Exhibit 4.21

     THIS WARRANT AND ANY SECURITIES ACQUIRED UPON THE EXERCISE OF THIS WARRANT
HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
"SECURITIES ACT"), OR ANY STATE SECURITIES LAWS AND NEITHER THIS WARRANT NOR
SUCH SECURITIES NOR ANY INTEREST THEREIN MAY BE OFFERED, SOLD, TRANSFERRED,
PLEDGED OR OTHERWISE DISPOSED OF EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION
STATEMENT UNDER SUCH ACT OR SUCH LAWS OR AN EXEMPTION FROM REGISTRATION UNDER
SUCH ACT AND SUCH LAWS.

                           SIRIUS SATELLITE RADIO INC.

                     SERIES B COMMON STOCK PURCHASE WARRANT

     This certifies that, for good and valuable consideration, the receipt and
adequacy of which is hereby acknowledged, Sirius Satellite Radio Inc., a
Delaware corporation (the "Company"), grants to _______________________, or its
assigns (the "Warrantholder"), the right to subscribe for and purchase from the
Company an aggregate of ____________ validly issued, fully paid and
nonassessable shares (the "Warrant Shares") of the Company's common stock, par
value $0.001 per share (the "Common Stock"), at the purchase price per share of
$0.92 (such purchase price per share, the "Exercise Price"), at any time and
from time to time, during the period from and including 9:00 AM, New York City
time, on the date hereof until 5:00 PM, New York City time, on March 7, 2005
(the "Expiration Date"), all subject to the terms, conditions and adjustments
herein set forth.

     Certain capitalized terms used herein and not otherwise defined shall have
the meanings ascribed to them in Section 10.

Certificate No. ____

Number of Shares: ___________

Name of Warrantholder: _____________________

     Section 1. Duration and Exercise of Warrant; Limitations on Exercise;
Payment of Taxes.

     1.1 Exercisability of Warrant. Subject to the terms and conditions set
forth herein, this Warrant is immediately exercisable. The Company shall not,
prior to the Expiration Date, take any action which would have the effect of
preventing or disabling the Company from delivering the Warrant Shares to the
Warrantholder upon exercise of this Warrant or otherwise performing the
Company's obligations under this Warrant.

     1.2 Duration and Exercise of Warrant. Subject to the terms and conditions
set forth herein, this Warrant may be exercised, in whole or in part, by the
Warrantholder by:

          (a) the surrender of this Warrant to the Company, with a duly executed
     Exercise Form specifying the number of Warrant Shares to be purchased,
     during normal business hours on any Business Day prior to and including the
     Expiration Date; and






                                                                               2


          (b) the delivery of payment to the Company, for the account of the
     Company, by cash, by certified or bank cashier's check or by wire transfer
     of immediately available funds in accordance with wire instructions that
     shall be provided by the Company upon request, of the Exercise Price for
     the number of Warrant Shares specified in the Exercise Form in lawful money
     of the United States of America.

     In the alternative, the Warrantholder may exercise its right, on any
Business Day prior to and including the Expiration Date, to receive Warrant
Shares on a net basis, such that, without the exchange of any funds, the
Warrantholder receives that number of Warrant Shares otherwise issuable upon
exercise of this Warrant less that number of Warrant Shares having an aggregate
fair market value (as determined by the Board of Directors) at the time of
exercise equal to the aggregate Exercise Price that would otherwise have been
paid in respect of this Warrant by the Warrantholder.

     The Company agrees that such Warrant Shares shall be deemed to be issued to
the Warrantholder as the record holder of such Warrant Shares as of the close of
business on the date on which this Warrant shall have been surrendered and
payment made for the Warrant Shares as aforesaid.

     1.3 Limitations on Exercise. Notwithstanding anything to the contrary
herein, the obligation to deliver Warrant Shares upon the exercise of this
Warrant shall be subject to the conditions that no preliminary or permanent
injunction or other order, decree or ruling issued by a court of competent
jurisdiction or by a governmental, regulatory or administrative agency or
commission, shall be in effect which would prohibit such sale and delivery, and
any applicable waiting period under the HSR Act shall have expired or been
terminated.

     1.4 Warrant Shares Certificate. A duly issued stock certificate or
certificates for the Warrant Shares specified in the Exercise Form shall be
delivered to the Warrantholder within five Business Days after receipt by the
Company of the Exercise Form and receipt of payment of the purchase price. If
this Warrant shall have been exercised only in part, the Company shall, at the
time of delivery of the stock certificate, deliver to the Warrantholder a new
Warrant evidencing the rights to purchase the remaining Warrant Shares, which
new Warrant shall in all other respects be identical with this Warrant.

     1.5 Payment of Taxes. The issuance of certificates for Warrant Shares shall
be made without charge to the Warrantholder for any documentary, stamp or
similar stock transfer or other issuance tax in respect thereto; provided that
the Warrantholder shall be required to pay any and all taxes which may be
payable in respect of any transfer involved in the issuance and delivery of any
certificate in a name other than that of the then Warrantholder as reflected
upon the books of the Company.

     1.6 Divisibility of Warrant; Transfer of Warrant. (a) Subject to the
provisions of this Section, this Warrant may be divided into warrants of one
thousand shares or multiples thereof, upon surrender at the office of the
Company located at 1221 Avenue of the Americas, 36th Floor, New York, New York
10020, without charge to any Warrantholder. Subject to the provisions of this
Section, upon such division, the Warrants may be transferred of record as the






                                                                               3


then Warrantholder may specify without charge to such Warrantholder (other than
any applicable transfer taxes).

