Tyvak0129 Narrative v2

0987-EX-CN-2018 Text Documents

Tyvak Nano-Satellite Systems

2018-12-11ELS_221017

                                 Before the
                   FEDERAL COMMUNICATIONS COMMISSION
                            Washington, DC 20554



In the Matter of                       )
                                       )
Tyvak Nano-Satellite Systems Inc.      )
                                       )
Application for Authority for Ground   )
Testing, Launch, and Operation of      )   File No. 0987-EX-PL-2018
Experimental Non-Geostationary         )
Low Earth Orbit Satellites             )




                             NARRATIVE EXHIBIT


                                         Table of Contents

I.    NARRATIVE INFORMATION REQUIRED BY FCC FORM 442 ................. 2
               Question 6A. Description of the nature of the research project
                            being conducted ............................................................... 2
               Question 6B. Showing that the communications facilities
                            requested are necessary for the research project .............. 3
               Question 6C. Showing that existing communications facilities are
                            inadequate ........................................................................ 4
               Question 10. Transmitting equipment to be installed, including
                            manufacturer, model number and whether the
                            equipment is experimental in nature ................................ 5
               Question 11A. Is the equipment listed in Item 10 capable of station
                             identification pursuant to Section 5.115 .......................... 8
               Question 4.         Antenna Registration Form. Operation of
                                   Directional Antenna ......................................................... 8
II.   RELEVANT INFORMATION ADDRESSED IN SECTION 25.114 OF
      THE COMMISSION’S RULES .......................................................................... 9
               Section 25.114(c)(4)(1) Radio Frequency Plan ....................................... 9
               Section 25.114(c)(5)(1) Orbital Locations ............................................ 17
               Section 25.114(c)(10) Physical Characteristics of Satellites ................. 18
               Section 25.114(c)(12) Schedule............................................................. 20
               Section 25.114(d)(1) General Description of Overall System
                             Facilities, Operations and Services ................................ 20
               Section 25.114(d)(3) Predicted Spacecraft Antenna Gain Contours ..... 21
               Section 25.114(d)(14) Orbital Debris Mitigation .................................. 23
               Section 25.114(d)(14)(i) Limiting the amount of debris released
                             during normal operations and the probability of the
                             satellite becoming a source of debris by collisions
                             with small debris or meteoroids that could cause
                             loss of control and prevent post-mission disposal ......... 23
               Section 25.114(d)(14)(ii) Limiting the probability of accidental
                             explosions during and after completion of the
                             mission operations ......................................................... 24
               Section 25.114(d)(14)(iii) Limiting the probability of the satellite
                             becoming a source of debris by collisions with large
                             debris or other operational space stations ...................... 25


                 Section 25.114(d)(14)(iv) Post-mission disposal plans for the space
                               station at end of life ....................................................... 25
III.   CONCLUSION.................................................................................................. 26




                                                         ii


                                   Before the
                     FEDERAL COMMUNICATIONS COMMISSION
                              Washington, DC 20554


 In the Matter of                               )
                                                )
 Tyvak Nano-Satellite Systems Inc.              )
                                                )    File No. 0987-EX-PL-2018
 Application for Authority for Ground           )
 Testing, Launch, and Operation of              )
 Experimental Non-Geostationary                 )
 Low Earth Orbit Satellites                     )


                                    NARRATIVE EXHIBIT

       Tyvak Nano-Satellite Systems Inc. (“Tyvak”) provides nano-satellite, micro-satellite, and

CubeSat space vehicle products and services that target advanced state-of-the-art capabilities for

government and commercial customers to support operationally and scientifically relevant

missions.   With this Application, Tyvak requests two-year authority for operation of an

experimental non-geostationary (“NGSO”) low earth orbit (“LEO”) CubeSat satellite referred to

as Tyvak-0129. The RF communications links for the satellite will be two-way telemetry

monitoring and command (“T&C”) transmissions in the 400 MHz UHF range and space-to-Earth

downlink transmissions in the 2 GHz S-band range.


