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                                                                     EXHIBIT 4.5

     THIS SUPPLEMENTAL INDENTURE NO. 1 dated as of December   , 2001 (the
"Supplemental Indenture") among Loral Cyberstar, Inc., (formerly) Orion Network
Systems, Inc., a Delaware corporation, as Issuer, (the "Issuer"), the Subsidiary
Guarantors party hereto, and Bankers Trust Company, a New York banking
corporation, as trustee under the indenture referred to below (the "Trustee") to
the Indenture dated as of January 31, 1997 (the "Original Indenture").

                              W I T N E S S E T H:

     WHEREAS, there has previously been executed and delivered to the Trustee an
Indenture providing for the issuance of the Issuer's 12 1/2% Senior Discount
Notes due 2007 (the "Notes");

     WHEREAS, the Issuer has solicited consents from the Holders of certain
amendments (the "Amendments") to the Indenture; and

     WHEREAS, the Holders of a majority in aggregate principal amount of the
outstanding Notes have consented to the Amendments in accordance with the
provisions of Section 9.02 of the Indenture.

     NOW, THEREFORE, in consideration of the foregoing and of the mutual
premises and covenants contained herein and for other good and valuable
consideration, the parties hereto agree, for the equal and proportionate benefit
of the respective Holders from time to time of the Notes, as follows:

                                  ARTICLE ONE

                           AMENDMENT OF THE INDENTURE

     SECTION 1.01.  AMENDMENTS TO THE INDENTURE.

     Sections 4.02, 4.03, 4.04, 4.05, 4.06, 4.07, 4.08, 4.09, 4.10, 4.12, 4.13,
4.14, 4.15, 4.18, 4.19, 5.01, 5.02, 6.01 and 6.02 of the Indenture and the
penultimate paragraph of Section 10.01 of the Indenture are amended and restated
in their entirety to read as set forth on Schedule 1 hereto.

                                  ARTICLE TWO

                                 MISCELLANEOUS

     SECTION 2.01.  EFFECT.  The provisions set forth in this Supplemental
Indenture shall be deemed to be, and shall be construed as part of, the
Indenture to the same extent as if set forth fully therein. All references to
the Indenture in the Indenture or in any other agreement, document or instrument
delivered in connection therewith or pursuant thereto shall be deemed to refer
to the Indenture as amended by this Supplemental Indenture. Except as amended
hereby, the Indenture shall remain in full force and effect.

     SECTION 2.02.  TRUST INDENTURE ACT CONTROLS.  If any provision of this
Supplemental Indenture limits, qualifies or conflicts with another provision
that is required by or deemed to be included in this Supplemental Indenture by
the Trust Indenture Act (as such term is defined in the Indenture), the required
or incorporated provision shall control.

     SECTION 2.03.  GOVERNING LAW.  THIS SUPPLEMENTAL INDENTURE SHALL BE
GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK
(WITHOUT GIVING EFFECT TO THE CONFLICT OF LAWS PRINCIPLES THEREOF).

     SECTION 2.04.  COUNTERPARTS.  This Supplemental Indenture may be executed
in any number of counterparts, each of which shall be original, but such
counterparts shall together constitute but one and the same instrument.
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     SECTION 2.05.  EFFECTIVENESS.  This Supplemental Indenture shall not be
effective until the time that is the later of (x) time this Supplemental
Indenture is executed and delivered by the Trustee and (7) the moment
immediately prior to the original issuance of the Issuer's 10% Senior Notes due
2006.

     SECTION 2.06.  SEVERABILITY.  In case any provision in this Supplemental
Indenture shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

     SECTION 2.07.  EFFECT OF HEADINGS.  The Article and Section headings herein
are for convenience only and shall not affect the construction hereof.

     IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed as of the day and year first above written.