     (b) Subject to the provisions of this Section 1, upon surrender of this
Warrant to the Company with a duly executed Assignment Form and funds sufficient
to pay any transfer tax, the Company shall, without charge, execute and deliver
a new Warrant or Warrants of like tenor in the name of the assignee named in
such Assignment Form, and this Warrant shall promptly be canceled. The term
"Warrant" as used in this Agreement shall be deemed to include any Warrants
issued in substitution or exchange for this Warrant.

     Section 2. Restrictions on Transfer; Restrictive Legends. Except as
otherwise permitted by this Section 2, each Warrant shall (and each Warrant
issued upon direct or indirect transfer or in substitution for any Warrant
pursuant to Section 1 or Section 4 shall) be stamped or otherwise imprinted with
a legend in substantially the following form:

          THIS WARRANT AND ANY SECURITIES ACQUIRED UPON THE EXERCISE OF THIS
     WARRANT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
     AMENDED, OR ANY STATE SECURITIES LAWS AND NEITHER THIS WARRANT NOR SUCH
     SECURITIES NOR ANY INTEREST THEREIN MAY BE OFFERED, SOLD, TRANSFERRED,
     PLEDGED OR OTHERWISE DISPOSED OF EXCEPT PURSUANT TO AN EFFECTIVE
     REGISTRATION STATEMENT UNDER SUCH ACT OR SUCH LAWS OR AN EXEMPTION FROM
     REGISTRATION UNDER SUCH ACT AND SUCH LAWS.

Except as otherwise permitted by this Section 2, each stock certificate for
Warrant Shares issued upon the exercise of any Warrant and each stock
certificate issued upon the direct or indirect transfer of any such Warrant
Shares shall be stamped or otherwise imprinted with a legend in substantially
the following form:

          THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
     REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE
     SECURITIES LAWS AND NEITHER THE SECURITIES NOR ANY INTEREST THEREIN MAY BE
     OFFERED, SOLD, TRANSFERRED, PLEDGED OR OTHERWISE DISPOSED OF EXCEPT
     PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT OR SUCH LAWS
     OR AN EXEMPTION FROM REGISTRATION UNDER SUCH ACT AND SUCH LAWS.

     Notwithstanding the foregoing, the Warrantholder may require the Company,
without expense to the Warrantholder, to issue a Warrant or a stock certificate
for Warrant Shares, in each case without a legend, if either (i) such Warrant or
such Warrant Shares, as the case may be, have been registered for resale under
the Securities Act or (ii) the Warrantholder has delivered to the Company an
opinion of legal counsel, which opinion shall be addressed to the Company and be
reasonably satisfactory in form and substance to the Company, to the effect that
such registration is not required with respect to such Warrant or such Warrant
Shares, as the case may be.






                                                                               4


     By acceptance of this Warrant, the Warrantholder expressly agrees that it
will at all times comply with the restrictions contained in Rule 144(e) under
the Securities Act (as in effect on the date hereof) when selling, transferring
or otherwise disposing of the Warrants, if applicable.

     Section 3. Reservation and Registration of Shares, Etc. The Company
covenants and agrees as follows:

          (a) all Warrant Shares which are issued upon the exercise of this
     Warrant will, upon issuance, be validly issued, fully paid, and
     nonassessable, not subject to any preemptive rights, and free from all
     taxes, liens, security interests, charges, and other encumbrances with
     respect to the issue thereof, other than taxes with respect to any transfer
     occurring contemporaneously with such issue;

          (b) during the period within which this Warrant may be exercised, the
     Company will at all times have authorized and reserved, and keep available
     free from preemptive rights and any taxes, liens, security interests,
     pledges, charges and other encumbrances, a sufficient number of shares of
     Common Stock to provide for the exercise of the rights represented by this
     Warrant; and

          (c) the Company will, from time to time, take all such actions as may
     be required to assure that the par value per share of the Warrant Shares is
     at all times equal to or less than the then effective Exercise Price.

     Section 4. Loss or Destruction of Warrant. Subject to the terms and
conditions hereof, upon receipt by the Company of evidence reasonably
satisfactory to it of the loss, theft, destruction or mutilation of this Warrant
and, in the case of loss, theft or destruction, of such bond or indemnification
as the Company may reasonably require, and, in the case of such mutilation, upon
surrender and cancellation of this Warrant, the Company will execute and deliver
a new Warrant of like tenor.

     Section 5. Ownership of Warrant. The Company may deem and treat the Person
in whose name this Warrant is registered as the holder and owner hereof
(notwithstanding any notations of ownership or writing hereon made by anyone
other than the Company) for all purposes and shall not be affected by any notice
to the contrary, until presentation of this Warrant for registration of
transfer.

     Section 6. Antidilution Provisions.