I.     NARRATIVE INFORMATION REQUIRED BY FCC FORM 442

Question 6A. Description of the Nature of the Research Project Being Conducted

       Through the Tyvak-0129 satellite, Tyvak validates the spacecraft bus technologies needed

to support the development of the Pathfinder experimental flight vehicle being built by Tyvak in

cooperation with NASA. The NASA Pathfinder program leverages the inherent low costs of


CubeSat vehicle manufacture and launch capabilities to host experimental payloads (from payload

vendors selected by NASA) for testing, flight training and on-orbit demonstrations.

       Tyvak-0129 seeks to gather in-flight data for the bus hardware platform as a risk reduction

prior to the NASA Pathfinder mission. The Tyvak-0129 bus platform includes the next generation

of Tyvak power, communication, GNC and on-board processing subsystems and will be identical

in form, fit and function to the bus used on NASA Pathfinder. Subsequently, Tyvak-0129 will

serve as a flight demonstration to reduce risk and provide flight heritage to the bus platform prior

to the launch of the NASA Pathfinder experimental missions later in 2019.

       The NASA Pathfinder spectrum application has already been filed and an NTIA

Certification of Spectrum Support has already been granted (NTIA Document 43771/1 SPS-

23289/1). As such, Tyvak-0129 seeks to use the same UHF/S-band spacecraft configuration and

the same UHF/S-band ground assets to enrich the level of risk-reduction provided to NASA

Pathfinder.

       In addition, Tyvak-0129 will host two experimental payloads to increase their technology

readiness level and gather valuable flight test data. The two payloads are an electric propulsion

system developed by Accion Systems Inc (“Accion”) and a receive-only radio system developed

by the Lockheed Martin Corporation (“LM”). Both payloads are only powered by Tyvak-0129 and

rely on the spacecraft bus to downlink all flight telemetry to ground assets.

       The satellites will adhere to a design specification co-developed by California State

University, San Luis Obispo (“Cal Poly”) and Stanford University (“Stanford”) referred to as the

CubeSat Standard. Additional information regarding the CubeSat Standard can be found at the

CubeSat Community website, http://www.CubeSat.org/.




                                                 2


       The spacecrafts will be fabricated, tested, launched, and operated by Tyvak using its

Mission Operations Center (“MOC”) in Irvine, California, and using affiliated Earth stations in

the Continental United States (CONUS) and internationally. T&C for the satellites will be carried

out by Tyvak via a two-way link in the UHF band with Telemetry between 400.15-401 MHz and

Command between 401 to 402MHz. Both payloads will relay test instrument data via the

spacecraft bus communication system to Tyvak-affiliated Earth stations using spectrum in the S-

band between 2200-2290 MHz. Additionally, the LM payload will have receive-only

communications capability separate from the T&C communications system to gather experimental

operations data. LM has separately filed for ground station licensing under FCC File No. 0843-

EX-CN-2018 to communicate from LM ground assets to their payload hosted on Tyvak-0129.

       The Tyvak-0129 satellite will be launched into orbit on April 2018 on a PSLV from

Sriharikota, India. The satellite is anticipated to perform operations for approximately 2 years. The

Tyvak-0129 satellite requests authority through the FCC to grant ground communication authority

to the satellite through CONUS ground stations.

Question 6B. Showing that the Communications Facilities Requested are Necessary for the
             Research Project

       The primary purpose of Tyvak’s CubeSat program is to test and demonstrate new satellite

capabilities or subsystems. On-orbit operation is the only effective way of collecting functional

and performance data in the relevant operational environment and cannot be adequately substituted

by ground testing or computer simulation.

       With the proliferation of the CubeSat Standard and the availability of low-cost space access

for those adhering to that standard, the cost to test miniature components on-orbit has become

relatively inexpensive compared to equivalent ground testing and simulation. This is largely due


                                                  3


to the availability of low-cost secondary payload launch options and cost sharing among multiple

CubeSat developers.

       In addition, on-orbit data provides confidence to customers that future systems will operate

successfully on-orbit through maneuvers.        The evaluation of hardware and software in an

environment similar to that found in space is not easily replicated on Earth. On-orbit component

failures are often attributed to unforeseen conditions or coupling of effects that cannot be tested

adequately until on-orbit. Consequently, the use of an on-orbit test bed provides significant direct

and indirect financial benefits, as well as risk reduction for future satellite programs.

Question 6C. Showing that Existing Communications Facilities are Inadequate

       The ground stations that would be used for operations are established for T&C operations

within the 400-402 MHz UHF band.

       For the payload downlink in the 2,200-2,290 MHz S-band, the payload data must be

downlinked directly from the satellites to pre-existing KSAT Earth stations using these frequencies

and thus no alternative existing facilities will be adequate.

Question 10. Transmitting Equipment to be Installed, Including Manufacturer, Model
             Number and Whether the Equipment is Experimental in Nature

       Each of the CubeSats has capabilities for T&C and payload downlink.                  Spacecraft

telemetry downlink is carried out in the UHF band between 400.15-401 MHz and uplink

commands are handled in the UHF band between 401-402MHz. Payload downlink is carried out

through an S-band transmitter in the range of 2200-2900 MHz. The following graphic provides

an overview of the transmitting and receiving components of each element. The specific model

numbers are subject to change based on product availability and system upgrades.




                                                  4


                  Figure 1: Mission Communication Systems Components

       The transmitting components aboard the CubeSats are controlled by a dedicated on-board

processor, which processes data for transmission, sends and receives data from the modem, and

activates the appropriate radio systems depending on the state of operations. Each vehicle

possesses a UHF system for vehicle command and telemetry retrieval and an S-band system for

payload data download.

       The T&C communications system uses a Tyvak-developed UHF radio derived from

commercially-available UHF communications systems. The radio operates at 19,200 baud using

GMSK. Tyvak-0129 will be the first flight experimental demonstration of the Tyvak-developed


                                              5


UHF radio and will be baselined for use in many of Tyvak’s future programs. The UHF system

will use a custom designed half-wave dipole antenna.

       The payload downlink S-band system utilizes an experimental Tyvak-developed S-band

radio and a patch antenna developed by Haigh-Farr. Similar to the UHF radio, Tyvak-0129 will be

the maiden flight of the Tyvak-developed S-band radio and serve as an on-orbit experimental

demonstration of its performance. In addition, a commercial off-the-shelf Quasonix transmitter

will also be used as a secondary S-band downlink and use an identical but independent Haigh-Farr

patch antenna. As both S-band radios use the same center frequency and bandwidth allocation,

they are not intended to be operated simultaneously.

       S-Band transmissions are completed with blind downlinks and the vehicle does not

transmit S-Band unless commanded by the ground to enable based on the ground station’s GPS

location or via absolute time. A 2 Mbps BPSK data rate is supported between the S-Band patch

antenna to a 3.7m dish on the ground with a transmit power of 2W. The antenna is RHCP with a

gain greater than 5dBic at the boresight with a VSWR < 2:1. The Tyvak S-band radio is also

capable of operating in GMSK modulation.

Question 11A. Is the Equipment Listed in Item 10 Capable of Station Identification
              Pursuant to Section 5.115

       Each transmitting component of the system is capable of station identification at the end of

each complete transmission. The station identification process is incorporated into the mission

operations procedure. The ground component will broadcast in clear voice the assigned call sign

at the end of each data transmission by ground station operators.


Question 4:    Antenna Registration Form; Operation of Directional Antenna



                                                6


         Tyvak-0129 will be a low earth orbit (“LEO”) satellite in a 500km sun-synchronous orbit

with an orbit period of approximately 1.6 hours. The satellite will pass over the Earth station

roughly one to twelve times per day depending on its location with an average access time of five

to nine minutes for each Earth station location. The UHF Earth station will use a computer-

controlled tracking antenna to point the Earth station’s antenna in the direction of the moving

satellites. The antenna has a maximum gain of +20.2dBi along the bore-sight of the antenna and

a half-power beam-width (i.e., -3dB) of approximately 30 degrees. The antenna array uses four

off-the-shelf, Yagi-type antennae developed by M2 Antenna Systems, Inc.

