Document:

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                                                                    EXHIBIT 4.12

                            ECHOSTAR DBS CORPORATION

                          9 1/8% SENIOR NOTES DUE 2009

                          FIRST SUPPLEMENTAL INDENTURE

                          Dated as of December 31, 2003

                         U.S. Bank National Association

                                     Trustee

<PAGE>

                  FIRST SUPPLEMENTAL INDENTURE, dated as of December 31, 2003
(the "Supplemental Indenture"), among EchoStar DBS Corporation, a Colorado
corporation (the "Company"), EchoStar Satellite Operating Corporation, a
Colorado corporation (the "New Guarantor"), and U.S. Bank National Association,
as trustee (the "Trustee"), to the indenture, dated as of December 28, 2001 (the
"Original Indenture"), by and between the Company, the Guarantors (as defined in
the Original Indenture) and the Trustee, for the 9 1/8% Senior Notes due 2009
(the "Notes") of the Company.

                                    RECITALS

                  The Company, the Guarantors and the Trustee have heretofore
executed and delivered the Original Indenture providing for the issuance of the
Notes.

                  The Company or one of the Guarantors has determined to
transfer property or assets to the New Guarantor.

                  Pursuant to Section 4.13 of the Original Indenture, the
Company and the New Guarantor have duly authorized the execution and delivery of
this Supplemental Indenture to provide for the addition of the New Guarantor to
the list of Guarantors under the Original Indenture.

                  New Guarantor has executed and delivers herewith the guarantee
(the "New Guarantee") attached hereto as Exhibit A.

                  All things necessary (i) to make the New Guarantee when
executed by the New Guarantor and delivered hereunder the valid obligations of
the New Guarantor and (ii) to make this Supplemental Indenture a valid agreement
of the Company and the New Guarantor, all in accordance with their respective
terms, have been done.

                  In consideration of the premises and the covenants and
agreements contained herein, and for other good and valuable consideration the
receipt of which is hereby acknowledged, it is mutually agreed as follows for
the equal and ratable benefit of the Holders of the Notes.

SECTION 1.        Additional Subsidiary Guarantee.

                  Pursuant to Section 4.13 of the Original Indenture, New
Guarantor is hereby made a party to the Original Indenture as a "Guarantor", and
as a "Guarantor" the New Guarantor unconditionally guarantees all of the
Company's obligations under the Notes on the terms set forth in the Original
Indenture.

SECTION 2.        Effect on the Original Indenture.

                  Except as amended by this Supplement Indenture, the Original
Indenture shall remain in full force and effect and is hereby ratified and
confirmed.

SECTION 3.        Governing Law.

                  The internal law of the State of New York shall govern and be
used to construe this Supplemental Indenture and the New Guarantee.

                                       1

<PAGE>

SECTION 4.        Defined Terms.

                  Unless otherwise indicated, capitalized terms used in this
Supplemental Indenture and not defined shall have the respective meanings
assigned to them in the Original Indenture.

SECTION 5.        Counterpart Originals.

                  The parties may sign any number of copies of this Supplemental
Indenture. Each signed copy shall be an original, but all of them together
represent the same agreement.

SECTION 6.        Effect of Headings.

                  Section headings herein are for convenience only and shall not
affect the construction hereof.

SECTION 7.        Severability.

                  In case any provision in this Supplemental Indenture shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions shall not in any way be effected or impaired thereby.

                                       2

<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have caused this
Supplemental Indenture to be duly executed as of the day and year first above
written.

                            ECHOSTAR DBS CORPORATION,
                               a Colorado corporation

                            By:    /s/ David K. Moskowitz
                                ------------------------------------------------
                                Name:  David K. Moskowitz
                                Title: Senior Vice President

                            U.S. BANK NATIONAL ASSOCIATION,
                                 as Trustee

                            By:    /s/ Richard H. Prokosch
                                ------------------------------------------------
                                Name:  Richard H. Prokosch
                                Title: Vice President

                            ECHOSTAR SATELLITE OPERATING CORPORATION,
                             as New Guarantor

                            By:    /s/ David K. Moskowitz
                                ------------------------------------------------
                                Name:  David K. Moskowitz
                                Title: Senior Vice President

