<PAGE>
 
                                                                    EXHIBIT 10.9

[LOGO OF IRIDIUM]    IRIDIUM(R) SERVICE PROVIDER AGREEMENT
                            (Including ICRS Option)

     THIS IRIDIUM SERVICE PROVIDER AGREEMENT is dated as of December 1, 1997, 
                                                            ----------------
and is by and between Iridium U.S., L.P. D/B/A Iridium North America ("INA"), 
and SkySite Communications Corporation, ("Service Provider").
    ----------------------------------

     Whereas, INA has been authorized by Iridium LLC., a Delaware, USA, limited 
liability company, ("Iridium"), to provide IRIDIUM(R) mobile communications 
services, including IRIDIUM Cellular Roaming Services ("ICRS"), in the Service 
Area (as defined herein); and

     Whereas, in accordance with the terms of this Agreement, Service Provider 
wishes to be authorized by INA to sell and market such IRIDIUM Services on a 
non-exclusive basis, to various parties in the Service Area (as defined herein),
and to sell or lease and maintain the equipment units of the IRIDIUM Subscriber 
Unit Segment necessary for utilizing such IRIDIUM Services, and INA wishes to 
authorize Service Provider to extend such IRIDIUM Services; and

     Whereas, Service Provider and Iridium recognize and acknowledge that the 
provision of ICRS by Service Provider is subject to its exercise of the option 
set forth in Article 6, ICRS Option, hereof; and
                        -----------

     NOW, THEREFORE, in consideration of the mutual agreements and 
understandings herein contained, the parties hereto agree as follows:

1.   Certain Definitions
     -------------------

     In addition to terms defined throughout this Agreement, as used herein, the
following terms shall have the following respective meanings:

     "$" means U.S. Dollars.
      -

     "Affiliate" of any Person means any other Person, directly or indirectly 
      ---------
controlling or controlled by or under direct or indirect common control with 
such Person. For the purposes of this definition, (i) "control" when used with 
respect to any Person means the power to direct the management and policies of 
such Person, directly or indirectly, whether through the ownership of voting 
securities, by contract, or otherwise; (ii) the terms "controlling" and 
"controlled" have meanings correlative to the foregoing; and (iii) a Person 
shall be deemed to be controlled by any other Person which owns more than 15% of
such Person's outstanding Common Stock or other equity securities or which has 
the right, contractually or otherwise, to select more than 15% of the members of
such Person's board of directors.

Revised: 12/1/1997    Iridium Service Provider Agreement            Page 1 of 13
                      SkySite Communications Corporation
<PAGE>
 
     "Confidential Information" means all confidential information of INA,
      ------------------------
     Service Provider, or Iridium including without limitation: this Agreement
     and its terms and conditions; all manuals and training materials provided
     by any party; the names, addresses, and telephone numbers of all
     Subscribers or prospective Subscribers and all lists or other records
     containing any such information; all financial and business information
     relating to any party, including without limitation all market analyses and
     market expansion plans, all revenue and profit analyses and all commission
     structures and statements; all technical information relating to INA,
     Iridium, IRIDIUM Services, including without limitation all implemented or
     planned product and service improvements or changes; information provided
     to Service Provider by INA or provided to INA by Service Provider which
     either party has designated as confidential; and all other information not
     generally known to the public relating to INA's business, Service
     Provider's business, IRIDIUM Services, Subscribers and prospective
     Subscribers.

     "Commencement Date" means date of commercially available service, intended
      ------------------
     to be September 23, 1998.

     "Correspondent" means an Administration or Recognized Private Agency as
     --------------
     prescribed in the Regulations of the International Telecommunications Union
     as amended from time to time or other entity which operates a
     telecommunications installation outside Service Area which provides
     services incidental to the provisions of the IRIDIUM Services.

     "Default" shall include but not be limited to: (i) the insolvency or
     --------
     initiation of bankruptcy or receivership proceedings by or against either
     party hereto; (ii) the execution of an assignment for the benefit of
     creditors or the seeking of relief by either party hereto under any
     applicable bankruptcy, organization, moratorium or similar debtor relief
     laws (it being understood that the execution of any third party financing
     agreement(s) shall not constitute an event of Default hereunder); (iii) the
     failure of Service Provider to pay any sum owed to INA hereunder within 60
     days after receipt of invoice, and the continuance thereof for 10 days
     after written notice has been given by INA to Service Provider; (iv) the
     failure by Service Provider or INA, as the case may be, to materially
     perform or observe any term, condition or covenant to be performed by such
     party hereunder, which failure has not been cured within 60 days after
     receipt of written notice; (v) the appointment of a receiver for Service
     Provider or INA or any of its respective assets or properties, which has
     not been dismissed, vacated or stayed within 30 days of such appointment;
     or (vi) the assignment of this agreement by either party hereto, if not
     performed pursuant to paragraph 12 hereto.

     "ESN" means the electronic serial number that is "burned" in a cellular
     ----
     telephone set by the manufacturer or by Iridium.

Revised: 12/1/1997    Iridium Service Provider Agreement            Page 2 of 13
                      SkySite Communications Corporation
<PAGE>
 
     "Government" means any nation or government, any state or other political
     -----------
     subdivision thereof, any ministry thereof, any wholly-owned Person thereof,
     and any entity exercising executive, legislative, judicial, regulatory or
     administrative functions of or pertaining to government.

     "ICRS" means Iridium Cellular Roaming Services, as specified by Iridium
     -----
     from time to time.

     "ICRS Option" means the option offered to Service Provider as set forth in
     ------------
     Article 6, ICRS Option, of this Agreement.
     ----------------------

     "IRIDIUM Services" means the IRIDIUM(R) mobile communication services as
      ----------------
     specified in Exhibit C hereto and, as used in this Agreement, includes ICRS
     provided that Service Provider has exercised the ICRS Option.