     6.1 Changes in Common Stock. In the event that at any time and from time to
time the Company shall (i) pay a dividend or make a distribution on Common Stock
in shares of Common Stock or other shares of Capital Stock, (ii) subdivide its
outstanding shares of Common Stock into a larger number of shares of Common
Stock, (iii) combine its outstanding shares of Common Stock into a smaller
number of shares of Common Stock or (iv) increase or decrease the number of
shares of Common Stock outstanding by reclassification, recapitalization or
reorganization of its Common Stock, then, in each such case, the number of
shares of Common Stock issuable upon exercise of this Warrant immediately after
the happening of such event shall be adjusted so that, after giving effect to
such adjustment, the Warrantholder shall be entitled to receive the number of
shares of Common Stock that the Warrantholder would have owned or






                                                                               5


have been entitled to receive had this Warrant been exercised immediately prior
to the happening of the events described above (or, in the case of a dividend or
distribution of Common Stock, immediately prior to the record date therefor),
and the Exercise Price shall be adjusted to the price (calculated to the nearest
100th of one cent) determined by multiplying the Exercise Price immediately
prior to such event by a fraction, the numerator of which shall be the number of
Warrant Shares purchasable upon the exercise of the Warrant immediately prior to
such event and the denominator of which shall be the number of Warrant Shares
purchasable after the adjustment referred to above. An adjustment made pursuant
to this Section 6.1 shall become effective immediately after the distribution
date, retroactive to the record date therefor in the case of a dividend or
distribution in shares of Common Stock or other shares of Capital Stock, and
shall become effective immediately after the effective date in the case of a
subdivision, combination or reclassification.

     6.2 Cash Dividends and Other Distributions. In the event that at any time
and from time to time the Company shall distribute to all holders of Common
Stock (i) any dividend or other distribution (including any dividend or
distribution made in connection with a consolidation or merger in which the
Company is the continuing corporation) of cash, evidences of its indebtedness,
shares of its Capital Stock or any other properties or securities or (ii) any
options, warrants or other rights to subscribe for or purchase any of the
foregoing (other than, in the case of clause (i) and (ii) above, (A) any
dividend or distribution described in Section 6.1 and (B) any rights, options,
warrants or securities described in Section 6.3 or Section 6.4), then the number
of shares of Common Stock issuable upon the exercise of this Warrant immediately
prior to such record date for any such dividend or distribution shall be
increased to a number determined by multiplying the number of shares of Common
Stock issuable upon the exercise of this Warrant immediately prior to such
record date for any such dividend or distribution by a fraction, the numerator
of which shall be the Current Market Value per share of Common Stock on the
record date for such dividend or distribution, and the denominator of which
shall be such Current Market Value per share of Common Stock less the sum of (x)
the amount of cash, if any, distributed per share of Common Stock and (y) the
then fair value (as determined in good faith by the Board of Directors, whose
determination shall be evidenced by a board resolution, a copy of which will be
sent to the Warrantholder upon request) of the portion, if any, of the
distribution applicable to one share of Common Stock consisting of evidences of
indebtedness, shares of stock, securities, other property, warrants, options or
subscription or purchase rights; and the Exercise Price shall be adjusted to a
number determined by dividing the Exercise Price immediately prior to such
record date by the above fraction. Such adjustments shall be made, and shall
only become effective, whenever any dividend or distribution is made; provided
that the Company is not required to make an adjustment pursuant to this Section
6.2 if at the time of such distribution the Company makes the same distribution
to the Warrantholder as it makes to holders of Common Stock pro rata based on
the number of shares of Common Stock for which this Warrant is exercisable. No
adjustment shall be made pursuant to this Section 6.2 which shall have the
effect of decreasing the number of shares of Common Stock issuable upon exercise
of this Warrant or increasing the Exercise Price.

     6.3 Issuance of Common Stock or Rights or Options. In the event that at any
time or from time to time the Company shall issue shares of Common Stock or
rights, options or warrants or securities convertible into or exchangeable for
Common Stock, other than in a bona fide underwritten public offering by or
through a syndicate managed by an investment bank of






                                                                               6


national or regional standing, for a consideration per share (which, in the case
of convertible, exchangeable or exercisable securities shall be the amount
received by the Company in consideration for the sale and issuance of such
convertible, exchangeable or exercisable securities plus the minimum aggregate
amount of additional consideration payable to the Company upon conversion,
exchange or exercise thereof (as determined in good faith by the Board of
Directors, whose determination shall be evidenced by a board resolution, a copy
of which will be sent to the Warrantholder upon request), provided that the
value attributable to such convertible, exchangeable or exercisable securities
when issued as part of a unit with debt or other obligations of the Company
shall be excluded to the extent it is a result of calculating the discount
applicable to such debt or other obligations of the Company under generally
accepted accounting principles) that is less than the greater of (a) the Current
Market Value per share of Common Stock as of the date the Company agrees in
writing to issue such shares and (b) the Exercise Price, then the number of
shares of Common Stock issuable upon the exercise of this Warrant immediately
after such date shall be determined by multiplying the number of shares of
Common Stock issuable upon exercise of this Warrant immediately prior to such
date by a fraction, the numerator of which shall be the number of shares of
Common Stock outstanding immediately preceding the date the Company agrees in
writing to issue such shares or rights, options, warrants or securities plus the
number of additional shares of Common Stock to be issued in such transaction or
offered for subscription or purchase or into which such securities are
convertible or exchangeable, and the denominator of which shall be the number of
shares of Common Stock outstanding immediately preceding the date the Company
agrees in writing to issue such shares or rights, options, warrants or
securities plus the total number of shares of Common Stock which the aggregate
consideration expected to be received by the Company upon the issuance of such
shares or the exercise, conversion or exchange of such rights, options, warrants
or securities (as determined in good faith by the Board of Directors, whose
determination shall be evidenced by a board resolution, a copy of which will be
sent to the Warrantholder upon request) would purchase at the greater of (a) the
Current Market Value per share of Common Stock as of the date the Company agrees
in writing to issue such shares or rights, options, warrants or securities and
(b) the Exercise Price, and in the event of any such adjustment, the Exercise
Price shall be adjusted to a number determined by dividing the Exercise Price
immediately prior to such date by the aforementioned fraction; provided that no
adjustment to the number of Warrant Shares issuable upon the exercise of this
Warrant or to the Exercise Price shall be made as a result of (i) the vesting or
exercise of this Warrant, (ii) the exercise, conversion or exchange of any
right, option, warrant or security, the issuance of which has previously
required an adjustment to the number of Warrant Shares issuable upon the
exercise of this Warrant or to the Exercise Price pursuant to this Section 6.3,
(iii) the exercise, conversion or exchange of any right, option, warrant or
security outstanding on the Issue Date (to the extent such exercise, conversion
or exchange is made in accordance with the terms of such right, option, warrant
or security as in effect on the Issue Date) or (iv) the issuance, exercise,
conversion or exchange of options to acquire Common Stock by officers, directors
or employees of the Company; and, provided further, that to the extent that the
aggregate proceeds from any issuance of shares of Common Stock subject to this
Section 6.3 from the date of issuance of this Warrant do not exceed $100
million, this Section 6.3 shall be applied without reference to the Exercise
Price in the determination of whether any adjustment shall be made to the number
of shares issuable upon exercise of this Warrant and in the application of the
formula for determining the extent of any such adjustment. Any adjustment
required by this Section 6.3






