<Page>

                                                                  EXECUTION COPY




                           SIRIUS SATELLITE RADIO INC.
                            (A Delaware corporation)

                        75,000,000 Shares of Common Stock

                                 TERMS AGREEMENT
                                 ---------------

                                                                  June 4, 2003

To:      Sirius Satellite Radio Inc.
         1221 Avenue of the Americas, 36th Floor
         New York, New York 10020

Ladies and Gentlemen:

                  This is a Terms Agreement referenced in the Form Underwriting
Agreement filed on January 3, 2002 on Form 8-K as Exhibit 1.1 to Registration
Statement No. 333-64344. The terms of the Form Underwriting Agreement are hereby
incorporated herein. We understand that Sirius Satellite Radio Inc., a Delaware
corporation (the "Company"), proposes to issue and sell 75,000,000 shares of its
Common Stock, par value $.001 per share (the "Underwritten Securities"). Subject
to the terms and conditions set forth or incorporated by reference herein,
Morgan Stanley & Co. Incorporated and UBS Warburg LLC (the "Underwriters")
severally and not jointly offer to purchase the number of Underwritten
Securities opposite their names set forth below at the purchase price set forth
below, and some or all of the Option Underwritten Securities set forth below, to
the extent any Underwritten Securities or Option Underwritten Securities are
purchased in accordance with the terms hereof.







<Page>




                                                                               2




                                                                   Number of
Underwriter                                                 Underwritten Securities
- -----------                                                 -----------------------
                                                                
Morgan Stanley & Co. Incorporated....................              60,000,000
UBS Warburg LLC......................................              15,000,000



         The Underwritten Securities shall have the following terms:

                                                             Common Stock
                                                             ------------


                                     
Title:                                  Common Stock, par value $.001 per share.

Number of Shares                        75,000,000

Number of Option Underwritten           The Underwriters have an option to purchase up to an additional
Securities:                             11,250,000 shares of Underwritten Securities (the "Option
                                        Underwritten Securities") at the public offering price, less an
                                        underwriting discount, within 30 days from the Closing Date to
                                        cover over-allotments.

Initial public offering price:          $1.80 per share.

Purchase price:                         $1.6875 per share.

Selling concession:                     $0.07 per share.

Listing requirements:                   Nasdaq National Market

Lock-up provisions:                     For a period of 180 days from the date of this Terms Agreement, the
                                        Company and certain of its executive officers will not, without the
                                        prior written consent of Morgan Stanley & Co. Incorporated, (1)
                                        offer, pledge, sell, contract to sell, sell any option or contract
                                        to purchase, purchase any option or contract to sell, grant any
                                        option, right or warrant to purchase, lend, or otherwise transfer
                                        or dispose of, directly or indirectly, any shares of common stock
                                        or any securities convertible into or exercisable or exchangeable
                                        for common stock or (2) enter into any swap or other arrangement
                                        that transfers to another, in whole or in part, any of the economic
                                        consequences of ownership of the common stock, whether any such
                                        transaction described in clause (1) or (2) above is to be settled
                                        by delivery of common stock or such other securities, in cash or
                                        otherwise. The foregoing sentence shall not apply to (a) the sale
                                        of any Underwritten Securities to the Underwriters pursuant to







<Page>




                                                                               3



                                     
                                        the Form Underwriting Agreement and this Terms Agreement, (b)
                                        transactions relating to shares of common stock or other
                                        securities acquired in open market transactions after the
                                        completion of the Public Offering or (c) the issuance by the
                                        Company of additional options under the Company's existing stock
                                        option plans, provided that such options are not exercisable
                                        during the 180-day period. In addition, without the prior written
                                        consent of Morgan Stanley & Co. Incorporated on behalf of the
                                        Underwriters, none of such officers will, during the period
                                        commencing on the date hereof and ending on December 1, 2003, make
                                        any demand for or exercise any right with respect to, the
                                        registration of any shares of common stock or any security
                                        convertible into or exercisable or exchangeable for common stock.
                                        Such officers will also agree and consent to the entry of stop
                                        transfer instructions with the Company's transfer agent and
                                        registrar against the transfer of such officers' shares of common
                                        stock except in compliance with the foregoing restrictions.