     "IRIDIUM System Practices" hereinafter ("ISP") means the set of
      -------------------------                ---
     guidelines, recommendations, rules, and other instructions related to
     technical and business matters associated with operation and use of the
     IRIDIUM Communications System, and the provision of IRIDIUM Services,
     including the mandatory ISP's set forth in Exhibit A hereto, in each case,
     however, as the same may be expressly amended, revised or supplemented in
     writing by Iridium from time to time and delivered by INA to Service
     Provider.

     "ISU" and "IRIDIUM(R) Subscriber Unit" means the individual equipment units
      ---       --------------------------
     used by IRIDIUM subscribers for purposes of initiating and receiving
     communications through the IRIDIUM Communications System and, as used in
     this Agreement, includes terrestrial mobile equipment units capable of
     accessing ICRS provided Service Provider has exercised the ICRS Option.

     "MIN" means the mobile identification number which is assigned by Iridium 
     -----
     to registered customers of ICRS.

     "Person" means an individual, a partnership, a corporation, an association,
     -------
     a joint stock company, a trust, a joint venture, an unincorporated
     organization or a Government.

     "PSTN" means a Public Switch Telephone Network.
     -----

     "SIM" means a Subscriber Information Module which contains customer
     ----
     information and, when used with an IRIDIUM(R) certified ISU enables access
     to the IRIDIUM Services.

     "Service Area" means the geographic region(s) of the United States of 
     -------------
     America, Puerto Rico and Bermuda.

Revised: 12/1/1997    Iridium Service Provider Agreement            Page 3 of 13
                      SkySite Communications Corporation
<PAGE>
 
      "Subscriber" means the Person who enters an agreement with Service
       ---------- 
       Provider for the right to access and use the IRIDIUM Services.

      "Tail Charges" mean the costs imposed by the PSTN for delivery and/or 
       ------------
      receipt of communications to or from the IRIDIUM(R) system.

2.    Appointment as Service Provider
      -------------------------------

      INA hereby appoints Service Provider as an authorized non-exclusive
      Service Provider of IRIDIUM Services subject to the terms and conditions
      provided herein, and Service Provider hereby accepts such appointment.
      Pursuant to such appointment, Service Provider shall with respect to the
      Service Area, and only in and with respect to such Service Area, use its
      reasonable efforts to market and sell access to and usage of IRIDIUM
      Services to Subscribers pursuant to the terms of this Agreement and to
      such terms and conditions as provided in the applicable mandatory ISP's.

3.    Service Provider Obligations
      ----------------------------

      A.   Subject to the provisions of Article 4.A., Service Provider shall
           obtain and maintain, at its own expense, all regulatory and legal
           authorizations, licenses, approvals certifications and permits,
           Governmental or otherwise, necessary for Service Provider and its
           employees to provide IRIDIUM Services in the Service Area and to
           perform its duties hereunder, including Authorization to carry
           (including transborder), operate and use ISUs.
           
      B.   Service Provider shall be solely responsible for and indemnify INA
           for all taxes, tariffs and surcharges, if any, arising from the
           provision of IRIDIUM Services by Service Provider to its customers in
           the Service Area.
           

      C.   Service Provider shall provide quarterly reports to INA regarding the
           marketing and sales activities undertaken pursuant to its obligations
           to market and sell IRIDIUM Services in the Service Area.

      D.   Service Provider shall perform all accounting, billing and
           collections activities necessary respecting its customers and shall
           be solely responsible for all expenses related to the performance of
           such services.

      E.   Service Provider shall provide the IRIDIUM Services specified in the
           applicable mandatory ISP's.

      F.   Service Provider shall provide its IRIDIUM satellite services
           Subscribers with only IRIDIUM(R) approved ISU's and Service Provider
           shall provide such equipment pursuant to the procedures and
           conditions specified in the mandatory ISP's set forth. Service
           Provider shall provide warranty

Revised: 12/1/1997        Iridium Service Provider Agreement    Page 4 of 13
                          SkySite Communications Corporation

<PAGE>
 
          and repair services for IRIDIUM approved ISU's, as provided for in the
          applicable mandatory ISP's.

     G.   Service Provider shall comply with the applicable mandatory ISP's. Any
          proposed change or addition to the mandatory ISP's shall be subject to
          the mutual agreement of INA and the Service Provider, except as
          provided in this paragraph. In the event a proposed change or addition
          to the mandatory ISP's is determined by Iridium to be required to
          avoid or correct any degradation or impairment of the IRIDIUM
          Communications System or the IRIDIUM services, Service Provider agrees
          to (i) comply with such change or addition or (ii) promptly notify INA
          of Service Provider's decision not to comply, in which event INA shall
          have the option to terminate this Agreement by providing written
          notice to Service Provider. Service Provider shall not knowingly or
          willfully engage in actions to discredit, dishonor, reflect adversely
          upon or in any manner injure the reputation of INA, Iridium or the
          IRIDIUM Services.

     H.   The Service Provider shall provide a 15 month rolling forecast of
          subscribers and minutes of use upon execution of this agreement, whose
          initial forecast is specified in Exhibit D. This forecast will be
          updated at the commencement date and every 3 months thereafter and
          will be provided to INA as a notice in accordance with Paragraph 14 of
          this agreement.

4.   INA Obligations
     ---------------

     A.   INA will use reasonable efforts to provide and maintain the
          availability of and access to the IRIDIUM Services for the Service
          Provider and its Subscribers including, if Service Provider has
          exercised the ICRS Option hereunder, appropriate and necessary ICRS
          billing, signaling and network access.

