Response to correspondence reference 26736

0831-EX-PL-2014 Text Documents

BlackSky Global, LLC

2015-02-20ELS_159196

BlackSky Global, LLC
3415 S. 116th Street, Suite 123
Tukwila, WA 98168

February 18, 2015

Subject: Re: file number 0831-EX-PL-2014, correspondence reference number 26736

Dear Ms. Nguyen,

This information is in response the FCC’s February 3, 2015 request for information in regards to the above-referenced
application number. This document contains responses to each of the questions contained in that email. Each question is listed
in this document, with the answer following each question. Please let me know if you have additional questions.

Sincerely,

John Springmann, Ph.D.
Lead Systems Engineer
jspringmann@blacksky.com

Question 1:
“Please submit inclination angle, apogee (km)/perigee (km), orbit period (hours), fractions of hours in decimal and number
of satellites in the system.”

97.4° inclination, 720 km altitude at apogee, 450 km altitude at perigee

Orbital period: 96.74 minutes, which is equivalent to 1.612 hours.

Number of satellites in system: 2

Question 2:
“An analysis transmitting between satellites to satellite.”

There is no satellite-to-satellite communication. Even though two satellites are launching at the same time, there are only
space-to-ground and ground-to-space links.

Question 3:
“An analysis transmitting between satellites to ground stations.”

The table below shows the link budgets for all uplinks and downlinks. A description of each link (one link per table column) is as
follows:

            UHF Uplink (Ground to Space): Ground to space link is near 450 MHz UHF using a RHCP crossed Yagi transmitting at 5
             W RF to a whip antenna on the spacecraft.

            UHF Downlink (Space to Ground): Space to Ground link is in the 401-402 MHz commercial UHF band using a linearly
             polarized whip antenna on the spacecraft transmitting 2 W RF to a RHCP crossed Yagi at the ground station.

            Typical S Band Uplink (Ground to Space): Ground to space link is in the 2025-2110 MHz Space Operations Service band
             using a 3.7 m parabolic dish to transmit 25 W RF to a patch antenna on the spacecraft, both RHCP. Applicable to all
             ground sites except Fairbanks, AK.

            Typical X Band Downlink (Space to Ground): Space to Ground link is in the 8025-8175 MHz Earth Exploration Satellite
             band using a patch antenna on the spacecraft to transmit 8 W RF to a 3.7 m dish at the ground station, both RHCP.
             Applicable to all ground sites except Fairbanks, AK.




                                               BlackSky Global, LLC Proprietary


        Fairbanks S Band Uplink (Ground to Space): Ground to space link is in the 2025-2110 MHz Space Operations Service
         band using a 9.1 m parabolic dish to transmit 15 W RF to a patch antenna on the spacecraft, both RHCP. Applicable to
         the Fairbanks, AK ground site only.

        Fairbanks X Band Downlink (Space to Ground): Space to Ground link is in the 8025-8175 MHz Earth Exploration
         Satellite band using a patch antenna on the spacecraft to transmit 8 W RF to a 9.1 m dish at the ground station, both
         RHCP. Applicable to the Fairbanks, AK ground site only.


Note that this link budget assumes 720 km mean orbit altitude and a 10 degree elevation above the horizon.




                                           (Intentionally left blank – see next page)