         Tyvak-0129 is a NGSO satellite, thus the range of antenna azimuth and elevation will vary

based on the relative motion of the satellite with respect to the ground station. It will also differ

for each satellite pass. The Earth station will only transmit above the horizon. Consequently, the

range of antenna elevation angles for all satellite passes will be between 0 and 180 degrees. The

azimuth can vary between 0 degrees and 360 degrees.

         In addition to on-orbit operations, the satellite components will undergo developmental

testing at Tyvak’s Irvine, CA facility beginning in December of 2018. Testing for the UHF TT&C

link will be conducted in carrier current (i.e., closed-loop) configuration and will produce only

unintentional emissions. Under the Commission’s rules, unintentional radiators operating in the

frequency range between 9 kHz to 30 MHz must comply with the radiated emission limits for

intentional radiators as provided in 47 C.F.R. § 15.209. 1 As Tyvak’s test program may marginally

exceed these limits, Tyvak seeks experimental authority for emissions in the appropriate ranges at

the Tyvak facility. These developmental tests are expected to begin in December 2018.




1
    47 C.F.R. § 15.109(e).
                                                 7


II.    RELEVANT INFORMATION ADDRESSED IN SECTION 25.114 OF THE
       COMMISSION’S RULES

Section 25.114(c)(4)(i) Radio Frequency Plan

UHF Communications System

       Tyvak-0129’s      UHF     communications       system   will   operate   using   half-duplex

communications within the 401-402 MHz frequency band for telecommand (i.e., earth-to-space)

and 400.15-401 MHz frequency band for telemetry (i.e., space-to-earth) communications. Tyvak-

0129 is performing Earth Exploration payload technology demonstrations and thus the

use/categorization of the telecommand (i.e., earth-to-space) communications as an earth

exploration satellite is justified in both the US and international allocation for the 401-402 MHz

range. Similarly, Tyvak-0129 is utilizing UHF for vehicle telemetry downlink and thus the

use/categorization of the telemetry (i.e., space-to-earth) communications as space operation

(space-to-earth) is justified in both the US and international allocation for the 400.15-401 MHz

range. The space vehicle UHF communication system is half-duplex and, as such, the similar UHF

center frequency for both telecommand and telemetry poses no operational concern.

Space-to-Earth and Earth-to-Space UHF Communications

       Tyvak-0129 have been designed to include several precautions to prevent harmful

interference to other services from space-to-Earth transmissions. First, as noted above, space-to-

Earth satellite transmissions will be controlled from the Earth station and the spacecraft will not

transmit until it receives a request from the Earth station.

       Second, the satellite uplink and downlink will use the same 28.8 kHz bandwidth in half-

duplex mode to send digital data using standard GMSK modulation with maximum data rates up

to 19,200 baud.


                                                  8


          The satellite transmitter can be adjusted to provide up to two watts of power output when

communicating with the Earth station. Transmission power on the Earth station transmitter can be

adjusted to provide up to 200 watts of power output. The communications parameters for the UHF

communications system for the space-to-Earth and Earth-to-space links are shown in the following

tables.

                    CubeSat Communications            Value
                    Parameters
                    Emission Designator               28K8G1D
                    Service                           Digital Data
                    Center Frequency                  400.74 MHz
                    Requested Bandwidth               28.8 kHz
                    (includes Doppler)
                    Modulation                        GMSK
                    Data Rate                         19,200 bps
                    Polarization                      Linear (Results in RHCP)
                    Antenna Type                      Dipole
                    Antenna Gain                      0 dBi (Max)
                    RF Power Output                   2W
                    Line/Misc Losses                  -2dB
                    EIRP                              1.0 dBW
                            Table 1: Tyvak-0129 UHF Communications
                                   Space-to-Ground Parameters


