EXHIBIT 5.1


                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON
                           1285 Avenue of the Americas
                            New York, New York 10019



                                                July 2, 1999

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

                       Registration Statement on Form S-4
                                of CD Radio Inc.
                       ----------------------------------

Ladies and Gentlemen:

          In connection with the Registration Statement on Form S-4 (the
"Registration Statement") filed by CD Radio Inc., a Delaware corporation (the
"Company"), with the Securities and Exchange Commission (the "Commission") on
the date of this letter, 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 the Company's $200,000,000 aggregate principal
amount of 14 1/2% Senior Secured Notes











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due 2009 (the "Exchange Notes"). The Exchange Notes are to be offered in
exchange for the outstanding $200,000,000 aggregate principal amount of 14 1/2%
Senior Secured Notes due 2009 (the "Initial Notes") issued and sold by the
Company on May 18, 1999 as part of an offering exempt from registration under
the Act. The Exchange Notes will be issued by the Company under the Indenture
(the "Indenture"), dated as of May 15, 1999, between the Company and United
States Trust Company of New York, as trustee (the "Trustee"). Capitalized terms
used in this letter and not otherwise defined have the respective meanings given
those terms in the Registration Statement.

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

          (i) the Registration Statement;

          (ii) the Indenture included as Exhibit 4.4.2 to the Registration
Statement;

          (iii) the form of the Exchange Notes included as Exhibit 4.4.3 to the
Registration Statement; and

          (iv) The Notes Registration Rights Agreement included as Exhibit 4.4.1
to the Registration Statement.

          In addition, we have examined: (i) those corporate records of the
Company as we have considered appropriate, including copies of its Amended and











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Restated Certificate of Incorporation and Amended and Restated By-laws, as in
effect on the date of this letter (collectively, the "Charter Documents"), and
certified copies of resolutions of the executive committee of the board of
directors of the Company relating to the Exchange Notes; and (ii) 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, (i) that the Exchange Notes will be
issued substantially as described in the Registration Statement and in the form
reviewed by us and that any information omitted from the form will be properly
added, (ii) the genuineness of all signatures, (iii) the authenticity of all
documents submitted to us as originals, (iv) 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, (v) the
authenticity of the latter documents; (vi) that the statements regarding matters
of fact in the certificates, records, agreements, instruments and documents that
we examined are accurate and complete, and (vii) the legal capacity of all
individuals who have executed any of the documents which we examined.

          We have also assumed, without independent investigation, that (i) the
Indenture was duly authorized, executed and delivered by the Trustee, (ii) the
Indenture is a valid and binding obligation of the Trustee, (iii) the Exchange
Notes











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will be issued in accordance with the Indenture as described in the Registration
Statement and (iv) the Exchange Notes will be duly authenticated by the Trustee
in accordance with the Indenture.

          In expressing the opinion 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 foregoing, and subject to the stated assumptions,
exceptions and qualifications, we are of the opinion that:

          1. The Indenture represents a valid and binding obligation of the
Company enforceable against the Company in accordance with its terms, except as
enforceability 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).

          2. When issued, authenticated and delivered in accordance with the
terms of the Indenture, the Exchange Notes will be legal, valid and binding
obligations of the Company enforceable against the Company in accordance with
their terms, except as enforceability may be limited by (a) bankruptcy,
insolvency, fraudulent conveyance or transfer, reorganization, moratorium and
other similar laws







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affecting creditors' rights generally and (b) general principles of equity
(regardless of whether enforcement is considered in a proceeding in equity or at
law).

          Our opinions expressed above are limited to the laws of the State of
New York and the federal laws of the United States of America. 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,

                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON