Attachment Technical Annex

This document pretains to SAT-AMD-20151221-00084 for Amended Filing on a Satellite Space Stations filing.

IBFS_SATAMD2015122100084_1119287

                                             ECHOSTAR-15

                                            ATTACHMENT A
                   Technical Information to Supplement Schedule S



A.1        Scope


This attachment contains the information required by §25.114(c) and other sections of the FCC
Part 25 rules that cannot be captured by the Schedule S form.


A.2        General Description of Overall System Facilities, Operations and Services
           (§25.114(d)(1))


The ECHOSTAR-15 satellite will serve as in-orbit spare in the EchoStar fleet at 61.65° W.L.,
collocated with the ECHOSTAR-16, ECHOSTAR-12 and ECHOSTAR-3 satellites. The satellite
will be operated using only TT&C frequencies located at the upper and lower 12 MHz
guardbands of the ITU’s Region 2 BSS Plan (Article 2A of Appendices 30 and 30A)1. EchoStar
is not seeking authority to operate the communications payload of ECHOSTAR-15 while located
at 61.65° W.L.


Primary TT&C functions will take place from EchoStar’s earth station and satellite control
facilities located in Cheyenne, WY and Gilbert, AZ.




1
    The ITU Region 2 BSS Plan frequencies used for space operations functions (TT&C) are 12.2-12.212, 12.688-
    12.7, 17.3-17.312 and 17.788-17.8 GHz.


A.3     TT&C Characteristics
        (§25.114(c)(4)(i) and §25.114(c)(9))


The information provided in this section complements that provided in the associated Schedule S
submission.


The ECHOSTAR-15 TT&C subsystem provides for communications during transfer orbit and
on-station operations, as well as during spacecraft emergencies. The TT&C subsystem operates
in the 12 MHz guardbands for both uplink and downlink during all phases of the mission. The
TT&C subsystem consists of 6 near omni-directional command antennas, 4 near omni-
directional telemetry antennas, and 2 Ku-band communication antennas that can receive
commands and transmit telemetry. TT&C operations will be conducted from EchoStar’s
Cheyenne, WY and Gilbert, AZ facilities. Other EchoStar TT&C facilities in Blackhawk, SD
and Mt. Jackson, VA may be used in the event of an emergency or contingency requirement,
subject to obtaining additional, appropriate FCC authorization in the future. The spacecraft is
capable of operating at two command frequencies shown in Table A-1 below. During normal on-
station and emergency operations at 61.65° W.L, command signals will be received by the near
omni-directional antennas. The spacecraft is capable of operating at four transmit frequencies
shown in Table A-1 below. During normal on-station and emergency operations at 61.65° W.L.,
the telemetry signals will be transmitted by the near omni-directional antennas.


A summary of the TT&C subsystem characteristics is given in Table A-1.


                         Table A-1: TT&C Performance Characteristics
   Command Modulation                                                 PCM/PSK

                                                                    17,791.5 MHz
   Command/Ranging Frequencies
                                                                    17,793.5 MHz

                                                    Omni Rx antenna: >  -83 dBW/m2 (Command)
   Uplink Flux Density (Minimum)                                        -78 dBW/m2 (Ranging)
                                                    Comms Rx antenna: > -93 dBW/m2 (Command)
                                                                        -87 dBW/m2 (Ranging)
                                                    Omni antenna during transfer orbit and on-station
   Satellite Receive Antenna Types                  emergencies for telecommand.
   and Modes of Operation                           Communications antenna during normal on-station
                                                    operations for telecommand.


   Polarization of Satellite Rx/Tx Antennas         RHCP for omni antenna
                                                    RHCP for communications antenna
   Peak Deviation (Command/Ranging)                                   ± 400 kHz

                                                                    12,692.0 MHz
   Telemetry/Ranging Frequencies                                    12,693.0 MHz
                                                                    12,694.5 MHz
                                                                    12,698.5 MHz
   Satellite Transmit Antenna Types                 Omni antenna during transfer orbit, on-station
                                                    emergencies and normal on-station operations for
   and Modes of Operation
                                                    telemetry.

