PAUL, WEISS, RIFKIND, WHARTON & GARRISON
                           1285 Avenue of the Americas
                          New York, New York 10019-6064

                                                               November 19, 1997

CD Radio Inc.
1001 22nd Street N.W.
Washington DC 20037

                                CD Radio Inc. --

                       Registration Statement on Form S-3

                           Registration No. 333-34767

Ladies and Gentlemen:

               In connection with the above-captioned Registration Statement
(the "Registration Statement"), filed with the Securities and Exchange
Commission pursuant to the Securities Act of 1933, as amended (the "Act"), and
the rules and regulations promulgated thereunder (the "Rules"), we have been
requested by CD Radio Inc., a Delaware corporation (the "Company"), to furnish
our opinion as to the legality of the shares of the Common Stock, par value
$.001 per share (the "Common Stock"), registered thereunder.

               In connection with the furnishing of this opinion, we have
reviewed (i) the Registration Statement (including all amendments thereto filed
on or prior to the date hereof); (ii) the Company's Certificate of Incorporation
and the By-laws of the Company; and (iii) records of certain of the Company's
corporate proceedings. We also have examined and relied upon representations as
to factual matters contained in certificates of officers of the Company, and
have made such other investigations of fact and law and have examined and relied
upon the originals, or copies certified or














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otherwise identified to our satisfaction, of such documents, records,
certificates or other instruments, and upon such factual information otherwise
supplied to us, as in our judgment are necessary or appropriate to render the
opinion expressed below. In addition, we have assumed, without independent
investigation, the genuineness of all signatures, the authenticity of all
documents submitted to us as originals and the conformity of original documents
to all documents submitted to us as certified, photostatic, reproduced or
conformed copies, the authenticity of all such latter documents and the legal
capacity of all individuals who have executed any of the documents.

               Based upon the foregoing, we are of the opinion that when issued
and paid for pursuant to the Purchase Agreement and the U.S. Purchase Agreement
the Common Stock will be duly authorized, validly issued, fully paid and
nonassessable.

               Our opinion expressed above is limited to the General Corporation
Law of the State of Delaware. Please be advised that no member of this firm is
admitted to practice in the State of Delaware. Our opinion is rendered only with
respect to laws, and the rules, regulations and orders thereunder, which are
currently in effect.

               We hereby consent to the use of this opinion as an Exhibit to the
Registration Statement and to the use of our name under the heading "Legal
Opinions" contained in the Prospectus included in the Registration Statement. In
giving this consent, we do not thereby admit that we come within the category of
persons whose consent is required by the Act or the Rules.


                                          Very truly yours,

                             PAUL, WEISS, RIFKIND, WHARTON & GARRISON













CD Radio Inc.                                                                  3


Prepared by:
               --------------------------------
               Jonathan G. L. King

Signed by:
               --------------------------------
               Mitchell S. Fishman

Reviewed by:
               --------------------------------
               Seymour Hertz