                                                                               7


shall be made, and shall only become effective, whenever such shares or such
rights, options, warrants or securities are issued. The terms of this provision
shall be reapplied if the terms of a right, option, warrant or security
convertible for or exchangeable into Common Stock are subsequently amended. No
adjustment shall be made pursuant to this Section 6.3 which shall have the
effect of decreasing the number of shares of Common Stock issuable upon exercise
of this Warrant or increasing the Exercise Price.

     6.4 Fundamental Transaction; Liquidation. (a) Except as provided in Section
6.4(b), in the event of a Fundamental Transaction, this Warrant will not
terminate and until the Expiration Date the Warrantholder shall have the right
to receive upon exercise of this Warrant the kind and amount of shares of
Capital Stock or other securities or property which the Warrantholder would have
been entitled to receive upon completion of, or as a result of, such Fundamental
Transaction had this Warrant been exercised immediately prior to such event or
to the relevant record date for any such entitlement, subject to adjustments
that shall be as nearly equivalent as may be practicable to the adjustments
provided for in this Section 6. Unless paragraph (b) is applicable to a
Fundamental Transaction, the Company shall cause that the surviving or acquiring
Person (the "Successor Company") in such Fundamental Transaction shall assume,
by written instrument reasonably satisfactory to the Warrantholder, the
obligation to deliver to the Warrantholder the shares of stock, securities or
assets to which, in accordance with the foregoing provisions, the Warrantholder
may be entitled and all other obligations of the Company under this Warrant. The
provisions of this Section 6.4(a) shall similarly apply to successive
Fundamental Transactions involving any Successor Company.

     (b) In the event of (i) a Fundamental Transaction with another Person
(other than a subsidiary of the Company) where consideration to the holders of
Common Stock in exchange for their shares is payable solely in cash or (ii) the
dissolution, liquidation or winding-up of the Company, the Warrantholder shall
be entitled to receive, upon surrender of this Warrant, such cash distributions
on an equal basis with the holders of Common Stock or other securities issuable
upon exercise of this Warrant, as if this Warrant had been exercised immediately
prior to such event, less the Exercise Price.

     In the event of any Fundamental Transaction described in this Section
6.4(b), the Successor Company and, in the event of any dissolution, liquidation
or winding-up of the Company, the Company, upon surrender of this Warrant, shall
promptly pay the Warrantholder the amounts to which it is entitled as described
above by delivering a check in such amount as is appropriate (or, in the case of
consideration other than cash, such other consideration as is appropriate) to
such Person or Persons as it may be directed in writing by the Warrantholder.

     6.5 Minimum Adjustment. The adjustments required by the preceding sections
of this Section 6 shall be made whenever and as often as any specified event
requiring an adjustment shall occur, except that no adjustment of the Exercise
Price or the number of shares of Common Stock issuable upon exercise of this
Warrant that would otherwise be required shall be made unless and until such
adjustment either by itself or with other adjustments not previously made
increases or decreases by at least 1% the Exercise Price or the number of shares
of Common Stock issuable upon exercise of this Warrant immediately prior to the
making of such adjustment. Any adjustment representing a change of less than
such minimum amount shall be carried forward and made as soon as such
adjustment, together with other adjustments required






                                                                               8


by this Section 6 and not previously made, would result in a minimum adjustment.
For the purpose of any adjustment, any specified event shall be deemed to have
occurred at the close of business on the date of its occurrence. In computing
adjustments under this Section 6, fractional interests in Common Stock shall be
taken into account to the nearest one-hundredth of a share.

     6.6 Notice of Adjustment. Whenever the Exercise Price or the number of
shares of Common Stock and other property, if any, issuable upon exercise of
this Warrant is adjusted, as herein provided, the Company shall deliver to the
Warrantholder an agreed upon procedures letter of a firm of independent
accountants selected by the Board of Directors (who may be the regular
accountants employed by the Company) setting forth, in reasonable detail, the
event requiring the adjustment and the method by which such adjustment was
calculated (including a description of the basis on which (i) the then fair
value of any evidences of indebtedness, other securities or property or
warrants, options or other subscription or purchase rights was determined and
(ii) the Current Market Value of the Common Stock was determined, if either of
such determinations were required), and specifying the Exercise Price and the
number of shares of Common Stock issuable upon exercise of this Warrant after
giving effect to such adjustment.

