SUPPLEMENTAL INDENTURE

Exhibit 4.3

SUPPLEMENTAL INDENTURE

THIS SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), entered into as of June 8, 2011, among EH Holding Corporation., a Colorado corporation (the “Company”), the guarantors listed on the signature pages to the Unsecured Indenture (the “Guarantors”), Xxxxxx Communications, Inc., (“Xxxxxx”, and together with the other additional guarantors listed on the signature pages hereto, the “Supplemental Guarantors”), and Xxxxx Fargo Bank, National Association., as trustee (the “Trustee”).  Capitalized terms used herein and not otherwise defined herein are used as defined in the Unsecured Indenture referred to below.

RECITALS

WHEREAS, EH Holding Corporation, a Colorado corporation, the Guarantors listed on the signature pages thereto and the Trustee entered into that certain Unsecured Indenture, dated as of June 1, 2011 (the “Unsecured Indenture”), relating to the 75/8% Senior Unsecured Notes due 2021 in original principal amount of $900,000,000 (the “Unsecured  Notes”).

WHEREAS, on the date hereof, the Acquisition has been consummated and each of the Supplemental Guarantors is a Restricted Subsidiary of the Company; and

WHEREAS, pursuant to Section 4.13 and Section 4.22(b) of the Indenture, each Supplemental Guarantor is required to become a Guarantor under the Unsecured Indenture; and

AGREEMENT

NOW, THEREFORE, the parties to this Supplemental Indenture hereby agree as follows:

Section 1.               Each Supplemental Guarantor shall be a Guarantor under the Unsecured Indenture and be bound by the terms thereof applicable to Guarantors and each shall deliver an executed Guarantee pursuant to Section 10.02.

Section 2.               This Supplemental Indenture is an amendment supplemental to the Unsecured Indenture, and the Unsecured Indenture and this Supplemental Indenture will henceforth be read together.

Section 3.               This Supplemental Indenture shall be governed by and construed in accordance with the laws of the State of New York.

Section 4.               This Supplemental Indenture may be signed in various counterparts which together will constitute one and the same instrument.

The exchange of copies of this Supplemental Indenture and of signature pages by facsimile or PDF transmission shall constitute effective execution and delivery of this Supplemental Indenture as to the parties hereto and may be used in lieu of the original Supplemental Indenture for all purposes.  Signatures of the parties hereto transmitted by facsimile or PDF shall be deemed to be their original signatures for all purposes.

[Signature pages follow]

	EH HOLDING CORPORATION
	By:	/s/ Xxxxxxx X. Xxxxx
		Name: Xxxxxxx X. Xxxxx
		Title: President and Chief Executive Officer
	ECHOSTAR 77 CORPORATION
	ECHOSTAR SATELLITE SERVICES L.L.C.
	ECHOSTAR ORBITAL L.L.C.
	ECHOSTAR GOVERNMENT SERVICES L.L.C.
	ECHOSTAR SATELLITE OPERATING CORPORATION,
	as Guarantors
	By:	/s/ Xxxxxxx X. Xxxxx
		Name: Xxxxxxx X. Xxxxx
		Title: President and Chief Executive Officer
	XXXXXX COMMUNICATIONS, INC.,
	as a Supplemental Guarantor
	By:			/s/ Xxxx X. Xxxxxx
	Name:			Xxxx Xxxxxx
	Title:			Senior Vice President, General Counsel and Secretary
	XXXXXX NETWORK SYSTEMS, LLC,
	as a Supplemental Guarantor
	By:		/s/ Xxxx X. Xxxxxx
	Name:		Xxxx Xxxxxx
	Title:		Senior Vice President, General Counsel and Secretary

2

	HNS FINANCE CORP.,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Vice President, General Counsel and Secretary
	XXXXXX NETWORK SYSTEMS INTERNATIONAL SERVICE COMPANY,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Vice President, General Counsel and Secretary
	HNS REAL ESTATE, LLC,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Vice President, General Counsel and Secretary
	HNS-INDIA VSAT, INC.,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Vice President, General Counsel and Secretary

3

	HNS-SHANGHAI, INC.,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Vice President, General Counsel and Secretary
	HELIUS, LLC,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Secretary
	HELIUS ACQUISITION, LLC,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Secretary
	ADVANCED SATELLITE RESEARCH, LLC,
	as a Supplemental Guarantor
	By:	/s/ Xxxx X. Xxxxxx
	Name:	Xxxx Xxxxxx
	Title:	Secretary

4

	HNS LICENSE SUB, LLC,
	as a Supplemental Guarantor
	By: Xxxxxx Network Systems, LLC, its Sole Member
	By:		/s/ Xxxx X. Xxxxxx
	Name:		Xxxx X. Xxxxxx
	Title:		Senior Vice President, General Counsel and Secretary
	XXXXX FARGO BANK, NATIONAL ASSOCIATION, as Trustee
	By:	/s/ Xxxxxxx Xxxxxxxx
		Name: Xxxxxxx Xxxxxxxx
		Title: Vice President

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