                                        For a period of 30 days from the date of this Terms Agreement,
                                        Apollo Investment Fund IV, L.P. and Apollo Overseas Partners IV,
                                        L.P., stockholders of the Company, will agree to not, without the
                                        prior written consent of Morgan Stanley & Co. Incorporated, (1)
                                        offer, pledge, sell, contract to sell, sell any option or contract
                                        to purchase, purchase any option or contract to sell, grant any
                                        option, right or warrant to purchase, lend, or otherwise transfer
                                        or dispose of, directly or indirectly, any shares of common stock
                                        or any securities convertible into or exercisable or exchangeable
                                        for common stock or (2) enter into any swap or other arrangement
                                        that transfers to another, in whole or in part, any of the
                                        economic consequences of ownership of the common stock, whether
                                        any such transaction described in clause (1) or (2) above is to be
                                        settled by delivery of common stock or such other securities, in
                                        cash or otherwise. The foregoing sentence shall not apply to
                                        transactions relating to shares of common stock or other
                                        securities acquired in open market transactions after the
                                        completion of the Public Offering. In addition, without the prior
                                        written consent of Morgan Stanley & Co. Incorporated on behalf of
                                        the Underwriters, none of such stockholders will, during the
                                        period commencing on the date hereof and ending on July 4, 2003,
                                        make any demand for or







<Page>


                                                                               4



                                     
                                        exercise any right with respect to, the registration of any shares
                                        of common stock or any security convertible into or exercisable or
                                        exchangeable for common stock. Such stockholders will also agree
                                        and consent to the entry of stop transfer instructions with the
                                        Company's transfer agent and registrar against the transfer of
                                        such stockholders' shares of common stock except in compliance
                                        with the foregoing restrictions.


Comfort Letter:                         The Company shall cause the Accountant's Comfort Letter and the
                                        Bring-down Comfort Letter referenced in, respectively Section 5(g)
                                        and Section 5(h) of the Form Underwriting Agreement to be
                                        delivered, except that such letters will be delivered by Ernst &
                                        Young LLP in lieu of Arthur Andersen LLP.


Additional Representations of the       The Company represents and warrants to and agrees with each of the
Company:                                Underwriters that there are no contracts, agreements or
                                        understandings between the Company and any person granting such
                                        person the right to require the Company to file a registration
                                        statement under the Securities Act with respect to any securities
                                        of the Company or to require the Company to include such
                                        securities with the Underwritten Securities registered pursuant to
                                        the Registration Statement.

Additional Covenants of the Company:    The Company covenants with each of the Underwriters whether or not
                                        the transactions contemplated in this Agreement are consummated or
                                        this Agreement is terminated, to pay or cause to be paid all
                                        expenses incident to the performance of its obligations under this
                                        Agreement, including: (i) the cost of printing or producing any
                                        Blue Sky or Legal Investment memorandum in connection with the
                                        offer and sale of the Underwritten Securities under state
                                        securities laws and all expenses in connection with the
                                        qualification of the Securities for offer and sale under state
                                        securities laws as provided in Section 3(f) of the Form
                                        Underwriting Agreement, including filing fees and the reasonable
                                        fees and disbursements of counsel for the Underwriters in
                                        connection with such qualification and in connection with the Blue
                                        Sky or Legal Investment memorandum, (ii) the cost of printing
                                        certificates representing the Underwritten Securities, (iii) the
                                        costs and charges of any transfer agent, registrar or depositary,
                                        (iv) the document production charges and expenses associated with
                                        printing








<Page>




                                                                               5


                                     
                                        this Agreement and (v) all other costs and expenses incident to
                                        the performance of the obligations of the Company hereunder for
                                        which provision is not otherwise made in this Section. It is
                                        understood, however, that except as provided in Sections 4, 6 and
                                        7 of the Form Underwriting Agreement, "Additional Covenants of the
                                        Company" and "Additional Termination Provisions" below, the
                                        Underwriters will pay all of their costs and expenses, including
                                        fees and disbursements of their counsel, stock transfer taxes
                                        payable on resale of any of the Underwritten Securities by them
                                        and any advertising expenses connected with any offers they may
                                        make.