     6.7 Notice of Certain Transactions. In the event that the Company shall
propose to (a) pay any dividend payable in securities of any class to the
holders of its Common Stock or to make any other non-cash dividend or
distribution to the holders of its Common Stock, (b) offer the holders of its
Common Stock rights to subscribe for or to purchase any securities convertible
into shares of Common Stock or shares of stock of any class or any other
securities, rights or options, (c) issue any (i) shares of Common Stock, (ii)
rights, options or warrants entitling the holders thereof to subscribe for
shares of Common Stock or (iii) securities convertible into or exchangeable or
exercisable for Common Stock (in the case of (i), (ii) and (iii), if such event
would result in an adjustment hereunder), (d) effect any capital reorganization,
reclassification, consolidation or merger, (e) effect the voluntary or
involuntary dissolution, liquidation or winding-up of the Company, (f) make a
tender offer or exchange offer with respect to the Common Stock or (g) take any
action which would require an adjustment to the number of Warrant Shares
issuable upon the exercise of this Warrant or the Exercise Price, the Company
shall, within five days after deciding to take any such action or make any such
offer, send to the Warrantholder a notice of such proposed action or offer. Such
notice shall specify the record date for the purposes of such dividend,
distribution or rights, or the date such issuance or event is to take place and
the date of participation therein by the holders of Common Stock, if any such
date is to be fixed, and shall briefly indicate the effect, if any, of such
action on the Common Stock and on the number and kind of any other shares of
stock and on other property, if any, and the number of shares of Common Stock
and other property, if any, issuable upon exercise of this Warrant and the
Exercise Price after giving effect to any adjustment pursuant to Section 6 which
will be required as a result of such action. Such notice shall be given as
promptly as possible and (x) in the case of any action covered by clause (a) or
(b) above, at least 10 days prior to the record date for determining holders of
the Common Stock for purposes of such action or (y) in the case of any other
such action, at least 20 days prior to the date of the taking of such proposed
action or the date of participation therein by the holders of Common Stock,
whichever shall be the earlier.

     6.8 Adjustment to Warrant. The form of this Warrant need not be changed
because of any adjustment made pursuant to this Section 6.






                                                                               9


     Section 7. Reports Under Securities Exchange Act of 1934. With a view to
making available to the Holders the benefits of Rule 144 promulgated under the
Securities Act or any other similar rule or regulation of the SEC that may at
any time permit the Warrantholders to sell securities of the Company to the
public without registration ("Rule 144"), the Company agrees to:

          (a) make and keep public information available, as those terms are
     understood and defined in Rule 144, at all times;

          (b) file with the SEC in a timely manner all reports and other
     documents required of the Company under the Securities Act and the Exchange
     Act; and

          (c) furnish to each Holder so long as such Holder owns Warrants,
     promptly upon request, (i) a written statement by the Company that it has
     complied with the reporting requirements of Rule 144, the Securities Act
     and the Exchange Act, (ii) a copy of the most recent annual or quarterly
     report of the Company and such other reports and documents so filed by the
     Company, and (iii) such other information as may be reasonably requested to
     permit the Holders to sell such securities without registration.

     Section 8. Required Registration. The Company shall use its best efforts to
cause a shelf registration statement relating to the resale of the Warrant
Shares to be filed with the SEC as promptly as possible, but in no event later
than April 4, 2003, following the issuance of this Warrant.

     Section 9. Amendments. Any provision of this Warrant may be amended and the
observance thereof may be waived (either generally or in a particular instance
and either retroactively or prospectively), only with the written consent or
approval of the Company and the Holders representing two-thirds of then issuable
Warrant Shares; provided that it is not necessary that the exact form of the
amendment be approved by the Holders representing two-thirds of then issuable
Warrant Shares if such Holders have approved the substance of such amendment.
Any amendment or waiver effected in accordance with this Section 9 shall be
binding upon each Holder and the Company. Notwithstanding anything to the
contrary herein, the consent of each Holder affected shall be required for any
amendment pursuant to which the number of Warrant Shares purchasable upon
exercise of the Warrants would be decreased (other than in accordance with
Section 6 hereof).

     Section 10. Expiration of the Warrant. The obligations of the Company
pursuant to this Warrant shall terminate on the Expiration Date.

     Section 11. Definitions. As used herein, unless the context otherwise
requires, the following terms have the following respective meanings:

          "Affiliate" shall mean, with respect to any specified Person, (1) any
     other Person directly or indirectly controlling or controlled by or under
     direct or indirect common control with such specified Person or (2) any
     other Person that owns, directly or indirectly, 25% or more of such
     specified Person's Voting Stock or any executive officer or director of any
     such specified Person or other Person or, with respect to any natural
     Person, any Person having a relationship with such Person by blood,
     marriage or






                                                                              10


     adoption not more remote than first cousin. For the purposes of this
     definition, "control", when used with respect to any specified 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; and the terms "controlling" and "controlled" have
     meanings correlative to the foregoing.

          "Assignment Form" shall mean an instrument of transfer of a warrant in
     the form annexed hereto as Exhibit B.

          "Board of Directors" shall mean the Board of Directors of the Company
     or any duly authorized committee thereof.

          "Business Day" shall mean any day other than a Saturday, Sunday or a
     day on which banks are required or authorized by law to close in The City
     of New York, State of New York.

          "By-laws" shall mean the Amended and Restated By-laws of the Company,
     as the same may be amended and in effect from time to time.

          "Capital Stock" of any Person shall mean any and all shares,
     interests, rights to purchase, warrants, options, participations or other
     equivalents of or interests in (however designated) equity of such Person,
     including any preferred stock, but excluding any debt securities
     convertible into such equity.