     B.   In accordance with the applicable ISP's, INA shall provide Service
          Provider with the number of SIMS and, if Service Provider has
          exercised the ICRS Option, the number of MIN/ESN pairs as are
          reasonably required by the Service Provider. Service Provider may
          request a further allocation of SIMS and, if applicable, MIN/ESN pairs
          and INA may provide such SIMS and MIN/ESN pairs as INA in its
          determination, after discussion with Service Provider, considers to be
          reasonable with respect to the availability of SIMS and MIN/ESN pairs
          and the size of Service Provider's anticipated Subscriber base.

     C.   All SIMS and MIN/ESN pairs provided to Service Provider hereunder
          remain the property of INA or Iridium (as applicable) and do not
          become the property of the Service Provider or the Service Providers
          Customers. The risks and financial liabilities associated with the
          SIMS and MIN/ESN pairs distributed pursuant to this Agreement shall
          pass from INA to the

 Revised: 12/1/1997        Iridium Service Provider Agreement    Page 5 of 13
                          Skysite Communications Corporation


<PAGE>

        Service Provider upon the receipt of the SIM and MIN/ESN pairs by the
        Service Provider. These risks and financial liabilities may include, but
        are not necessarily limited to authorized or fraudulent usage.

    D.  Subject to the applicable ISP's, INA shall provide to Service Provider,
        or arrange for the provision of, Iridium approved ISU's, including ICRS
        terrestrial mobile terminal equipment if Service Provider has exercised
        the ICRS Option. Service Provider is not required to purchase ISUs from
        INA, but any ISUs purchased must be Iridium-approved. If INA, however,
        does provide Iridium-approved ISUs to Service Provider, such ISUs shall
        be provided under a separate written agreement.

5.  Activations and Deactivations
    -----------------------------

    The Service Provider shall comply with all applicable procedures governing
    the activation and deactivation of IRIDIUM Services and equipment as set
    forth in the applicable mandatory ISP's, and INA may in its discretion, with
    believed justification, and with reasonable notice to Service Provider,
    refuse to activate any Service or any SIM or MIN/ESN pair or deactivate or
    suspend all or part of any Service or SIM or MIN/ESN pair.

6.  ICRS Option
    -----------

    Service Provider is hereby granted the option to offer the ICRS. Service
    Provider may exercise this option on the Commencement Date of this
    Agreement, or such later date as the Parties may otherwise agree in writing,
    by signing on the ICRS Option Acceptance line, below, which signature shall
    constitute a binding commitment on the part of Service Provider to provide
    ICRS in accordance with the applicable terms of this Agreement, including
    the applicable provisions of the IRIDIUM System Practices set forth in
    Exhibit A hereto.

7.  Term of Agreement; Renewal
    --------------------------

    This Agreement shall become effective as of the date first noted above and
    continue for a period of three (3) years after the Commencement Date (the
    "initial term"), unless terminated as provided herein. It shall
    automatically be renewed for successive one-year periods unless either party
    gives at least six (6) months advance written notice of its intention not to
    renew.

8.  Intellectual Property
    ---------------------

    Service Provider acknowledges that neither this Agreement nor the ISP convey
    or condition any right(s) to use any trademark, trade name, or service mark
    of Iridium or of INA. Any such right(s) shall only be conveyed and construed
    according to a separate written agreement.

Revised: 12/1/1997    Iridium Service Provider Agreement            Page 6 of 13
                      SkySite Communications Corporation
<PAGE>
 
9.  Relationship of Parties
    -----------------------

    A.  Both parties hereto agree that the relationship arising from the 
        appointment pursuant to this Agreement shall not constitute nor be
        construed as: (i) a principal/agent relationship, whether general,
        special or limited nature; (ii) a joint venture; (iii) a partnership;
        (iv) an employment relationship; or (v) a franchise. Both parties agree
        that neither party shall have any authority to incur any obligation on
        behalf of the other party.

    B.  Service Provider acknowledges and agrees that INA shall not be liable 
        to Service Provider, nor shall Service Provider make any claim against
        INA or Iridium, for injury, loss or damage sustained by reason of any
        unavailability, delay, faultiness (such as degradation of service) or
        failure of the facilities and services to be provided by INA or Iridium
        pursuant to or as a result of this agreement or for any injury, loss or
        damage sustained by the presence or use of the IRIDIUM Services or any
        ISU. Service Provider further agrees that it will include in each and
        any agreement to provide IRIDIUM Services an explicit commitment on the
        part of the Subscriber to waive any right to make any claim against
        Iridium or INA for injury, loss or damage sustained by reason of any
        unavailability, delay, faultiness or failure of the facilities and
        services to be provided by INA or Iridium or by reason of the presence
        or use of the IRIDIUM Services or any ISU.

    C.  SERVICE PROVIDER HEREBY AGREES THAT INA, IRIDIUM, AND ANY GATEWAY 
        OPERATOR SHALL NOT BE LIABLE FOR ANY CONSEQUENTIAL, SPECIAL, INDIRECT OR
        INCIDENTAL DAMAGES IN ANY WAY ARISING FROM THIS AGREEMENT. SERVICE
        PROVIDER ALSO HEREBY AGREES THAT THE TOTAL LIABILITY OF INA TO SERVICE
        PROVIDER FOR DAMAGES, LOSSES OR EXPENSES IN ANY WAY ARISING FROM THIS
        AGREEMENT SHALL NOT EXCEED AN AMOUNT EQUAL TO THE LAST THREE MONTHS OF
        PAYMENTS UNDER THIS AGREEMENT. Service Provider agrees that a similar
        provision will be included in its agreement with its subscribers.