                                          LORAL CYBERSTAR, INC.
                                          (formerly) ORION NETWORKS SYSTEMS,
                                          INC., ORION SATELLITE CORPORATION and
                                          ORION OLDCO SERVICES

                                          By:
                                            ------------------------------------
                                              Name:
                                              Title:

                                          [LORAL CYBERSTAR GLOBAL SERVICES,
                                          INC.](formerly) ORION ATLANTIC EUROPE,
                                          INC., ORION ASIA PACIFIC CORPORATION
                                          and ASIA PACIFIC SPACE &
                                          COMMUNICATIONS, LTD.

                                          By:
                                            ------------------------------------
                                              Name:
                                              Title:

                                          ORIONNET, INC.
                                          (formerly) ORIONNET FINANCE
                                          CORPORATION

                                          By:
                                            ------------------------------------
                                              Name:
                                              Title:

                                          [            ]
                                          (formerly) INTERNATIONAL PRIVATE
                                          SATELLITE PARTNERS, L.P.

                                          By:
                                            ------------------------------------
                                              Name:
                                              Title:

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                                          BANKERS TRUST COMPANY, AS TRUSTEE

                                          By:
                                            ------------------------------------
                                              Name:
                                              Title:

                                        3
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                   SCHEDULE 1 TO SUPPLEMENTAL INDENTURE NO. 1

                          AMENDMENTS TO THE INDENTURE

     SECTION 4.02.  Intentionally omitted.

     SECTION 4.03.  Intentionally omitted.

     SECTION 4.04.  Intentionally omitted.

     SECTION 4.05.  Intentionally omitted.

     SECTION 4.06.  Intentionally omitted.

     SECTION 4.07.  Intentionally omitted.

     SECTION 4.08.  Intentionally omitted.

     SECTION 4.09.  Intentionally omitted.

     SECTION 4.10.  Intentionally omitted.

     SECTION 4.12.  Intentionally omitted.

     SECTION 4.13.  Intentionally omitted.

     SECTION 4.14.  Intentionally omitted.

     SECTION 4.15.  Intentionally omitted.

     SECTION 4.18.  Intentionally omitted.

     SECTION 4.19.  Intentionally omitted.

     SECTION 5.01.  CONSOLIDATION, MERGER AND SALE OF ASSETS.  Each of the
Company and each Guarantor will not consolidate with, merge with or into, or
sell, convey, transfer, lease or otherwise dispose of all or substantially all
of its property and assets (as an entirety or substantially an entirety in one
transaction or a series of related transactions), to, any Person or permit any
Person to merge with or into the Company or any Guarantor unless:

          (i) the Company or any Guarantor, as the case may be, shall be the
     continuing Person, or the Person (if other than the Company or Guarantor)
     formed by such consolidation or into which the Company or any Guarantor, as
     the case may be, is merged or that acquired or leased such property and
     assets of the Company or as any Guarantor, as the case may be, shall be a
     corporation organized and validly existing under the laws of the United
     States of America or any jurisdiction thereof and shall expressly assume,
     by a supplemental indenture, executed and delivered to the Trustees, all of
     the obligations of the Company or any Guarantor, as the case may be, on all
     of the Notes and under the Indenture;

          (ii) Intentionally omitted;

          (iii) Intentionally omitted;

          (iv) Intentionally omitted; or

          (v) the Company or Guarantor, as the case may be, delivers to the
     Trustee an Officers' certificate and an Opinion of Counsel, in each case
     stating that such consolidation, merger or transfer and such supplemental
     indenture complies with this provision and that all conditions precedent
     provided for herein relating to such transaction have been complied with.

     SECTION 5.02.  SUCCESSOR SUBSTITUTED.  Upon any consolidation or merger, or
any sale, conveyance, transfer or other disposition of all of substantially all
of the property and assets of the Company or any Guarantor, as the case may be,
in accordance with Section 5.01 of this Indenture, the successor Person formed
by such consolidation or into which the Company or such Guarantor is merged or
to which such
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sale, conveyance, transfer or other disposition is made shall succeed to, and be
substituted for, and may exercise every right and power of, the Company or such
Guarantor under this Indenture with the same effect as if such successor Person
had been named as the Company or such Guarantor herein and thereafter, except in
the case of a lease, the predecessor Person shall be relieved of all obligations
and covenants under this Indenture and the Notes.