          "Certificate of Incorporation" shall mean the Amended and Restated
     Certificate of Incorporation of the Company, as the same may be amended and
     in effect from time to time.

          "Common Stock" shall have the meaning specified on the first page of
     this Warrant.

          "Company" shall have the meaning specified on the first page of this
     Warrant.

          "Contractual Obligation" shall mean as to any Person, any agreement,
     undertaking, contract, indenture, mortgage, deed of trust or other
     instrument to which such Person is a party or by which it or any of its
     property is bound.

          "Current Market Value" per share of Common Stock of the Company or any
     other security at any date shall mean (1) if the security is not registered
     under the Exchange Act, (a) the value of the security, determined in good
     faith by the Board of Directors and certified in a board resolution, based
     on the most recently completed arms-length transaction between the Company
     and a Person other than an Affiliate of the Company and the closing of
     which occurs on such date or shall have occurred within the six-month
     period preceding such date, or (b) if no such transaction shall have
     occurred on such date or within such six-month period, the fair market
     value of the security as determined by a nationally or regionally
     recognized independent financial expert (provided that, in the case of the
     calculation of Current Market Value for determining the cash value of
     fractional shares, any such determination within six months that is, in the
     good faith






                                                                              11


     judgment of the Board of Directors, a reasonable determination of value,
     may be utilized) or (2) if the security is registered under the Exchange
     Act, (a) the average of the daily closing sales prices of the securities
     for the 20 consecutive trading days immediately preceding such date, or (b)
     if the securities have been registered under the Exchange Act for less than
     20 consecutive trading days before such date, then the average of the daily
     closing sales prices for all of the trading days before such date for which
     closing sales prices are available, in the case of each of (2)(a) and
     (2)(b), as certified to the Warrantholder by the President, any Vice
     President or the Chief Financial Officer of the Company. The closing sales
     price for each such trading day shall be: (A) in the case of a security
     listed or admitted to trading on any United States national securities
     exchange or quotation system, the closing sales price, regular way, on such
     day, or if no sale takes place on such day, the average of the closing bid
     and asked prices on such day; (B) in the case of a security not then listed
     or admitted to trading on any national securities exchange or quotation
     system, the last reported sale price on such day, or if no sale takes place
     on such day, the average of the closing bid and asked prices on such day,
     as reported by a reputable quotation source designated by the Company; (C)
     in the case of a security not then listed or admitted to trading on any
     national securities exchange or quotation system and as to which no such
     reported sale price or bid and asked prices are available, the average of
     the reported high bid and low asked prices on such day, as reported by a
     reputable quotation service, or a newspaper of general circulation in the
     Borough of Manhattan, City and State of New York, customarily published on
     each Business Day, designated by the Company, or if there shall be no bid
     and asked prices on such day, the average of the high bid and low asked
     prices, as so reported, on the most recent day (not more than 30 days prior
     to the date in question) for which prices have been so reported; and (D) if
     there are not bid and asked prices reported during the 30 days prior to the
     date in question, the Current Market Value shall be determined as if the
     securities were not registered under the Exchange Act.

          "Exchange Act" shall mean the Securities Exchange Act of 1934 or any
     similar Federal statute, and the rules and regulations of the SEC
     thereunder, all as the same shall be in effect at the time. Reference to a
     particular section of the Exchange Act shall include a reference to a
     comparable section, if any, of any such similar Federal statute.

          "Exercise Form" shall mean a request to exercise this Warrant in the
     form annexed hereto as Exhibit A.

          "Exercise Price" shall have the meaning specified on the first page of
     this Warrant.

          "Expiration Date" shall have the meaning specified on the first page
     of this Warrant.

          "FCC" shall mean the Federal Communications Commission, or any
     successor to such agency.

          "Fundamental Transaction" shall mean any transaction or series of
     related transactions by which the Company consolidates with or merges with
     or into any other






                                                                              12


     Person or sells, assigns, transfers, leases, conveys or otherwise disposes
     of all or substantially all of its properties and assets to another Person
     or group of affiliated Persons or is a party to a merger or binding share
     exchange which reclassifies or changes its outstanding Common Stock;
     provided that the Company may effect any of such transactions with a
     wholly-owned subsidiary where after such transaction the Company or, in the
     event the Company is not the surviving entity, the surviving entity has a
     consolidated net worth which is no less than the consolidated net worth of
     the Company prior to such transaction.

          "Governmental Authority" shall mean the government of any nation,
     state, city, locality or other political subdivision of any thereof, and
     any entity exercising executive, legislative, judicial, regulatory or
     administrative functions of or pertaining to government or any
     international regulatory body having or asserting jurisdiction over a
     Person, its business or its properties.

          "Holder(s)" shall mean the holder(s) of the Series A Warrants and
     holders of the Series B Warrants.

          "HSR Act" shall mean the Hart-Scott-Rodino Antitrust Improvements Act
     of 1976, as amended, and the rules and regulations of the Federal Trade
     Commission thereunder.

          "Issue Date" shall mean the date on which this Warrant is originally
     issued.

          "Lien" shall mean any mortgage, deed of trust, pledge, hypothecation,
     assignment, encumbrance, lien (statutory or other), restriction or other
     security interest of any kind or nature whatsoever.

          "Nasdaq" shall mean the National Association of Securities Dealers
     Automated Quotations System.

          "Person" shall mean any individual, firm, corporation, partnership,
     limited liability company, trust, incorporated or unincorporated
     association, joint venture, joint stock company, Governmental Authority or
     other entity of any kind.