   Maximum Downlink EIRP                            15.2 dBW (Omni antenna)
                                                    18 dBW (Communications antenna)
   Telemetry/Ranging Modulation Index:
         1 sub-carrier                                             1.0 ± 0.2 rad pk
         2 sub-carriers                                            0.7± 0.2 rad pk
         3 sub-carriers                                            0.58± 0.2 rad pk



A.4     Orbital Debris Mitigation Plan
        (§25.114(d)(14))


A.4.1   Debris Release Assessment
        (§25.144(d)(14)(i))

To protect the spacecraft from small body collisions, the design of the ECHOSTAR-15
spacecraft allows for individual faults without losing the entire spacecraft. All critical
components (i.e., computers and control devices) have been built within the structure and
shielded from external influences. Items that could not be built within the spacecraft nor shielded
(such as antennas) are redundant and/or are able to withstand impact. The ECHOSTAR-15
spacecraft can be controlled through both the normal payload antenna and wide angle antennas.
The likelihood of both being damaged during a small body collision is minimal. The wide angle
antennas on this spacecraft are basically open waveguides that point towards the Earth (there is
one set on each side of the spacecraft; either set could be used to successfully de-orbit the
spacecraft). These wide angle antennas would continue to operate even if struck and bent.


Based on the above structural design and critical component redundancy, EchoStar believes this
satellite has a limited probability of becoming a source of debris from small body collisions.


A.4.2     Accidental Explosion Assessment
          (§25.144(d)(14)(ii))

In order to ensure that the spacecraft does not explode on orbit the satellite controller takes
specific precautions. All batteries and fuel tanks are monitored for pressure or temperature
variations. Alarms in the Satellite Control Center (“SCC”) inform controllers of any variations.
Additionally, long term trending analysis will be performed to monitor for any unexpected
trends.


Operationally, batteries are operated utilizing the manufacturer’s automatic recharging scheme.
Doing so ensures that charging terminates normally without building up additional heat. As this
process occurs wholly within the spacecraft, it also affords protection from ground command
link failures.


In order to protect the propulsion system, fuel tanks have been operated in a “blow down” mode.
This means that at the completion of the orbit raising phase of the mission, the pressurant was
isolated from the fuel system, thereby causing the pressure in the tanks to decrease over the life
of the spacecraft. This also protects against a pressure valve failure causing the fuel tanks to
become over pressurized.


In order to ensure that the spacecraft has no explosive risk after it has been successfully de-
orbited, all stored energy onboard the spacecraft will be removed. Upon successful de-orbit of
the spacecraft, all propulsion lines and latch valves will be vented and left open. All battery
chargers will be turned off and batteries will be left in a permanent discharge state. These steps
will ensure that no buildup of energy can occur resulting in an explosion in the years after the
spacecraft is de-orbited.


Based on the above structural design and planned flight control precautions during and after the
mission completion, EchoStar believes this satellite has a limited probability of becoming a
source of debris from accidental explosions.


A.4.3   Safe Flight Profiles
        (§25.144(d)(14)(iii))

In considering current and planned satellites that may have a station-keeping volume that
overlaps the ECHOSTAR-15 satellite, EchoStar has reviewed the lists of FCC-licensed satellite
networks, as well as those that are currently under consideration by the FCC. In addition, non-
U.S. networks for which a request for coordination has been published by the International
Telecommunication Union (“ITU”) within ±0.15° of 61.65° W.L. have been reviewed.


As already mentioned, the ECHOSTAR-16, ECHOSTAR-12 and ECHOSTAR-3 satellites
operate at the nominal 61.65° W.L. orbital location, each having an east-west station-keeping
tolerance of ±0.05°. These satellites are operated by EchoStar and can be internally coordinated
to ensure their safe operation.


