EXHIBIT 5.1

                                  July 20, 2001

Sirius Satellite Radio Inc.
1221 Avenue of the Americas
New York, New York 10020

                       Registration Statement on Form S-3
                         of Sirius Satellite Radio Inc.

Ladies and Gentlemen:

          In connection with the Registration Statement on Form S-3 (the
"Registration Statement") filed by Sirius Satellite Radio Inc., a Delaware
corporation (the "Company"), with the Securities and Exchange Commission (the
"Commission") today, as provided by the Securities Act of 1933, as amended (the
"Act"), and the rules and regulations under the Act, we have been requested to
render our opinion as to the legality of the securities being registered under
the Registration Statement. The Registration Statement relates to the
registration under the Act of (1) the Company's warrants (the "Warrants") to
purchase shares of the Company's common stock, par value $0.001 per share (the
"Common Stock"), and (2) the shares (the "Warrant Shares") of the Company's
Common Stock issuable upon the conversion of the Warrants.







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          In connection with this opinion, we have examined originals, conformed
copies or photocopies, certified or otherwise identified to our satisfaction, of
the following documents:

          1. the Registration Statement; and

          2. the Amended and Restated Warrant Agreement (the "Warrant
     Agreement") between the Company and United States Trust Company of New
     York, as warrant agent (the "Warrant Agent") dated as of December 27, 2000.

          In addition, we have examined: (1) those corporate records of the
Company as we have considered appropriate, including copies of its Amended and
Restated Certificate of Incorporation and Amended and Restated By-laws, as in
effect on the date of this letter, and copies of resolutions of the board of
directors of the Company relating to the Warrant Agreement contained in draft
minutes of the February 6, 2001 meeting of the board of directors (which we have
assumed, for purposes of this opinion, will be finalized in their draft form);
and (2) those other certificates, agreements and documents as we deemed relevant
and necessary as a basis for the opinions expressed below.

          In our examination of the documents referred to above, we have
assumed, without independent investigation, (1) the genuineness of all
signatures, (2) the authenticity of all documents submitted to us as originals,
(3) the conformity to the original documents of all documents submitted to us as
certified, photostatic, reproduced or conformed copies of validly existing
agreements or other documents, (4) the authenticity of the latter documents, (5)
that the statements regarding matters of fact in the certificates, records,
agreements, instruments and documents that we examined are








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accurate and complete and (6) the legal capacity of all individuals who have
executed any of the documents which we examined.

          In expressing the opinions set forth below, we have relied upon the
factual matters contained in the representations and warranties of the Company
made in the documents and upon certificates of public officials and officers of
the Company.

          Based on the above, and subject to the stated assumptions, exceptions
and qualifications, we are of the opinion that:

          1. The Warrant Agreement has been duly authorized, executed and
delivered by the Company and (assuming its due authorization, execution and
delivery by the Warrant Agent) constitutes a valid and binding agreement of the
Company, enforceable against the Company in accordance with its terms.

          2. The Warrants were duly authorized and validly issued and are fully
paid and nonassessable.

          3. The Warrant Shares are duly authorized and, when issued, delivered
and paid for in accordance with the Warrant Agreement and as described in the
Registration Statement, the Warrant Shares will be validly issued, fully paid
and nonassessable.

          Our opinions are subject to the qualification that the enforceability
of the Warrant Agreement may be subject to (a) bankruptcy, insolvency,
fraudulent conveyance or transfer, reorganization, moratorium or other similar
laws affecting creditors' rights generally and (b) general principles of equity
(regardless of whether enforcement is considered in a proceeding in equity or at
law).






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          Our opinions are limited to the laws of the State of New York, the
federal laws of the United States of America and the General Corporation Law of
the State of Delaware. Our opinions are rendered only with respect to the laws,
and the rules, regulations and orders under those laws, that are currently in
effect. Please be advised that no member of this firm is admitted to practice in
the State of Delaware.

          We consent to the use of our name in the Registration Statement and in
the prospectus in the Registration Statement as it appears in the caption "Legal
Matters" and to the use of this opinion as an exhibit to the Registration
Statement. In giving this consent, we do not admit that we come within the
category of persons whose consent is required by the Act or by the rules and
regulations under the Act.

                                    Very truly yours,


                                    /s/ PAUL, WEISS, RIFKIND, WHARTON & GARRISON

                                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON