended to Buyer.  Seller's obligation
during the Warranty Period shall be limited to repair or replacement of any
defective Goods.

         (c)     Notice of all claimed defects must be provided in writing to
Seller within the applicable Warranty Period with respect to each Good.  Seller
shall determine to its satisfaction, after inspection, that the Good or part
thereof was, in fact defective.  If it is necessary to repair Goods at Seller's
Chandler, AZ. facility, Seller shall pay shipping and insurance expense to
return spares to Seller's Chandler, AZ. facility.  Any remaining warranty for
any Goods or part thereof repaired or replaced shall not extend the original
warranty period.  THE WARRANTY SET FORTH HEREIN IS BUYER'S EXCLUSIVE REMEDY
AGAINST SELLER FOR DEFECTIVE GOODS AND IS IN LIEU OF ALL OTHER WARRANTIES,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE  IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

         (d)     The warranty set forth herein shall not extend to any Goods
that, upon Seller's examination are found to have been (i) mishandled, misused,
subjected to negligence, accident or abuse (other than as a result of actions
taken by Seller or one of its representatives); (ii) installed, operated or
maintained by Buyer contrary to Seller's specifications or instructions or
otherwise used improperly; (iii) tampered with or damaged as evidenced by, for
example, broken seals, unauthorized modifications, damaged packaging containers
and the like; (iv) repaired/altered by anyone other than Seller or its
representatives without Seller's express advance approval; or (v) delivered to
Seller not in conformance with notice requirements set forth in this Article
XVIII, provided that so long as Seller receives written notice from Buyer of a
claimed defect within the Warranty Period, Buyer shall be deemed to have
complied with the notice requirements set forth in this Article XVIII.  If
Seller determines that the items were found to conform to the specifications
and requirements of this Agreement, they will be repaired/replaced/shipped at
Buyer's expense.


                                  ARTICLE XIX
                            LIMITATION OF LIABILITY

         (a)     NOTWITHSTANDING ANYTHING CONTAINED HEREIN TO THE CONTRARY, IN
NO EVENT SHALL EITHER PARTY HAVE ANY OBLIGATION, LIABILITY, RIGHT, CLAIM OR
REMEDY TO THE OTHER UNDER THIS AGREEMENT FOR LOSS OF USE, REVENUE OR PROFIT OR
FOR ANY OTHER INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES.

         (b)     Regardless of fault, under no circumstances shall Seller be
liable for any damages greater than the price of the Goods sold or services
performed  hereunder for any claim made,  whether arising from Seller's breach
of contract, breach of express or implied warranty, arising in tort, at law or
in equity including any law giving rise to a claim of strict liability or for
any other cause.





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                                   ARTICLE XX
                              AMENDMENT AND WAIVER

         Except as provided otherwise herein, this Agreement may not be amended
nor may any rights hereunder be waived except by an instrument in writing
signed by the parties hereto.  Failure of either party to enforce, at any time,
any of the provisions of this Agreement shall not constitute a waiver of such
provisions, or a waiver of the right of the respective party to enforce any or
all provisions.


                                  ARTICLE XXI
                                 APPLICABLE LAW

         This Agreement, including all attachments hereto, shall be construed
in accordance with and governed by the laws of the Commonwealth on Virginia,
USA, without giving effect to the provisions, policies or principles thereof
relating to choice or conflict of laws.


                                  ARTICLE XXII
                         BINDING EFFECT AND ASSIGNMENT

         This Agreement shall be binding upon and shall inure to the benefit of
the parties and their respective successors and permitted assigns.  Neither
this Agreement nor any interests or obligations hereunder shall be assigned or
transferred (by operation of law or otherwise) to any person without the prior
written consent of the other party.


                                 ARTICLE XXIII
                                 FORCE MAJEURE

         Neither party shall be responsible to the other for any failure or
delay in performance or delivery that is the result of an act of God, the
public enemy, embargo, governmental act, fire, accident, war, riot, strikes,
inclement weather or other causes of a similar nature that are beyond the
control of the parties.  In the event of such occurrence, this Agreement shall
be amended by mutual agreement to reflect to an extension in the period of
performance and /or time of delivery.  Failure to agree on an equitable
adjustment shall be considered a dispute and resolved in accordance with
Article IX of the Agreement.  However, Orbital agrees to repair or replace any
Spares, as identified in SOW Table 4-3, that are damaged or destroyed while in
Orbital's Chandler, AZ facility during the performance period of this
Agreement.





                                    13 of 14
<PAGE>   16
                                  ARTICLE XXV
                                ENTIRE AGREEMENT

         This Agreement, including attachments hereto, constitutes the entire
agreement among the parties with respect to the subject matter hereof, and
supersedes any prior writing or agreement or understanding among the parties
with respect to the subject matter hereof and shall not be varied,
supplemented, qualified or interpreted by any prior course of dealing between
the parties or by any usage of trade.


                                  ARTICLE XXVI
                                   SIGNATURES

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the day and year first above written.

ORBITAL SCIENCES  CORPORATION               ORBCOMM GLOBAL, L.P.



By                                          By
  ----------------------------------          ---------------------------------
  Name:  Ms. Debra B. Dreher                  Name:  Mr. Alan L. Parker
  Title: Senior Contracts Administrator       Title: President





                                    14 of 14
<PAGE>   17


                                  ATTACHMENT 2

                           MILESTONE PAYMENT SCHEDULE


<TABLE>
<CAPTION>
         MILESTONE                                                  PAYMENT
         ---------                                                  -------
<S>                                                                 <C>
1.       Completion of 1st Quarter                                  25% of CLIN 1 Value
         Maintenance Support

2.       Completion of 2nd Quarter                                  25% of CLIN 1 Value
         Maintenance Support

3.       Completion of 3rd Quarter                                  25% of CLIN 1 Value
         Maintenance Support

4.       Completion of 4th Quarter                                  25% of CLIN 1 Value
         Maintenance Support

5.       Place P.O.s for vendor spares and                          25% of CLIN 2 Value
         and Orbital manufactured spares.

6.       Receipt, Test and Acceptance of Spares                     75% of CLIN 2 Value

7.       Completion of 1st Quarter                                  25% of CLIN 3 Value
         Site Representation Support

8.       Completion of 2nd Quarter                                  25% of CLIN 3 Value
         Site Representation Support

9.       Completion of 3rd Quarter                                  25% of CLIN 3 Value
         Site Representation Support

10.      Completion of 4th Quarter                                  25% of CLIN 3 Value
         Site Representation Support

11.      Completion of Preliminary                                  25% of CLIN 5 Value
         Shelter Drawings

12.      Delivery of Released Baseline                              50% of CLIN 5 Value
         Drawings

13.      Delivery of Red-Lined Drawings                             25% of CLIN 5 Value
         for other 3 U.S. GES sites

14.      Completion of 1st Launch                                   50% of CLIN 6 Value

15.      Completion of 2nd Launch                                   50% of CLIN 6 Value
</TABLE>