<PAGE>

                                                                       Exhibit A

                                    GUARANTEE

                  EchoStar Satellite Operating Corporation and its successors
under the Indenture, dated as of December 28, 2001 (the "Indenture"), among
EchoStar DBS Corporation (the "Company"), the Guarantors (as defined in the
Indenture, as supplemented) and U.S. Bank National Association (the "Trustee"),
for the 9 1.8% Senior Notes due 2008 (the "Notes") of the Company, jointly and
severally with any other Guarantors, hereby irrevocably and unconditionally
guarantees (i) the due and punctual payment of the principal of, premium, if
any, and interest on the Notes, whether at maturity, by acceleration or
otherwise, the due and punctual payment of interest on the overdue principal of
and interest, if any, on the Notes, to the extent lawful, and the due and
punctual performance of all other obligations of the Company to the Holders or
the Trustee all in accordance with the terms set forth in Article 10 of the
Indenture, (ii) in case of any extension of time of payment or renewal of any
Notes or any of such other obligations, that the same will be promptly paid in
full when due or performed in accordance with the terms of the extension or
renewal, whether at stated maturity, by acceleration or otherwise and (iii) has
agreed to pay any and all costs and expenses (including reasonable attorneys'
fees) incurred by the Trustee or any Holder in enforcing any rights under this
Guarantee. Capitalized terms used herein have the meanings assigned to them in
the Indenture, as amended and supplemented, unless otherwise indicated.

                  No stockholder, officer, director or incorporator, as such,
past, present or future, of EchoStar Satellite Operating Corporation shall have
any personal liability under this Guarantee by reason of his or its status as
such stockholder, officer, director or incorporator. This Guarantee shall be
binding upon EchoStar Satellite Operating Corporation and its successors and
assigns and shall inure to the benefit of the successors and assigns of the
Trustee and the Holders and, in the event of any transfer or assignment of
rights by any Holder or the Trustee, the rights and privileges herein conferred
upon that party shall automatically extend to and be vested in such transferee
or assignee, all subject to the terms and conditions hereof.

                  This Guarantee shall not be valid or obligatory for any
purpose until the certificate of authentication on the Note upon which this
Guarantee is noted shall have been executed by the Trustee under the Indenture
by the manual signature of one of its authorized officers.

                  THE TERMS OF ARTICLE 10 OF THE INDENTURE ARE INCORPORATED
HEREIN BY REFERENCE.

                  This Guarantee shall be governed by and construed in
accordance with the laws of the State of New York.

                                     ECHOSTAR SATELLITE OPERATING
                                     CORPORATION

                                     By:    /s/ David K. Moskowitz
                                            ----------------------
                                            Name:  David K. Moskowitz
                                            Title: Senior Vice President<PAGE>

                                                                    EXHIBIT 4.13

                            ECHOSTAR DBS CORPORATION

                          5 3/4% SENIOR NOTES DUE 2008

                          FIRST SUPPLEMENTAL INDENTURE

                          Dated as of December 31, 2003

                         U.S. Bank National Association

                                     Trustee

<PAGE>

                  FIRST SUPPLEMENTAL INDENTURE, dated as of December 31, 2003
(the "Supplemental Indenture"), among EchoStar DBS Corporation, a Colorado
corporation (the "Company"), EchoStar Satellite Operating Corporation, a
Colorado corporation (the "New Guarantor"), and U.S. Bank National Association,
as trustee (the "Trustee"), to the indenture, dated as of October 2, 2003 (the
"Original Indenture"), among the Company, the Guarantors (as defined in the
Original Indenture) and the Trustee, for the 5 3/4% Senior Notes due 2008 (the
"Notes") of the Company.

                                    RECITALS

                  The Company, the Guarantors and the Trustee have heretofore
executed and delivered the Original Indenture providing for the issuance of the
Notes.

                  The Company or one of the Guarantors has determined to
transfer property or assets to the New Guarantor.

                  Pursuant to Section 4.13 of the Original Indenture, the
Company and the New Guarantor have duly authorized the execution and delivery of
this Supplemental Indenture to provide for the addition of the New Guarantor to
the list of Guarantors under the Original Indenture.

                  New Guarantor has executed and delivers herewith the guarantee
(the "New Guarantee") attached hereto as Exhibit A.

                  All things necessary (i) to make the New Guarantee when
executed by the New Guarantor and delivered hereunder the valid obligations of
the New Guarantor and (ii) to make this Supplemental Indenture a valid agreement
of the Company and the New Guarantor, all in accordance with their respective
terms, have been done.

                  In consideration of the premises and the covenants and
agreements contained herein, and for other good and valuable consideration the
receipt of which is hereby acknowledged, it is mutually agreed as follows for
the equal and ratable benefit of the Holders of the Notes.

SECTION 1.        Additional Subsidiary Guarantee.

                  Pursuant to Section 4.13 of the Original Indenture, New
Guarantor is hereby made a party to the Original Indenture as a "Guarantor", and
as a "Guarantor" the New Guarantor unconditionally guarantees all of the
Company's obligations under the Notes on the terms set forth in the Original
Indenture.

SECTION 2.        Effect on the Original Indenture.