    D.  Service Provider agrees to provide access to and usage of IRIDIUM 
        Services to subscribers only pursuant to a form of agreement to provide
        services which has been approved in writing by INA. Such form of
        agreement shall contain the substance of Article 9.B. and 9.C. above and
        any other provision specified in this Agreement. In particular, such
        form of agreement shall also contain the following provisions: (1) a
        provision that the subscribers shall comply with all applicable laws and
        regulations in its use of the IRIDIUM Services and (2) a provision that
        the subscribers shall not use or permit the use of IRIDIUM Services for
        foul or profane expressions or to impersonate another person with
        fraudulent or malicious

Revised: 12/1/1997        Iridium Service Provider Agreement        Page 7 of 13
                          SkySite Communications Corporation
<PAGE>
 
           intent or in such a way as to annoy, abuse, threaten or harass any
           person.
           

10.   Payment
      -------

      A.   Price. Service Provider shall pay INA for all IRIDIUM Services
           ----- 
           utilized and all related charges associated with such Services at
           rates specified in Exhibit B. Service Provider acknowledges that the
           rates specified in Exhibit B, are subject to change upon 30 days
           advance written notice from INA.

      B.   Billing/Method of Payment.  INA shall provide Service Provider with a
           -------------------------
           monthly invoice which invoice shall account for all sums due arising
           from the provision of IRIDIUM Services to Service Provider hereunder
           and Service Provider shall pay the full amount of such invoice by
           electronic funds transfer or by any other method which has been
           mutually agreed to by the parties in writing, within sixty days of
           receipt of such invoice.

      C.   Late Payment/Priority of Payments. Any amounts remaining unpaid after
           ---------------------------------          
           sixty days of receipt invoice shall be subjected to an additional
           late fee which shall be equivalent to 18% per annum of the overdue
           balance. All payments made by Service Provider shall be applied in
           the following priority: (i) late fees; (ii) overdue amounts and then;
           (iii) remaining balance.

      D.   Billing Disputes.  Service Provider shall notify INA of any disputed
           -----------------
           items within 60 days of receipt of invoice; notwithstanding the
           foregoing, Service Provider shall remain liable for all charges
           including disputed items.

11.   Fraud
      -----

      A.   Service Provider shall be responsible for all credit risk relating to
           its Subscribers and shall be liable for all charges arising from SIM
           use and all other ISU Equipment assigned to Service Provider pursuant
           to this Agreement, provided however, that INA shall at all times
           exercise its reasonable efforts, in accordance with applicable
           mandatory ISP's, to detect and inform Service Provider of any
           perceived fraudulent use of SIMS or ISU equipment assigned to Service
           Provider and to take appropriate steps to suspend or terminate any
           SIM or deactivate other ISU equipment involved in such perceived
           fraudulent use.

      B.   If Service Provider has exercised the ICRS Option in accordance with
           the terms of this Agreement, Service Provider shall be responsible
           for all credit risk relating to its ICRS Subscribers and shall be
           liable for all charges arising from SIM and/or MIN/ESN use and all
           other ISU equipment assigned to Service Provider pursuant to this
           Agreement; provided however, that INA shall at all times exercise its
           reasonable

    Revised: 12/1/1997      Iridium Service Provider Agreement      Page 8 of 13
                           SkySite Communications Corporation

<PAGE>
 
           efforts, in accordance with applicable mandatory ISP's, to detect and
           inform Service Provider of any perceived fraudulent use of SIMS and
           MIN/ESN pairs or ISU equipment assigned to Service Provider and shall
           suspend or terminate any SIM and MIN/ESN pairs or deactivate other
           ISU equipment involved in such perceived fraudulent use.

12.   No Assignment of Rights or Delegation of Obligations
      ----------------------------------------------------

      Service Provider shall not assign any of its rights or delegate any of its
      obligations hereunder to any Person without the prior written consent of
      INA, which will not be unreasonably withheld.

13.   Representations and Warranties
      ------------------------------

      A.   INA and Service Provider acknowledge that they have read this
           Agreement and understand and accept the terms, conditions and
           covenants contained herein.

      B.   Service Provider acknowledges that INA's ability to provide IRIDIUM
           Services is conditioned upon the grant of operating licenses by
           governmental authorities and the continuing validity of such
           licenses. Service Provider shall cooperate with and support the
           efforts of INA to obtain and maintain such licenses. INA makes no
           representation or warranty concerning such licenses and shall have no
           responsibility to Service Provider for any inability to provide
           IRIDIUM Services because of the failure to obtain or maintain, or
           invalidity of, such licenses at any time or from time to time.
       
      C.   Each party warrants that it has the necessary authority to lawfully
           enter into and perform its duties pursuant to this Agreement. Service
           Provider also warrants that it will comply with all applicable laws
           and regulations.

14.   Notices
      -------

      All notices and other communications provided for in this Agreement shall
      be in writing and shall be sufficiently given if made (i) by hand
      delivery, (ii) by reputable express courier service (charges prepaid) or
      (iii) by telecopier or (iv) by registered or certified mail (postage
      prepaid and return receipt requested) (a) if to INA, at the following
      address: 8440 South River Parkway, Tempe, Arizona 85284, or at such other
               ----------------------------------------------
      address as INA shall have furnished in writing to Service Provider and (b)
      if to Service Provider, at the following address: 11500 Sherman Way, North
                                                        ------------------------
      Hollywood, California 91605, or at such other address as Service Provider
      ---------------------------
      shall have furnished in writing to INA. All such notices and other
      communications shall be deemed to have been duly given: when delivered by
      hand, if personally delivered; five business days after being
      deposited with a reputable express courier service (charges prepaid);
      seven business days after

Revised: 12/1/1997        Iridium Service Provider Agreement    Page 9 of 13
                          SkySite Communications Corporation

<PAGE>
 
      being deposited in the mail, postage prepaid, if delivered by mail; and
      when receipt acknowledged (by a facsimile machine or otherwise), if
      telecopied.