Additional Conditions of                The obligations of the Underwriters to purchase and pay for the
Underwriters' Obligations:              Underwritten Securities pursuant this Terms Agreement are subject
                                        to the following further conditions: subsequent to execution and
                                        delivery of this Terms Agreement and prior to the Closing Date
                                        there shall not have occurred any change, or any development
                                        involving a prospective change, in the condition, financial or
                                        otherwise, or in the earnings, business or operations of the
                                        Company and its subsidiaries, taken as a whole, from that set
                                        forth in the Prospectus (exclusive of any amendments or
                                        supplements thereto subsequent to the date of this Agreement)
                                        that, in Morgan Stanley & Co. Incorporated's judgment, is material
                                        and adverse and that makes it, in Morgan Stanley & Co.
                                        Incorporated's judgment, impracticable to market the Underwritten
                                        Securities on the terms and in the manner contemplated in the
                                        Prospectus.

Additional Termination Provisions:      The Underwriters may terminate this Terms Agreement, by notice to
                                        the Company at any time at or prior to the Closing Date if (i) trading
                                        is suspended or materially limited on, or by, as the case may be, any
                                        of the Chicago Board of Options Exchange, the Chicago Mercantile
                                        Exchange or the Chicago Board of Trade, (ii) a material disruption
                                        in securities settlement, payment or clearance services in the
                                        United States shall have occurred, or (iii) there shall have
                                        occurred any outbreak or escalation of hostilities, or any change
                                        in financial markets or any calamity or crisis that, in Morgan
                                        Stanley & Co. Incorporated's judgment, is material and adverse and
                                        which, singly or together with any other event specified in this
                                        clause (iii), makes it, in Morgan Stanley & Co. Incorporated's
                                        judgment, impracticable or inadvisable to









<Page>




                                                                               6


                                     
                                        proceed with the offer, sale or delivery of the Underwritten
                                        Securities on the terms and in the manner contemplated in the
                                        Prospectus.

                                        If this Terms Agreement shall be terminated by any Underwriters,
                                        or any of them because of any failure or refusal on the part of
                                        the Company to comply with the terms or to fulfill any of the
                                        conditions of this Terms Agreement, or if for any reason the
                                        Company shall be unable to perform its obligations under this
                                        Terms Agreement, the Company will reimburse the Underwriters or
                                        such Underwriters as have so terminated this Terms Agreement with
                                        respect to themselves, severally, for all out-of-pocket expenses
                                        (including the fees and disbursements of their counsel) reasonably
                                        incurred by such Underwriters in connection with this Terms
                                        Agreement or the offering contemplated hereunder.


Additional Indemnification Provisions:  The Company agrees to indemnify and hold harmless each affiliate
                                        of an Underwriter within the meaning of Rule 405 under the 1933
                                        Act.

Other Terms:

                                        This Terms Agreement may be signed in counterparts, each of which
                                        shall be an original, with the same effect as if the signatures
                                        thereto and hereto were upon the same instrument.

Notices:                                All notices and other communications hereunder shall be in writing
                                        and shall be deemed to have been duly given if mailed or
                                        transmitted by any standard form of telecommunication. Notices to
                                        the Underwriters shall be directed to Morgan Stanley & Co.
                                        Incorporated, 1585 Broadway, New York, NY 10036, Attention: Global
                                        Capital Markets Syndicate Desk; notices to the Company shall be
                                        directed to the Company at 1221 Avenue of the Americas, 36th
                                        Floor, New York, New York 10020, Attention: Patrick L. Donnelly,
                                        Executive Vice President, General Counsel and Secretary.

Closing Date and location:              June 10, 2003
                                        10:00 a.m.
                                        Cravath, Swaine & Moore LLP
                                        Worldwide Plaza
                                        825 Eighth Avenue
                                        New York, NY 10019-7475









<Page>



                                                                               7


                  Please accept this offer by signing a copy of this Terms
Agreement in the space set forth below and returning the signed copy to us.

                                       Very truly yours,

                                       MORGAN STANLEY & CO. INCORPORATED

                                       UBS WARBURG LLC,

                                       by  MORGAN STANLEY & CO. INCORPORATED


                                       -----------------------------------------
                                       James C. Murray
                                       Vice President


Accepted:

SIRIUS SATELLITE RADIO INC.,

     by

           --------------------------------------------------
           Patrick L. Donnelly
           Executive Vice President,
           General Counsel and Secretary