                Earth Station Communications          Value
                Parameters
                Emission Designator                   28K8G1D
                Service                               Digital Data
                Center Frequency                      401.205 MHz
                Requested Bandwidth                   28.8 kHz
                (includes Doppler)
                Modulation                            GMSK
                Data Rate                             19,200 bps
                Polarization                          Linear (H, V) or Circular
                Antenna Type                          Yagi array
                Antenna Gain                          +20.2 dBi (Max)
                RF Power Output                       200 W
                Line Losses                           -3dB
                EIRP                                  40.2 dBW

                                                  9


               Table 2: Tyvak Earth Station UHF Communications Parameters




 Earth Station                     Frequency Range                Geographic Coordinates
 San Diego, CA, USA                UHF                            32.897°Lat, -117.201°Long
 Bardufoss, Norway                 UHF                            69.05°Lat, 18.48°Long
 Benevento, Italy                  UHF                            41.115°Lat, 14.826°Long
 Fairbanks, AK, USA                UHF                            64.85°Lat, -147.68°Long
                             Table 3: Tyvak Earth Stations UHF

S-Band Communications System

       The spacecraft’s S-band communications system will operate using simplex

communications within the 2200-2290 MHz frequency band to downlink recorded payload data

to Tyvak-affiliated S-band Earth stations. The Tyvak UHF Earth station at the Irvine MOC or

Tyvak-affiliated UHF stations at other locations will issue commands in the UHF-band to trigger

the satellite to transmit payload data in the S-band when over an S-Band KSAT site. The Tyvak

MOC will have no transmission or reception capabilities in the S-band.

                    CubeSat                    Value
                    Communications
                    Parameters
                    Emission Designator        2M80G1D
                    Service                    Digital Data
                    Center Frequency           2235 MHz
                    Requested Bandwidth        2.8 MHz
                    Modulation                 BPSK
                                               (Capable of GMSK)
                    Data Rate                  2 Mbps
                    Polarization               RHCP
                    Antenna Type               Patch
                    Antenna Gain               +2 dBic (Max)
                    RF Power Output            2W
                    Line Losses                -2dB
                    EIRP                       3 dBW
                Table 4: Tyvak CubeSat S-Band Communications Parameters


                                              10


 Earth Station                          Frequency Range             Geographic Coordinates
 Svalbard, Norway                       S-Band                      78.23°Lat, 15.39°Long
                              Table 5: Tyvak Earth Stations S-Band

       The CubeSats will communicate with the UHF ground stations and S-band ground stations

only when they are within line-of-sight of the Earth stations and have received a communication

from the Earth station directing the spacecraft to initiate transmissions.      Consequently, the

spacecrafts will utilize the 401-402 MHz and 2200-2290 MHz band only when in contact with

specified Earth stations and potentially conflicting uses of the band in other regions of the world

are not relevant to this application.

       Spectrum Sharing and Interference Mitigation Techniques

       The S-band communications system employs multiple design considerations that make it

highly unlikely that harmful interference could result to any other satellite network. These include

low-altitude, near-polar orbits and the use of short-duration, narrow bandwidth transmissions.

       Sharing With Low Earth Orbit Satellite Networks: The Tyvak network is highly unlikely

to cause unacceptable interference to other low-altitude satellite networks. First, transmissions

from Tyvak spacecraft will be infrequent and of short duration, triggered only by affirmative

command from the Tyvak MOC. Second, conjunction events in which a Tyvak satellite and

another low-altitude satellite are relatively close to each other will occur very infrequently. When

such rare conjunction events do occur, there will still be no potential for interference unless both

satellite systems are transmitting at the same time, which would only happen when a Tyvak-

affiliated earth station is in close geographic proximity to the earth station of another network.

Given the international allocation for EESS across the entire 2200-2290 MHz band, other NGSO

satellites operating in proximity to any Tyvak satellites are highly likely to follow similar

                                                 11


interference mitigation procedures as those outlined above, resulting in high confidence that Tyvak

operations will not cause unacceptable interference to other low-altitude satellite networks.