15.   Confidential Information
      ------------------------

      A.   Each party agrees that, during and after the term of this Agreement,
           neither such party, its Affiliates, employees, agents, or Persons
           otherwise associated with such party, shall directly or indirectly,
           without the express prior written consent of the other party use,
           furnish, give away, reveal, divulge, make known, sell or transfer in
           any way Confidential Information of the other party, other than for
           the performance of duties hereunder.

      B.   Each party acknowledges that any Confidential Information that has
           been disclosed to it by the other party has been disclosed solely for
           the performance of its duties hereunder and such party agrees that
           all Confidential Information is the exclusive property of the
           disclosing party.

      C.   Each party agrees that if it is served with any form of legal process
           to obtain any Confidential Information, such party shall, if
           permitted by law, before taking any action, immediately notify the
           other party which shall, in addition to such party's efforts, if any,
           have the right to seek to quash such process, and such party agrees
           to take no action inconsistent with that of the other party.

16.   Termination
      -----------

      A.   Right to Terminate.
           ------------------

           Either party may terminate this Agreement at any time with immediate
           effect by giving notice to the other party if that party is in
           Default as defined in this Agreement. The termination of this
           Agreement shall have no effect on obligations which continue, or
           which are to be performed, after such termination.

      B.   Post Termination Obligations
           ----------------------------

           1.   Upon termination of this agreement, whether by exercise of the
                Right to Terminate or by expiration hereof without renewal,
                Service Provider shall promptly discontinue all use of
                advertising matter, slogans, trademarks, trade names or other
                marks identified with INA or Iridium LLC, shall immediately
                return to INA all procedures manuals and related materials
                provided to Service Provider, and shall not do business under
                INA or Iridium LLC names or any confusingly similar names or
                marks.

           2.   In consideration of the value of the specialized, technical
                knowledge of the IRIDIUM Service to be imparted by INA to

Revised: 12/1/1997       Iridium Service Provider Agreement   Page 10 of 13
                         SkySite Communications Corporation

<PAGE>
 
         Service Provider from time to time, Service Provider agrees that it's
         director and officer employees, key program employees or any of their
         immediate relatives, either alone or in any combination, for a period
         of two (2) years following the termination of this agreement for any
         reason, or for the remainder of the Initial Term, whichever is later,
         shall not directly or indirectly compete with INA in the satellite
         based mobile communication business, including but not limited to: (i)
         entering into any agreement or understanding or any employment, agency
         or other relationship with respect to any mobile satellite
         communication service; (ii) inducing, influencing or suggesting that
         any Subscriber or prospective Subscriber switch to another mobile
         satellite communication service or (iii) soliciting, enticing, hiring,
         employing or attempting to employ any employee or the agent or Reseller
         of INA or soliciting or entering into any agreement with any employee,
         other agent or Reseller of INA which interferes with or alters the
         employee's, other agent's or Reseller's relationship with INA. The
         geographical scope of this provision shall be co-extensive with the
         Service Area. Notwithstanding the foregoing, if this Agreement is
         terminated by virtue of non-renewal, the non-compete provisions
         specified above shall expire two (2) years after the advance written
         notice of intention not to renew and Subscriber list have been properly
         provided to INA as required elsewhere is this Agreement.

     3.  Service Provider shall promptly deliver to INA a list of all IRIDIUM 
         Subscribers then active or who have been active within the previous six
         (6) months, including the name and last known mailing address of each
         such Subscriber. In addition, when this Agreement will terminate by
         virtue of non-renewal, the list of all Subscribers as specified above
         shall be provided to INA within fifteen (15) days of the written notice
         of intention not to renew.

17.  Descriptive Headings
     --------------------

     The descriptive headings in this Agreement are inserted for convenience 
     only and do not constitute a part of this Agreement.

18.  Severability
     ------------

     Whenever possible, each provision of this Agreement shall be interpreted in
     such manner as to be effective and valid under applicable law, but if any
     provision of this Agreement is held to be prohibited by or invalid under
     applicable law, such provision shall be ineffective only to the extent of
     such prohibition or invalidity, without invalidating the remainder of this
     Agreement.

19.  Dispute Resolution/Arbitration
     ------------------------------

Revised: 12/1/1997       Iridium Service Provider Agreement        Page 11 of 13
                         SkySite Communications Corporation

<PAGE>
 
     A.  In the event of any dispute arising under this Agreement, including any
         allegation of breach and any failure to reach mutual agreement
         hereunder, the parties shall refer the matter for consideration and
         solution by the responsible executives of the parties. Either party may
         commence such proceedings by delivering to the other party a written
         request for such a meeting. Such request shall describe the dispute and
         identify the requesting party's responsible executive for purposes of
         resolving the dispute. The party receiving such a request shall have
         seven (7) calendar days to designate its responsible executive for the
         dispute in writing to the requesting party. The responsible executives
         shall meet within thirty (30) calendar days, at such time and place as
         may be mutually agreed to by the parties. The responsible executives
         shall use their reasonable efforts to resolve the dispute within
         fourteen (14) days following their meeting. If the responsible
         executives are unable to resolve the dispute they shall propose a
         mechanism for resolving the dispute. Such mechanism may include
         mediation or any other means of resolution. If the responsible
         executives are unable to agree on a mechanism for dispute resolution or
         if the agreed upon mechanism does not result in a binding decision
         within a reasonable time, the dispute shall be settled by arbitration
         pursuant to paragraph 19 (B) of this Agreement.

     B.  Any arbitration of disputes shall be conducted in Washington, D.C. in
         accordance with the Commercial Arbitration Rules of the American
         Arbitration Association.

