EXHIBIT 32.1

                           CERTIFICATION PURSUANT TO
                 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO
                 SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

    In connection with the Annual Report of Sirius Satellite Radio Inc. (the
'Company') on Form 10-K for the year ended December 31, 2003 as filed with the
Securities and Exchange Commission on the date hereof (the 'Report'), I, Joseph
P. Clayton, President and Chief Executive Officer of the Company, certify,
pursuant to 18 U.S.C. 'SS' 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that:

        1. The Report fully complies with the requirements of Section 13(a) or
    15(d) of the Securities Exchange Act of 1934; and

        2. The information contained in the Report fairly presents, in all
    material respects, the financial condition and results of operations of the
    Company.

Date: March 12, 2004

/s/ Joseph P. Clayton
- -------------------------------------
Joseph P. Clayton
President and Chief Executive Officer

    A signed original of this written statement required by Section 906, or
other document authenticating, acknowledging, or otherwise adopting the
signature that appears in typed form within the electronic version of this
written statement required by Section 906, has been provided to the Company and
will be retained by the Company and furnished to the Securities and Exchange
Commission or its staff upon request.