       Sharing With Geostationary Satellite Networks: The Tyvak network is highly unlikely to

cause unacceptable interference with geostationary (“GSO”) or other high-altitude satellite

networks. The 2200-2290 MHz band is not significantly used by GSO satellite networks. Further,

the Tyvak network will utilize the 2200-2290 MHz band only in the space-to-Earth direction,

preventing any potential interference toward the geostationary arc. With respect to space-to-Earth

transmissions from GSO spacecraft using the 2200-2290 MHz band, these will be protected from

harmful interference from the Tyvak satellite transmissions in the same manner as Tyvak will

protect space-to-Earth transmissions from low Earth orbit NGSO networks, as discussed above.

       Sharing With Fixed Service Networks: The Tyvak network operates in compliance with the

ITU power limits specified to protect the Fixed Service operating in the 2200-2290 MHz band.

Table 21-4 of ITU Radio Regulation number 21.16 specifies the following PFD limits at the

Earth’s surface for emissions from EESS space stations operating in the 2200-2290 MHz band for

all conditions and for all methods of modulation.

                                             Limit in dB(W/m2) for angles
 Frequency                              of arrival (δ) above the horizontal plane      Reference
                      Service*
   band                                                                                bandwidth
                                         0°-5°             5°-25°           25°-90°
2 200-           Earth exploration-      −154         −154 + 0.5(δ − 5)      −144         4 kHz
2 300 MHz        satellite
                 (space-to-Earth)


       When calculated at the minimum anticipated operating orbital altitude for the Tyvak-0129

of 450 kilometers, the PFD levels at the Earth’s surface produced by the Tyvak satellite data and

telemetry downlink transmissions will comply with these limits.


                                                 12


Section 25.114(c)(5)(i) Orbital Locations

       Tyvak-0129 will be operating in LEO with the orbit parameters shown in Table 6. Each

satellite will have an orbit period of roughly 1.6 hours with typical ground access times of five to

seven minutes per pass. The orbit parameters are presented in the following table:

  Spacecraft                    Parameter                    Units         Value
                                Orbit Period                 hrs           1.6 hrs
  Tyvak-0129                    Orbit Altitude               km            500 km (circular)
                                Inclination                  deg           98 degrees
                               Table 6: CubeSat Orbit Parameters

Section 25.114(c)(10) Physical Characteristics of Satellites

       The Tyvak-0129 space vehicle is a nano-class satellite (< 14 kg), in which each element

conforms to the CubeSat Standard. CubeSats can be designed in different sizes as long as they are

multiples of the basic CubeSat standard unit, which is 10×10×10 centimeters, generally referred

to as a 1U CubeSat, meaning one unit in size. Tyvak-0129 is 6U in size, which means each

CubeSat will have the dimensions of approximately 30×20×10 centimeters or 30 x 20 x 10cm.

The CubeSat dispenser limits the total vehicle mass of a 6U CubeSat to less than 14 kg

respectively. The Tyvak-0129 vehicle has been designed primarily as a single-string system using

commercial off-the-shelf parts with a mission lifetime of approximately two years on-orbit. The

mass budget is identical for each satellite and is provided in the following table:

                        Component / Subsystem                Mass [g] 6U
                        Payload                                3000
                        Spacecraft (Subtotal)                  9200
                          Structure                            2500
                          Electrical Power System              3150
                          ADCS                                 2000
                          C&DH                                  700
                          Communication                         450
                          Harnessing                            300

                                                 13


                         Component / Subsystem                Mass [g] 6U
                           Thermal                               100
                         TOTAL                                  12200
                          Table 8: Spacecraft Mass Budget per Element