     C.  The arbitration award shall be final and binding on the parties and
         shall be enforced in accordance with its terms. The arbitration fee
         shall be borne by the party as designated by the arbitration award. In
         the course of such arbitration, this Agreement shall be continuously
         performed except with respect to the part hereof which is the subject
         of, or which is directly and substantially affected by, the
         arbitration. In any such arbitration proceeding, any legal proceeding
         to enforce any arbitration award and any other legal action between the
         parties pursuant to or relating to this Agreement or the transactions
         contemplated hereby, both parties expressly waive the defense of
         sovereign immunity and any other defense based on the fact or
         allegation that it is an agency or instrumentality of a sovereign
         state. Any award of the arbitrators shall be enforceable by any court
         having jurisdiction over the party against whom the award has been
         rendered and such award shall be enforceable in accordance with the
         United Nations Convention on the Reciprocal Enforcement of Arbitral
         Awards (1958).

20.  Choice of Law
     -------------

     This Agreement shall be governed in accordance with the internal laws, 
without regard to conflict of laws principles, of the State of Arizona in the 
United States of America.

Revised: 12/1/1997    Iridium Service Provider Agreement           Page 12 of 13
                      SkySite Communications Corporation
<PAGE>
 
21.  Entire Agreement; Rights of Third Parties
     -----------------------------------------

     This Agreement and all the Exhibits hereto, including without limitation
     the Additional Terms and Conditions of Exhibit E, constitutes the entire
     agreement between the parties hereto and supersedes any understandings,
     agreements, or representations by or between such parties, written or oral,
     made at any time prior to the Commencement Date, that may relate in any way
     to the subject matter hereof. Without in any way limiting the generality of
     the foregoing, this Agreement supersedes all agreements, letters of intent
     and other written and oral agreements that may have been entered into by
     Service Provider and INA prior to the date hereof that relate in any way to
     the provision of IRIDIUM(R) Services. This Agreement is not intended to
     confer upon any Person other than the parties hereto any rights or remedies
     hereunder. In no event shall INA or Service Provider be liable for any
     delay or failure to perform its obligations hereunder due to any causes
     beyond its reasonable control. This agreement may not be modified except by
     a written agreement signed by the parties hereto.


Iridium U.S., L.P.                         SkySite Communications Corp.

Keith W. Bubb                              Philip A. Kernan, Jr.
-------------------------------------      -----------------------------
By:                                        By:

/s/ Keith W. Bubb                          /s/ Philip A. Kernan, Jr.
-------------------------------------      -----------------------------
Signature:                                 Signature:

Director, Gateway Business Operations      President & CFO
-------------------------------------      -----------------------------
Title:                                     Title:


                                           ICRS Option Acceptance

                                           -----------------------------
                                           By:

                                           -----------------------------
                                           Signature:

                                           -----------------------------
                                           Title:

Revised: 12/1/1997    Iridium Service Provider Agreement           Page 13 of 13
                      SkySite Communications Corporation
<PAGE>
 




                      IRIDIUM SERVICE PROVIDER AGREEMENT
                                  EXHIBIT E:

                        ADDITIONAL TERMS AND CONDITIONS


<PAGE>
 
                                   Exhibit E
                        Additional Terms and Conditions

     The following terms and conditions are made a part of the Iridium Service 
Provider Agreement between INA and   SkySite Communications Corporation
                                   -------------------------------------------
to which it is appended. When this Exhibit is signed by both parties, the terms 
hereof shall supersede and control over any provisions of the Iridium Service 
Provider Agreement that are inconsistent herewith.

     A.  Ethical Responsibilities of the Parties: INA and SkySite shall each 
         refrain from doing anything that would tend to discredit, dishonor,
         reflect adversely upon, or in any manner injure the reputation of the
         other or adversely affect the other, except that a party's enforcement
         of its rights and performance of its duties and obligation contained in
         this Agreement shall not be deemed a violation of the provisions of
         this paragraph. Each party shall be governed in all its dealings under
         this Agreement by the highest standards of honesty, integrity and fair
         dealing. Each party shall comply with all applicable federal, state and
         local laws ordinances and regulations in performing its duties and
         obligations contained in this Agreement.

     B.  Notwithstanding the provisions of Section 7, the initial term hereof 
         will continue for a period of three (3) years after execution of this
         Agreement.

     C.  This Agreement may be cancelled by SkySite Communications Corporation,
         without further obligation except for those obligations which are
         outlined in Article 16.B1, either (a) without cause, by providing
         written notice to INA, on or before February 1, 1998; or (b) if the
         Commencement Date does not occur before November 23, 1998.

IRIDIUM U.S., L.P.                            SERVICE PROVIDER

Keith W. Bubb                             Philip A. Kernan, Jr.
-------------------------------------     -------------------------------
By:                                       By:

/s/ Keith W. Bubb                         /s/ Philip A. Kernan, Jr.
-------------------------------------     -------------------------------
Signature:                                Signature:

Director, Gateway Business Operations     President & CFO
-------------------------------------     --------------------------------
Title:                                    Title:
<PAGE>
 
                                 ADDENDUM TWO
                  SATELLITE MINUTES COMMITMENT PLAN ADDENDUM

     This Satellite Minutes Commitment Plan (the "Plan") is dated as of 10 
                                                                        --
August, 1998 and is by and between Iridium U.S., L.P., d/b/a Iridium North 
------
America ("INA") and Project 77, Inc. ("Service Provider").
                    ----------------

                                   RECITALS

     Whereas, INA and Service Provider have entered into a service provider 
agreement, dated November, 1997 (the "Service Provider Agreement") to provide 
                 --------  ----
Iridium satellite services and the parties now desire to modify the pricing 
structure set forth therein;

     Whereas, Service Provider desires to obtain favorable pricing rates based 
upon outbound minutes of domestic and international Iridium homed satellite use 
purchased and paid for by Service Provider ("Satellite Minutes") specifically 
excluding any promotional or other free minutes of use and INA desires to obtain
a firm commitment from Service Provider for its Satellite Outbound Minutes over 
a fifteenth month period; and

     Whereas, INA and Service Provider desire to enter into this Plan upon the 
terms and conditions set forth herein.

                                   AGREEMENT

     Now, therefore, in consideration of the mutual agreements and 
understandings herein contained, the parties hereto agree as follows:

1.   Commitment Plan.  INA is offering a volume pricing plan based upon Service 
     ---------------
     Provider's level of commitment. The purpose of this Plan is to grant
     favorable pricing to Service Provider for cultivating additional Satellite
     Minutes through increased sales and Iridium subscribers. In addition, this
     Plan is designed to hold Service Provider accountable to its commitment and
     discouraging Service Provider from making unrealistic or impractical
     commitments, thereby gaining a market pricing advantage relative to other
     service providers.

2.   Commitment.  During the term of this Plan, Service Provider hereby agrees 
     ----------
     to commit to the (Initial One of the following):

           Entry Level Program and a minimum gross revenue of $500,000.00.
     -----

           Second Level Program and a minimum of 1,000,000 Satellite Minutes.
     -----

     /s/PM Third Level Program and a minimum of 3,000,000 Satellite Minutes.
     -----

Service Provider shall be entitled to the pricing and rebate structure and 
obligated to the assessment set forth below associated with the program selected
above.

8/7/98                  INA Proprietary & Confidential               Page 1 of 4
<PAGE>
 
Entry Level Program.
-------------------

     Pricing. Service Provider shall be charged the standard rates for 
Satellite Minutes (the "Standard Rate") which are contained in Exhibit B to the 
                                                               ---------
Service Provider Agreement.

     Commitment. Service Provider shall guaranty INA minimum gross revenue from 
Satellite Minutes equal to $500,000.00 during the term of this Plan.

     Assessment. If Service Provider fails to purchase at least $500,000.00 of 
Satellite Minutes, Service Provider shall pay to INA the difference between the 
gross revenue received from Service Provider for Satellite Minutes and 
$500,000.00 thirty days after the end of the term of this Plan.

     Termination. If Service Provider fails to purchase at least $500,000.00 of 
Satellite Minutes, INA shall have the option of terminating the Service Provider
Agreement, in its sole and absolute discretion.

Second Level Program.
--------------------

     Pricing. Service Provider shall be charged the Standard Rate of Satellite 
Minutes less a five percent (5%) discount. Once Service Provider reaches the 
first price breakpoint by purchasing 2,000,000 Satellite Minutes during the term
of this Plan, INA shall increase the applicable discount off of the Standard 
Rate to seven percent (7%) for Satellite Minutes purchased thereafter. Once 
Service Provider reaches the second price breakpoint by purchasing 3,000,000 
Satellite Minutes during the term of this Plan, INA shall increase the 
applicable discount off of the Standard Rate to ten percent (10%) for Satellite 
Minutes purchased thereafter.

     Commitment. Service Provider agrees to purchase a minimum of 1,000,000 
Satellite Minutes during the term of this Plan.

     Rebates. If Service Provider reaches the first price breakpoint by 
purchasing 2,000,000 Satellite Minutes during the term of this Plan, INA shall 
credit Service Provider with a rebate. The rebate shall be calculated by taking 
two percent (2%) of Service Provider's Blended Rate (defined below) and 
multiplying the product thereof by one million (1,000,000). If Service Provider 
purchases 3,000,000 Satellite Minutes during the term of this Plan, INA shall 
credit Service Provider with a second rebate. The second rebate shall be 
calculated by taking three percent (3%) of Service Provider's Blended Rate and 
multiplying the product thereof by one million (1,000,000).

     Assessment. If Service Provider's Satellite Minutes are less than 1,000,000
at the end of term of this Plan, Service Provider shall pay INA an assessment 
for each unused Satellite Minute within thirty days from the end of this Plan. 
The assessment shall be equal to the difference between 1,000,000 and Service 
Provider's Satellite Minutes multiplied by $1.00. For example, assume a Service 
Provider's Satellite Minutes are 800,000 at the end of this Plan. In this case 
the difference between the Service Provider's Satellite Minutes and its 
commitment is 200,000. Therefore, the Service Provider's assessment will be 
equal to $200,000.00 ([1,000,000 - 800,000] * $1.00).

8/7/98                 INA Proprietary & Confidential                Page 2 of 4
<PAGE>
 
Third Level Program.
--------------------

     Pricing.  Service Provider shall be charged the Standard Rates for 
Satellite Minutes less a ten percent (10%) discount. Once Service Provider 
reaches the first price breakpoint by purchasing 4,000,000 Satellite Minutes 
during the term of this Plan, INA shall increase the applicable discount off of 
the Standard Rate to twelve percent (12%) for Satellite Minutes purchased 
thereafter. Once Service Provider reaches the second price breakpoint by 
purchasing 5,000,000 Satellite Minutes during the term of this Plan, INA shall 
increase the applicable discount off of the Standard Rate to fifteen percent
(15%) for Satellite Minutes purchased thereafter.

     Commitment.  Service Provider agrees to purchase a minimum of 3,000,000 
Satellite Minutes during the term of this Plan.

     Rebate.  If Service Provider reaches the first price breakpoint by 
purchasing 4,000,000 Satellite Minutes during the term of this Plan, INA shall 
credit to Service Provider a rebate. The rebate shall be calculated by taking 
two percent (2%) of Service Provider's Blended Rate (defined below) and 
multiplying the product thereof by one million (1,000,000). If Service Provider 
reaches the second price breakpoint by purchasing 5,000,000 Satellite Minutes 
during the term of this Plan, INA shall credit to Service Provider a second 
rebate. The second rebate shall be calculated by taking three percent (3%) of 
Service Provider's Blended Rate and multiplying the product thereof by one 
million (1,000,000).