     SECTION 6.01.  EVENTS OF DEFAULT.  An "Event of Default" shall occur with
respect to the Notes if:

          (a) the Company defaults in the payment of principal of (or premium,
     if any, on) any Note when the same becomes due and payable at maturity,
     upon acceleration, redemption or otherwise;

          (b) the Company defaults in the payment of interest on any Note when
     the same becomes due and payable, and such default continues for a period
     of 30 days;

          (c) Intentionally omitted;

          (d) the Company defaults in the performance of or breaches any other
     covenant or agreement of the Company in this Indenture or under the Notes
     (other than a default specified in clause (a) or (b) above) and such
     default or breach continues for a period of 30 consecutive days after
     written notice by the Trustee or the Holders of 25% or more in aggregate
     principal amount at maturity of the Notes;

          (e) Intentionally omitted;

          (f) Intentionally omitted;

          (g) Intentionally omitted;

          (h) Intentionally omitted;

          (i) the Note Guarantee shall cease to be, or shall be asserted in
     writing by the Company or any Guarantor not to be, in full force and effect
     or enforceable in accordance with their respective terms; or

          (j) Intentionally omitted.

     SECTION 6.02  ACCELERATION.  If an Event of Default occurs and is
continuing under the Indenture, the Trustee of the Holders of at least 25% in
aggregate principal amount at maturity of the Notes then outstanding, by written
notice to the Company (and to the Trustee if such notice is given by the
Holders), may, and the Trustee at the request of such Holders shall, declare the
Accreted Value of, premium, if any, and accrued interest on the Notes to be
immediately due and payable. Upon a declaration of acceleration, such Accreted
Value of, premium, if any, and accrued interest shall be immediately due and
payable.

     The penultimate of Section 10.01 is amended and restated in its entirety to
read as follows:

     Each Guarantor hereby irrevocably defers, until the principal of, premium,
if any, and interest on the Notes shall have been paid in full, any claim or
other rights which it may now or hereafter acquire against the Company that
arise from the existence, payment, performance or enforcement of its obligations
under its Guarantee and this Indenture, including, without limitation, any right
of subrogation, reimbursement, exoneration, contribution, indemnification, any
right to participate in any claim or remedy of the Holders against the Company
or any collateral which any such Holder or the Trustee on behalf of such Holder
hereafter acquires, whether or not such claim, remedy or right arises in equity,
or under contract, statute or common law, including, without limitation, the
right to take or receive from the Company, directly or indirectly, in cash or
other property or by set-off of in any other manner, payment or security on
account of such claim or other rights, except (a) each Transferred Guarantor
shall not be subject to the foregoing limitations and (b) the Company and the
Guarantors (other than Transferred Guarantors) shall, at the request of any
Transferred Guarantor, indemnify such Transferred Guarantor for any amount
(including guarantee payments) or expense incurred by such Transferred Guarantor
under its Guarantee. If any amount shall be paid to any Guarantor (other than a
Transferred Guarantor) in violation of the preceding sentence and the principal
of, premium, if any, and accrued interests on the Notes shall not have been paid
in full, such amount shall be deemed to have been paid to such Guarantor for the
benefit of, and held

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in trust for the benefit of, the Holders, and shall forthwith be paid to the
Trustee for the benefit of the Holders to be credited and applied upon the
principal of, premium, if any, and accrued interest on the Notes. Each Guarantor
acknowledges that it will receive direct and indirect benefits from the issuance
of the Notes pursuant to this Indenture and that the waivers set forth in this
Section 10.01 are knowingly made in contemplation of such benefits. As used
herein, the term "Transferred Guarantor" refers to any Guarantor engaged in the
data business the stock of which (or the stock of any direct or indirect owner
of such stock) is transferred to a Person other than the Company or another
Guarantor.

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