          "Requirement of Law" shall mean, as to any Person, the Certificate of
     Incorporation and By-laws, or other organizational or governing documents,
     of such Person, and any law, treaty, rule, regulation, qualification,
     license or franchise or determination of an arbitrator or a court or other
     Governmental Authority, in each case applicable or binding upon such Person
     or any of its property or to which such Person or any of its property is
     subject or pertaining to any or all of the transactions contemplated
     hereby.

          "Rule 144" shall have the meaning specified in Section 7.

          "SEC" shall mean the Securities and Exchange Commission or any other
     Federal agency at the time administering the Securities Act or the Exchange
     Act, whichever is the relevant statute for the particular purpose.






                                                                              13


          "Securities Act" shall have the meaning specified on the first page of
     this Warrant, or any similar Federal statute, and the rules and regulations
     of the SEC thereunder, all as the same shall be in effect at the time.
     Reference to a particular section of the Securities Act, shall include a
     reference to the comparable section, if any, of any such similar Federal
     statute.

          "Series A Warrants" shall mean the Series A Warrants issued on
     ___________ by the Company to _______________________.

          "Series B Warrants" shall mean the Series B Warrants issued on
     ___________ by the Company to _______________________.

          "Subsidiary" shall mean, in respect of any Person, any other Person of
     which, at the time as of which any determination is made, such Person or
     one or more of its subsidiaries has, directly or indirectly, voting
     control.

          "Successor Company" shall have the meaning specified in Section 6.4 of
     this Warrant.

          "Voting Stock" shall mean, with respect to any Person, any class or
     classes of Capital Stock pursuant to which the holders thereof have the
     general voting power under ordinary circumstances to elect at least a
     majority of the board of directors, managers or trustees of such Person
     (irrespective of whether or not, at the time, stock of any other class or
     classes shall have, or might have, voting power by reason of the happening
     of any contingency).

          "Warrantholder" shall have the meaning specified on the first page of
     this Warrant.

          "Warrant Shares" shall have the meaning specified on the first page of
     this Warrant.






                                                                              14


     Section 12. No Impairment. The Company shall not by any action, including,
without limitation, amending the Certificate of Incorporation or through any
reorganization, transfer of assets, consolidation, merger, dissolution, issue or
sale of securities or any other voluntary action, avoid or seek to avoid the
observance or performance of any of the terms of this Warrant, but shall at all
times in good faith assist in the carrying out of all such terms and in the
taking of all such reasonable actions as may be necessary or appropriate to
protect the rights of the Warrantholder against impairment. Without limiting the
generality of the foregoing, the Company shall (a) take all such actions as may
be necessary or appropriate in order that the Company may validly and legally
issue fully paid and nonassessable shares of Common Stock upon the exercise of
this Warrant, and (b) provide reasonable assistance to the Warrantholder in
obtaining all authorizations, exemptions or consents from any Governmental
Authority which may be necessary in connection with the exercise of this
Warrant.

     Section 13. Miscellaneous.

     13.1 Entire Agreement. This Warrant constitutes the entire agreement
between the Company and the Warrantholder with respect to the Warrants.

     13.2 Binding Effects; Benefits. This Warrant shall inure to the benefit of
and shall be binding upon the Company and the Warrantholder and their respective
heirs, legal representatives, successors and assigns. Nothing in this Warrant,
expressed or implied, is intended to or shall confer on any Person other than
the Company and the Warrantholder, or their respective heirs, legal
representatives, successors or assigns, any rights, remedies, obligations or
liabilities under or by reason of this Warrant.

     13.3 Section and Other Headings. The section and other headings contained
in this Warrant are for reference purposes only and shall not be deemed to be a
part of this Warrant or to affect the meaning or interpretation of this Warrant.

     13.4 Pronouns. All pronouns and any variations thereof refer to the
masculine, feminine or neuter, singular or plural, as the context may require.

     13.5 Further Assurances. Each of the Company and the Warrantholder shall do
and perform all such further acts and things and execute and deliver all such
other certificates, instruments and documents as the Company or the
Warrantholder may, at any time and from time to time, reasonably request in
connection with the performance of any of the provisions of this Warrant.

     13.6 Notices. All notices and other communications required or permitted to
be given under this Warrant shall be in writing and shall be deemed to have been
duly given if (i) delivered personally or (ii) sent by facsimile or recognized
overnight courier or by United States first class certified mail, postage
prepaid, to the parties hereto at the following addresses or to such other
address as any party hereto shall hereafter specify by notice to the other party
hereto:

     if to the Company, addressed to:

     Sirius Satellite Radio Inc.
     1221 Avenue of the Americas






                                                                              15


     36th Floor
     New York, New York  10020
     Attention: Chief Financial Officer
     Telecopy:  212 584-5353

     if to the Warrantholder, addressed to:

Except as otherwise provided herein, all such notices and communications shall
be deemed to have been received (a) on the date of delivery thereof, if
delivered personally or sent by facsimile, (b) on the second Business Day
following delivery into the custody of an overnight courier service, if sent by
overnight courier, provided that such delivery is made before such courier's
deadline for next-day delivery, or (c) on the third Business Day after the
mailing thereof.

     13.7 Separability. Any term or provision of this Warrant which is invalid
or unenforceable in any jurisdiction shall, as to such jurisdiction, be
ineffective to the extent of such invalidity or unenforceability without
rendering invalid or unenforceable the terms and provisions of this Warrant or
affecting the validity or enforceability of any of the terms or provisions of
this Warrant in any other jurisdiction.