There are no pending applications before the Commission to use an orbital location within
±0.15° from 61.65° W.L. EchoStar is not aware of any satellite with an overlapping station-
keeping volume with the ECHOSTAR-15 satellite and that is either in orbit or progressing
towards launch pursuant to an ITU filing.


Based on the preceding, EchoStar seeks to locate and operate the ECHOSTAR-15 satellite at
61.65° W.L., with an east-west station-keeping tolerance of ±0.05°, in order to eliminate the
possibility of any station-keeping volume overlap with the adjacent EchoStar satellites. EchoStar
therefore concludes that physical coordination of the ECHOSTAR-15 satellite with another party
is not required at the present time.


A.4.4   Post Mission Disposal Plan
        (§25.144(d)(14)(iv))

At the end of the operational life of the ECHOSTAR-15 satellite, EchoStar will maneuver the
satellite to a disposal orbit with a minimum perigee of 330 km above the normal GSO
operational orbit. This proposed disposal orbit altitude exceeds the minimum required by
§25.283, which is calculated below.

The input data required for the calculation is as follows:


       Total Solar Pressure Area “A” = 111 m2
       (includes area of solar array, satellite body and deployed antennas)
       “M” = Dry Mass of Satellite = 2364 kg
       “CR” = Solar Pressure Radiation Coefficient (worst case) = 2


Using the formula given in §25.283, the Minimum Disposal Orbit Perigee Altitude is calculated
as follows:

               =      36,021 km + 1000 x CR x A/M
               =      36,021 km + 1000 x 2 x 111/2364
               =      36,115 km
               =      329 km above GSO (35,786 km)

Adequate margin has already been accounted for in the calculation of the designed disposal orbit
of 330 km above GSO, which includes margin relative to the above calculation. Attaining the
altitude of 330 km above the GSO orbit will require approximately 12 kg of propellant, which
will be reserved, taking account of all fuel measurement uncertainties, to perform the final orbit
raising maneuvers.


Propellant tracking is accomplished using a bookkeeping method. Using this method, the ground
control station tracks the number of jet seconds utilized for station keeping, momentum control
and other attitude control events. From the number of jet seconds, the amount of fuel used is
determined. This process has been calibrated using data collected from thruster tests conducted
on the ground and has been found to be accurate to within a few months of life on the spacecraft.


In addition to the bookkeeping method, a pressure, volume and temperature (PVT) test is done to
support the findings of the bookkeeping method. Lastly, propellant depletion gauges allow for
monitoring of the propellant through the telemetry.


A.5     Interference Analysis


The ECHOSTAR-15 satellite at 61.65° W.L. will operate under authority of the United States. The
underlying Article 2A satellite network filing, USABSS-17, which has been recorded in the Master
International Frequency Register (MIFR) at the nominal location of 61.5° W.L.


EchoStar is not seeking operating authority of the communications payload on ECHOSTAR-15.
Accordingly, no interference analysis is provided for the operations of the communication payload.


The next adjacent satellites with potential TT&C frequency overlap with ECHOSTAR-15 are
NIMIQ-5 (nominally located at 72.7° W.L., 11.1° away) and INTELSAT 805 (nominally located
at 55.5° W.L., 6° away). Given this large orbital separation and the use of large earth stations for
both command and telemetry, negligible interference will be received from them or caused by the
ECHOSTAR-15 satellite.



                           ___________________________________


              CERTIFICATION OF PERSON RESPONSIBLE FOR PREPARING
                          ENGINEERING INFORMATION




       I hereby certify that I am the technically qualified person responsible for preparation of

the engineering information contained in this application, that I am familiar with Part 25 of the

Commission’s rules, that I have either prepared or reviewed the engineering information

submitted in this application and that it is complete and accurate to the best of my knowledge

and belief.




                                              /s/ Zachary Rosenbaum
                                              Zachary Rosenbaum
                                              Senior Manager, Advanced Programs and Spectrum
                                              Management



Document Created: 2019-04-12 02:17:36
Document Modified: 2019-04-12 02:17:36

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