Exhibit 99.1


                           SIRIUS SATELLITE RADIO INC.

                            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 period ending December 31, 2002 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. Section 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 result of operations of the
Company.


                                      By: /s/ Joseph P. Clayton
                                         --------------------------------------
                                          Joseph P. Clayton
                                          President and Chief Executive Officer
                                          (Principal Executive Officer)


March 28, 2003