     13.8 Governing Law. This Warrant shall be deemed to be a contract made
under the laws of New York and for all purposes shall be governed by and
construed in accordance with the laws of such State applicable to such
agreements made and to be performed entirely within such State.

     13.9 No Rights or Liabilities as Stockholder. Nothing contained in this
Warrant shall be deemed to confer upon the Warrantholder any rights as a
stockholder of the Company or as imposing any liabilities on the Warrantholder
to purchase any securities whether such liabilities are asserted by the Company
or by creditors or stockholders of the Company or otherwise.

     13.10 Representations of the Company. The Company hereby represents and
warrants, as of the date hereof, to the Warrantholder as follows:

          (a) Corporate Existence and Power. The Company (i) is a corporation
     duly incorporated, validly existing and in good standing under the laws of
     the State of Delaware; (ii) has all requisite corporate power and authority
     to own and operate its property, to lease the property it operates as
     lessee and to conduct the business in which it is engaged; and (iii) has
     the corporate power and authority to execute, deliver and perform its
     obligations under this Warrant. The Company is duly qualified to do
     business as a foreign corporation in, and is in good standing under the
     laws of, each jurisdiction in






                                                                              16


     which the conduct of its business or the nature of the property owned
     requires such qualification.

          (b) Corporate Authorization; No Contravention. The execution, delivery
     and performance by the Company of this Warrant and the transactions
     contemplated hereby, including, without limitation, the sale, issuance and
     delivery of the Warrant Shares, (i) have been duly authorized by all
     necessary corporate action of the Company; (ii) do not contravene the terms
     of the Certificate of Incorporation or By-laws; and (iii) do not violate,
     conflict with or result in any breach or contravention of, or the creation
     of any Lien under, any Contractual Obligation of the Company or any
     Requirement of Law applicable to the Company.

          (c) Issuance of Warrant Shares. The Warrant Shares have been duly
     authorized and reserved for issuance. When issued, such shares will be
     validly issued, fully paid and non-assessable, and free and clear of all
     Liens and preemptive rights, and the holders thereof shall be entitled to
     all rights and preferences accorded to a holder of Common Stock.

     13.11 Binding Effect. This Warrant has been duly executed and delivered by
the Company and constitutes the legal, valid and binding obligation of the
Company enforceable against the Company in accordance with its terms, except as
enforceability may be limited by applicable bankruptcy, insolvency, fraudulent
conveyance or transfer, moratorium or other similar laws affecting the
enforcement of creditors' rights generally and by general principles of equity.

     13.12 Specific Performance. The Company and the Warrantholder acknowledge
that the Warrant and the Warrant Shares are unique and that neither party hereto
will have an adequate remedy at law if the other breaches any covenant contained
herein or fails to perform any of its obligations under this Warrant.
Accordingly, each party agrees that the other shall have the right, in addition
to any other rights which it may have, to specific performance and equitable
injunctive relief if the other party shall fail or threaten to fail to perform
any of its obligations under this Warrant.

     13.13 Third Parties. Nothing expressed or implied in this Warrant is
intended or shall be construed to confer upon or give to any third party any
rights or remedies by virtue of this Warrant or any exercise or non-exercise of
the Warrant Shares granted hereby.






                                                                              17


     IN WITNESS WHEREOF, the Company has caused this Warrant to be signed by its
duly authorized officer.

                                        SIRIUS SATELLITE RADIO INC.


                                        By:
                                            ------------------------------------
                                            Patrick L. Donnelly
                                            Executive Vice President and
                                            General Counsel


Dated:

Attest:


By:
    ---------------------------------
            Douglas A. Kaplan
           Assistant Secretary






                                                                       Exhibit A

                                  EXERCISE FORM

                 (To be executed upon exercise of this Warrant)

     The undersigned hereby irrevocably elects to exercise the right,
represented by this Warrant, to purchase __________ shares of Common Stock and
herewith tenders payment for such Common Stock to the order of Sirius Satellite
Radio Inc. in the amount of $__________, which amount includes payment of the
par value for _________ shares of the Common Stock, in accordance with the terms
of this Warrant. The undersigned requests that a certificate for such shares of
Common Stock be registered in the name of __________________ and that such
certificates be delivered to __________________ whose address is
_________________________________.

Dated: _______________


                                               ---------------------------------
                                                       Signature

                                               ---------------------------------
                                                       (Print Name)

                                               ---------------------------------
                                                       (Street Address)

                                               ---------------------------------
                                               (City)  (State)     (Zip Code)

Signed in the Presence of:


- -------------------------------------






                                                                       Exhibit B

                               FORM OF ASSIGNMENT

               (To be executed only upon transfer of this Warrant)

     For value received, the undersigned registered holder of the within Warrant
hereby sells, assigns and transfers unto ______________________ the right
represented by such Warrant to purchase ________________ shares of Common Stock
of Sirius Satellite Radio Inc. to which such Warrant relates and all other
rights of the Warrantholder under the within Warrant, and appoints
______________________ Attorney to make such transfer on the books of Sirius
Satellite Radio Inc. maintained for such purpose, with full power of
substitution in the premises. This sale, assignment and transfer has been
previously approved in writing by Sirius Satellite Radio Inc.

Dated: _______________


                                         ---------------------------------------
                                                        Signature

                                         ---------------------------------------
                                                      (Print Name)

                                         ---------------------------------------
                                                    (Street Address)

                                         ---------------------------------------
                                         (City)          (State)      (Zip Code)


Signed in the Presence of:


- -------------------------------------