                  Except as amended by this Supplement Indenture, the Original
Indenture shall remain in full force and effect and is hereby ratified and
confirmed.

SECTION 3.        Governing Law.

                  The internal law of the State of New York shall govern and be
used to construe this Supplemental Indenture and the New Guarantee.

                                       1

<PAGE>

SECTION 4.        Defined Terms.

                  Unless otherwise indicated, capitalized terms used in this
Supplemental Indenture and not defined shall have the respective meanings
assigned to them in the Original Indenture.

SECTION 5.        Counterpart Originals.

                  The parties may sign any number of copies of this Supplemental
Indenture. Each signed copy shall be an original, but all of them together
represent the same agreement.

SECTION 6.        Effect of Headings.

                  Section headings herein are for convenience only and shall not
affect the construction hereof.

SECTION 7.        Severability.

                  In case any provision in this Supplemental Indenture shall be
invalid, illegal or unenforceable, the validity, legality and enforceability of
the remaining provisions shall not in any way be effected or impaired thereby.

                                       2

<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have caused this
Supplemental Indenture to be duly executed as of the day and year first above
written.

                                  ECHOSTAR DBS CORPORATION,
                                       a Colorado corporation

                                  By:      /s/ David K. Moskowitz
                                      ------------------------------------------
                                      Name:  David K. Moskowitz
                                      Title: Senior Vice President

                                  U.S. BANK NATIONAL ASSOCIATION,
                                       as Trustee

                                  By:      /s/ Richard H. Prokosch
                                      ------------------------------------------
                                      Name:  Richard H. Prokosch
                                      Title: Vice President

                                  ECHOSTAR SATELLITE OPERATING CORPORATION,
                                       as New Guarantor

                                  By:      /s/ David K. Moskowitz
                                      ------------------------------------------
                                      Name:  David K. Moskowitz
                                      Title: Senior Vice President

<PAGE>

                                                                       Exhibit A

                                    GUARANTEE

                  EchoStar Satellite Operating Corporation and its successors
under the Indenture, dated as of October 2, 2003 (the "Indenture"), among
EchoStar DBS Corporation (the "Company"), the Guarantors (as defined in the
Indenture, as supplemented) and U.S. Bank National Association (the "Trustee"),
for the 5 3/4% Senior Notes due 2008 (the "Notes") of the Company, jointly and
severally with any other Guarantors, hereby irrevocably and unconditionally
guarantees (i) the due and punctual payment of the principal of, premium, if
any, and interest on the Notes, whether at maturity, by acceleration or
otherwise, the due and punctual payment of interest on the overdue principal of
and interest, if any, on the Notes, to the extent lawful, and the due and
punctual performance of all other obligations of the Company to the Holders or
the Trustee all in accordance with the terms set forth in Article 10 of the
Indenture, (ii) in case of any extension of time of payment or renewal of any
Notes or any of such other obligations, that the same will be promptly paid in
full when due or performed in accordance with the terms of the extension or
renewal, whether at stated maturity, by acceleration or otherwise and (iii) has
agreed to pay any and all costs and expenses (including reasonable attorneys'
fees) incurred by the Trustee or any Holder in enforcing any rights under this
Guarantee. Capitalized terms used herein have the meanings assigned to them in
the Indenture, as amended and supplemented, unless otherwise indicated.

                  No stockholder, officer, director or incorporator, as such,
past, present or future, of EchoStar Satellite Operating Corporation shall have
any personal liability under this Guarantee by reason of his or its status as
such stockholder, officer, director or incorporator. This Guarantee shall be
binding upon EchoStar Satellite Operating Corporation and its successors and
assigns and shall inure to the benefit of the successors and assigns of the
Trustee and the Holders and, in the event of any transfer or assignment of
rights by any Holder or the Trustee, the rights and privileges herein conferred
upon that party shall automatically extend to and be vested in such transferee
or assignee, all subject to the terms and conditions hereof.

                  This Guarantee shall not be valid or obligatory for any
purpose until the certificate of authentication on the Note upon which this
Guarantee is noted shall have been executed by the Trustee under the Indenture
by the manual signature of one of its authorized officers.

                  THE TERMS OF ARTICLE 10 OF THE INDENTURE ARE INCORPORATED
HEREIN BY REFERENCE.

                  This Guarantee shall be governed by and construed in
accordance with the laws of the State of New York.

                                       ECHOSTAR SATELLITE OPERATING
                                       CORPORATION

                                       BY:    /S/ DAVID K. MOSKOWITZ
                                            ------------------------------------
                                            NAME:  DAVID K. MOSKOWITZ
                                            TITLE: SENIOR VICE PRESIDENT

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