     Assessment.  If Service Provider's Satellite Minutes are less than 
3,000,000 at the end of the term of this Plan, Service Provider shall pay INA an
assessment for each unused Satellite Minute thirty days from the end of this 
Plan. The assessment shall be equal to the difference between 3,000,000 and 
Service Provider's Satellite Minutes multiplied by $1.00.

3.   Evaluation.  INA shall evaluate Service Provider's performance six months
     ----------
     from the Commencement Date and thereafter on a quarterly basis. If, in
     INA's sole and absolute discretion, INA determines that Service Provider
     will not be able to meet its commitment obligations contained herein, INA
     reserves the right to reduce or eliminate the pricing discount granted to
     Service Provider to recover the assessment described above. INA's decision
     not to modify the discount applied shall not effect Service Provider's
     commitment or the assessment due for failure to meet its commitment.

4.   Rebate Calculation.  Service Provider's Blended Rate shall be equal to the
     ------------------
     weighted average of the Standard Rate for Satellite Minutes during the
     applicable period. The "applicable period" shall mean the period between
     the billing cycle immediately following Service Provider's Satellite
     Minutes exceeding the prior price breakpoint and the billing cycle
     immediately following Service Provider's Satellite Minutes exceeding the
     current price breakpoint. Service Provider shall, within thirty (30) days
     of a written request therefor, reimburse INA for the full amount of any
     rebate credited hereunder which should not have been credited to Service
     Provider as the result of any re-calculation, for any reason, of the total
     amount of Service Provider's Satellite Minutes. INA shall apply a rebate or
     reimbursement of a rebate to Service Provider's invoice for the billing
     cycle following of the close of the billing cycle in which the commitment
     is exceeded or the recalculation is made.

5.   Term.  This Plan shall be effective for fifteen (15) months from the
     ----
     Commencement Date or December 31, 1999 whichever is later. If the Service
     Provider Agreement is

8/7/98                  INA Proprietary & Confidential               Page 3 of 4
<PAGE>
 
    terminated prior to such date, this Plan shall terminate and Service
    Provider shall pay to INA the assessment calculated above using Service
    Provider's actual performance through the billing cycle immediately
    following the termination date and a minimum forecast analysis prepared by
    INA, in its sole and absolute discretion, for such time period. The
    assessment shall be paid thirty (30) days after the end of the billing cycle
    following the termination date.

6.  Revisions. Upon thirty days written notice to Service Provider, INA reserves
    ---------
    the right to revise the terms of this Plan in its sole and absolute
    discretion depending on market conditions during the term of this Plan. If
    there is a cumulative pricing increase of five percent (5%) or more during
    any six months period, Service Provider shall have the option to revise its
    commitment election; provided, however, Service Provider shall not be
    entitled to revise its election if it could not reasonably expect to meet
    its commitment had the pricing increase not occurred.

7.  Amendment. Unless otherwise modified herein, the terms and conditions set
    ---------
    forth in the Service Provider Agreement shall remain in full force and
    effect. All capitalized terms not defined herein shall have the meaning
    assigned in the Service Provider Agreement.

Dated effective as of the date first written above.

Iridium U.S., L.P.                           Project 77, Inc.
                                             -------------------------------

By: /s/ Jim Walz                             By: /s/ Philip A. Kernan, Jr.
   -----------------------------                ----------------------------
     Jim Walz

Title: President                             Title: President





8/7/98                  INA Proprietary & Confidential               Page 4 of 4
<PAGE>
 
                           AMENDMENT TO ADDENDUM TWO
                  SATELLITE MINUTES COMMITMENT PLAN ADDENDUM

     The following terms and conditions are made a part of Addendum Two to the 
Iridium Service Provider Agreement between INA and Service Provider, to which it
is appended. When this Amendment is signed by both parties, the terms hereof 
shall supersede and control over any provisions of Addendum Two that are 
inconsistent herewith.

A.  Section 3, Evaluation. Section 3 is deleted in its entirety and replaced 
               -----------
with the following:

"3. Evaluation.  INA shall evaluate Service Provider's performance six months 
 -------------
from the Commencement Date and thereafter on a quarterly basis. The initial six 
month's performance review will be undertaken for all service providers as a 
group, and if a substantial majority of service providers have been unable to 
meet their program commitment levels, INA, at its sole and absolute discretion, 
may make reasonable and non-discriminatory adjustments to the rates and 
commitment levels applicable to service providers, including Service Provider. A
decision by INA not to modify the Program Level applied shall leave in effect 
Service Provider's commitment and the assessment due for failure to meet its 
commitment.

If during the initial six month's performance review, in INA's sole and absolute
discretion, INA determines that a general adjustment of rates and commitment 
levels is unnecessary but that Service Provider has not reached 300,000 
Satellite Minutes, INA shall adjust Service Provider's commitment to a lower 
level Program hereunder. INA shall have sole and absolute discretion as to which
lower level Program hereunder Service Provider's commitment will be adjusted. In
the case of such Program adjustment, Service Provider shall reimburse, as set 
forth in  Section 4 below, INA five percent (5%) of all Service Provider's 
actual charges incurred under this Agreement as of the date of such Program 
adjustment ("Recapture of Discount")."

B.  Section 4. Rebate Calculation. Section 4 is amended to add the following:
               ------------------

"The process provided herein shall apply to Rental Service Provider's payment of
the Recapture of Discount calculated pursuant to Section 3."

Created on 08/08/98 12:33 PM    INA Proprietary & Confidential       Page 1 of 2