Final, S2740 Respons

LETTER submitted by DISH Operating L.L.C.

Letter Response to 13 Sept Inquiry

2012-09-28

This document pretains to SAT-AMD-20100610-00127 for Amended Filing on a Satellite Space Stations filing.

IBFS_SATAMD2010061000127_967989

      Pantelis Michalopoulos
      202 429 6494
      pmichalopoulos@steptoe.com

      1330 Connecticut Avenue, NW
      Washington, DC 20036-1795
      202 429 3000 main
      www.steptoe.com




September 28, 2012

VIA IBFS

Marlene H. Dortch
Secretary
Federal Communications Commission
445 12th Street, SW
Washington, DC 20554

Re:       DISH Operating LLC; File Nos. SAT-MOD-20100329-00058, SAT-AMD-20100610-00127
          (Call Sign 2740)


Dear Ms. Dortch:

       With this letter, DISH Operating LLC (“DISH”) responds to the September 13, 2012 letter from
the Robert Nelson, Chief, Satellite Division of the International Bureau, requesting additional
information regarding EchoStar 7’s orbital debris mitigation plan. Specifically, the September 13th letter
asks DISH to identify each tank on the spacecraft that will not be vented or have its pressure relieved
upon disposal of the spacecraft, and for each such tank, provide:

          • the volume of the tank,
          • the propellants and/or pressurants left in the tank, identified by their chemical names,
          • the mass of each propellant or pressurant left in the tank,
          • the expected maximum internal temperature of the tank in the disposal orbit, and
          • the expected maximum internal pressure of the tank in the disposal orbit.

The letter also asks DISH to explain whether the oxidizer tanks are currently sealed or unsealed, and if
the tanks were sealed, to indicate when they were sealed, and if the tanks were not sealed, to state when
they will be sealed. Finally, the letter asks whether the analysis of disposal options outlined for the
EchoStar 4 satellite in IBFS File No. SAT-STA-20110627-00122 is also applicable with respect to
EchoStar 7.


Marlene H. Dortch
September 28, 2012
Page 2


       There are four tanks on the EchoStar 7 satellite that will not be vented to depletion at spacecraft
end-of-life (“EOL”). These four tanks and their relevant data are as follows:

                                                                                                               Max Internal
                                                                                        Max Internal
                     Tank Volume Propellant/                 Mass Remaining                                      Pressure,
       Tank                                                                            Temp, Disposal
                         (in3)   Pressurant                       (kg)                                           Disposal
                                                                                         Orbit (C)
                                                                                                               Orbit (psia)1
Oxidizer             20,017.5             N2O4             39.8 (amount                35                      295
Tank #1                                                    remaining between
Oxidizer             20,015.2             N2O4             the 2 oxidizer              35                      295
Tank #2                                                    tanks)2
Pressurant           4,234.8              He               0.558 (amount               35                      500
Tank #1                                                    remaining between
Pressurant           4,242.4              He               the 2 pressurant            35                      500
Tank #2                                                    tanks)3
1
    These pressures are far below the respective margins for the burst pressure for these tanks.
2
    Relatively efficient orbit raising resulted in slightly larger-than-expected-amounts of remaining oxidizer on the spacecraft.
3
 The remaining gaseous Helium is a residual amount expected to persist after the final repressurization of the hydrazine tank
before EOL maneuvers.

       The oxidizer tanks were sealed with pyrotechnic valves upon completion of in-orbit testing on
March 7, 2002. DISH expects EchoStar 7 to provide a full lifetime of commercial service, leaving only
enough remaining hydrazine, with appropriate margins, to achieve the disposal orbit of 350 km
minimum perigee. The above figures for the oxidizer and pressurant tanks represent the estimated
values expected upon completion of all EOL procedures.

           Please let me know if you have further questions.


                                                                   Respectfully submitted,

                                                                                /s/

                                                                   Pantelis Michalopoulos
                                                                   Counsel for DISH Operating LLC

cc:        Kathyrn Medley, FCC
           Karl Kensinger, FCC
           Howard W. Waltzman, Mayer Brown LLP
           David Wilson, Spectrum Five LLC



Document Created: 2012-09-28 15:21:55
Document Modified: 2012-09-28 15:21:55

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