       For power generation, Tyvak-0129 is equipped with a single-axis sun-tracking drive

assembly securing two deployable solar array wings that generate approximately 61 watts of power

during a typical orbit. Because of the short operational lifetime of the satellite (i.e., approximately

two years), the difference between the beginning-of-life (“BOL”) and end-of-life (“EOL”) power

generation is negligible. To permit operations during eclipse, energy is stored on-board using Li-

ion batteries, with power being distributed to subsystems and components through the electrical

power subsystem circuitry. The EOL power budget is provided in the following table:

                      Component / Subsystem             EOL Power [mW]
                                                        Orbit Averaged (6U)
                      LM Payload                        20000
                      Accion Payload                    12000
                      Spacecraft (Subtotal)             23000
                        Power Subsystem                 1000
                        ADCS                            7000
                        C&DH                            7000
                        Communication                   7500
                        Thermal/Sensors                 500
                      TOTAL                             55000
                            Table 9: Power Budget per Space Vehicle

Section 25.114(c)(12) Schedule

       The project timeline and major milestones for the launch and operation of the Tyvak-0129

are provided in the following table. The dates are approximate and contingent upon the exact

launch date (“Time of Launch” or “ToL”), orbit parameters, and unforeseen events during on-orbit

operations.

          Milestone                        Date                   Notes


                                                  14


Launch                        February 2019      ToL + 0
Release from launch adapter   February 2019      ToL + 0hr 30min
On-orbit check                February 2019      ToL + 24 hours
Start of experiments          March 2019         ToL + 4 weeks
Decommissioning               February 2021      ToL + 24 months
Re-entry                      February 2022      ToL + 3 years
                  Table 10: Tyvak-0129 Major Milestones




                                   15


Section 25.114(d)(1) General Description of Overall System Facilities, Operations and
                     Services

        The Tyvak-0129 space vehicle provides a platform for flight performance evaluation of the

bus avionics suite and on-orbit technology demonstration of the two experimental payloads: the

low-thrust electric propulsion system from Accion and the RF receiver system from LM. The

onboard systems on each space vehicle provide nominal attitude, electrical power, data storage,

and command function for both mission payloads. The space vehicles communicate with the Earth

stations through a low-rate (19.2 kbps) half-duplex communications link operating in the UHF

band.

        The spacecraft will be supported by a UHF Earth station at the Irvine MOC and several

additional Earth stations operated by Tyvak affiliates at sites in Deadhorse, Alaska; Bardufoss,

Norway; Benevento, Italy; and San Diego, California.     S-band Earth stations will be located in

Svalbard, Norway. The S-band Earth stations will be operated under contract by third-party S-

band network providers.

        The primary responsibilities of the Irvine MOC will be to command the space vehicles to

initiate the experiments, recover spacecraft engineering telemetry, and manage the function of the

spacecraft. The Earth station equipment comprises a UHF yagi antenna array and UHF transceiver.

The MOC will also have vehicle control workstations and a mission data archive server. 2




2
 T&C data will be received directly from the spacecraft via UHF link; payload data will be
downlinked via S-band to third-party Earth stations and securely transmitted to the MOC via a
VPN over the Internet.

                                               16


Section 25.114(d)(3) Predicted Spacecraft Antenna Gain Contours

       The spacecraft UHF antenna is a half wavelength L-dipole antenna, which is essentially

omni-directional when mounted on the corner of a CubeSat structure. A simulation of the antenna

design is shown in Figure 3.




                       Figure 3: Tyvak-0129 L-Dipole UHF Antenna Gain Plot

       The spacecraft S-band antennas are microstrip patch antennas possessing a maximum gain

perpendicular to the surface normal to the patch. A representative antenna gain pattern cut is

provided below for the S-band patch.




                                              17


                             Figure 4: CubeSat S-band Antenna Gain Plot



Section 25.114(d)(14) Orbital Debris Mitigation

       The CubeSat spacecraft will mitigate orbital debris by the following means:

Section 25.114(d)(14)(i) Limiting the amount of debris released during normal operations
                         and the probability of the satellite becoming a source of debris by
                         collisions with small debris or meteoroids that could cause loss of
                         control and prevent post-mission disposal

       In order to limit the amount of debris generated during normal operations, the CubeSats

have been designed so that all parts will remain attached to the satellite during launch, ejection,

and normal operations. This requirement is intrinsic to all satellites conforming to the CubeSat

Standard and compliance is required for launch using the Poly-Picosatellite Orbital Deployer (“P-

POD”) system.

                                                18


       The basic geometry of Tyvak-0129 is a monolithic cubic structure (i.e., 30cm x 20cm x

10cm) with two pairs of 30cm x 70cm triple-deploy panel wings. Based on an orbital debris model

(ref. NASA DAS v2.0.2), the probability of a single particle impact with a size of 1 millimeter or

larger over the mission lifetime is very low (i.e., roughly 1.0 x 10-6). This low probability of impact

for the mission is a result of the small effective area of the space vehicle (i.e., effective area ~

0.221 m2) and the relatively short mission duration (i.e., mission life less than two years).

       Catastrophic system failure due to orbital debris or micrometeoroid impact will not affect

the vehicle’s ability to de-orbit within the guidelines for vehicles operating in LEO (i.e., less than

25 years). Based on the 500km mission orbit, the space vehicle is anticipated to re-enter the

atmosphere within 3 years based on lifetime prediction simulations for the current mission epoch

(i.e., launch in CY2019).

Section 25.114(d)(14)(ii) Limiting the probability of accidental explosions during and after
                          completion of the mission operations

       The vehicles possess energy storage devices (i.e., Li-ion batteries), which will be left in a

nearly discharged state as part of the decommissioning procedure.

Section 25.114(d)(14)(iii) Limiting the probability of the satellite becoming a source of debris
                            by collisions with large debris or other operational space stations

       Based on a simple orbital debris model (ref. NASA DAS v2.0.2), the probability of the

CubeSats colliding with large debris or other space systems of sizes one centimeter or greater at

the mission orbit altitude and inclination is negligible (i.e., roughly 1x10-6).

       The launch provider has instituted deployment procedures in order to place the co-

manifested satellites in the launch vehicle into slightly different orbits in order to reduce the risk

of collision. One of these procedures is to stagger deployment times. In addition, the deployable

solar arrays will be inhibited from deploying for a pre-determined amount of time in order to

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minimize the surface area profile of the vehicle and further reduce chance of collision with another

co-manifested satellite.

Section 25.114(d)(14)(iv) Post-mission disposal plans for the space station at end of life

       The post-mission disposal plan for the spacecraft includes the transition of all vehicle

systems to a dormant state, which includes the cessation of all radio operations (i.e., transmit and

receive). Energy storage devices will be held at a minimal charge state at the end of the life of the

vehicles. Anticipated atmospheric re-entry of the satellites is within 3 years of mission completion

based on the mission orbits, vehicle masses, geometry and mission epochs (i.e., launch in

CY2018). No active de-orbit maneuvers are required to meet the 25-year re-entry guidelines.

       Re-entry debris and probability of human casualty will be negligible. The materials used

on the vehicles include aluminum and PCB material, which have a relatively low melting

temperature as compared to other materials such as Ti or stainless steel, and are not expected to

survive reentry.

III.   CONCLUSION

       The Experimental Licensing Branch should grant Tyvak’s application for a standard two-

year experimental authority to launch and operate the Tyvak-0129 NGSO LEO satellite, which

will permit Tyvak to demonstrate and evaluate operations and systems for government and non-

government customers, adding valuable on-orbit performance data for future CubeSat Standard

satellites. Tyvak’s operation will not cause harmful interference to any licensed service. Tyvak

will operate using the 400.15-402 MHz UHF band and the 2200-2290 MHz portion of the S-band

allocated for EESS operations. Further, the Tyvak operation will meet the Commission’s orbital

debris mitigation requirements. Therefore, Tyvak’s application should be granted at the soonest

practicable time.

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Document Created: 2018-12-11 16:02:08
Document Modified: 2018-12-11 16:02:08

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