                                           BlackSky Global, LLC Proprietary


                                                               UHF             Typical S Band        Typical X Band        ASF S Band
                                            UHF Uplink       Downlink              Uplink              Downlink              Uplink           ASF X Band Downlink
From:                                       Ground          Space            Ground                  Space              Ground                Space
To:                                         Space           Ground           Space                   Ground             Space                 Ground
Transmit Power (Watts):                                5                2                       25                 8                    15                      8
Frequency, MHz:                                      450             401.5            2071.875                  8080             2071.875                   8080
Transmit Antenna Gain, dBi:                           16                3                  33.5                   15                 43.6                     15
Losses to Antenna, dB:                               2.85             0.73                 1.99                  0.95                0.56                    0.95
Transmitter EIRP, dBm:                              50.14            35.28                75.49                 53.08               84.80                   53.08
Slant Range, km:                                    2198             2198                  2198                 2198                2198                    2198
Path Loss, dB:                                      152.4            151.4                162.7                 174.5               162.7                   174.5
Polarization Loss, dB:                                 3                3                  0.67                  0.23                0.67                    0.23
Transmit antenna pointing loss, dB:                   0.1              1.5                      0                 0.3                    0                    0.3
Receive antenna pointing loss, dB:                    1.5               0                       3                 0.1                    3                    0.1
Isotropic signal at Receive antenna, dBm:      -106.86          -120.62                  -90.88               -122.05              -81.57                 -122.05
Receive Antenna Gain, dBi:                             3              18.5                      6                45.9                    6                    56
Losses to Receiver, dB:                              1.72               1                  1.72                  1.11                1.72                    1.11
Received Power at LNA input, dBm:              -105.58          -103.12                  -86.60                -77.26              -77.29                  -67.16
Receive Noise Figure, dB:                             3.5             0.75                  3.5                  0.69                   3.5                  0.69
Sky Temperature, K:                                  230              121                   290                   69                 290                      69
System Noise temperature:                            548              294                   602                  182                 602                     182
Receiver G/T, dB/K:                             -26.11               -7.18               -23.52                 22.19              -23.52                   32.29
Data Rate, bps:                                     9,600       440000                  100,000              1.00E+08             100,000               1.00E+08
Receiver Bandwidth, Hz:                         40,000          845000                  188000               1.51E+08             188000                1.51E+08
Noise Power, dBm:                              -125.19          -114.65                 -118.06                -94.21             -118.06                  -94.21
CNR, dB/Hz:                                         19.61            11.53                31.46                 16.95               40.77                   27.05
Required S/N, dB:                                    14.8             10.6                 10.6                  10.6                10.6                    10.6
Coding Gain, dB :                                    5.44               5                       2                5.44                    2                   5.44
System Link Margin, dB:                             10.25             5.93                22.86                 11.79               32.17                   21.89



                                                              BlackSky Global, LLC Proprietary


Question 4:
“Location of ground stations including latitude and longitude.”

    Location               Bands in Use         Address                        Latitude/Longitude        Elevation
                                                                                                         AMSL (m)
    Tukwila, WA            UHF only             3415 S 116th St #123,          47° 29' 55.44" N,         15.9
                                                Tukwila, WA                    122° 17' 23.64" W
    Redmond, WA            S/X only             6742 185th Ave, NE             47° 40' 00.88" N,         33
                                                Redmond, WA 98052              122° 05' 34.02" W
    Fairbanks, AK          UHF, S, X            903 N Koyukuk Dr               64° 47' 37.0" N,          144
                                                Fairbanks, AK 99775            147° 32' 10.8" W
    Prudhoe Bay, AK        UHF, S, X            Track 11, North Slope Lease    70° 13' 28.42" N,         9.1
                                                Tracts, Umiat Meridian, AK     148° 25' 38.02" W
    Spaceport America,     UHF, S, X            234 Aleman Rd                  32° 59' 46.8" N,          1415
    New Mexico                                  Truth or Consequences,         106° 59' 3.9" W
                                                NM 87901


Question 5:
“Information of satellite transmitter antenna including gain, beamwidth, azimuthal range.”

    Antenna                    Gain                          Beamwidth                    Azimuthal Range1
    UHF whip (Tx & Rx)         3 dBi                         180° (nearly-omni)           Body-fixed*
    S-band patch (Rx)                       -                n/a – receive only                      -
    X-band patch (Tx)          15 dBi                        18°                          Body-fixed*


Question 6:
“Information of earth station receiver antenna including gain, beamwidth, azimuthal range, elevation
above mean sea level (m), minimum angle of elevation and antenna height above terrain (m).”

    Location              Beamwidth Azimuthal Range               Elevation         Min Elevation         Height above
                                                                  AMSL (m)          angle2 (deg)          terrain3 (m)
    Tukwila, WA        UHF: 30°           UHF: 0-360°             15.9              0°                    UHF: 10
    Redmond, WA        S/X: 1°            S/X: 0-360°             33                0°                    S/X: 15.2
    Fairbanks, AK      UHF: 30°           UHF: 0-360°             144               0°                    UHF: 5
                       S/X: 1°            S/X: 0-360°                                                     S/X: 4
    Prudhoe Bay, AK    UHF: 30°           UHF: 0-360°             9.1               0°                    UHF: 2
                       S/X: 1°            S/X: 0-360°                                                     S/X: 2
    Spaceport America, UHF: 30°           UHF: 0-360°             1415              0°                    UHF: 5
    New Mexico         S/X: 1°            S/X: 0-360°                                                     S/X: 2




1
  Body-fixed means that the antenna is not steerable; it is rigidly attached to the body of the spacecraft. The entire
spacecraft will slew such that the antennas are pointing at the ground station during a contact pass.
2
  0° minimum elevation is desired. We can limit the minimum elevation for transmission, if necessary.
3
  Some locations are approximate – final designs in progress.


                                         BlackSky Global, LLC Proprietary


Question 7:
“Stop Buzzer information including name and telephone number of person who will terminate the
system if having interference occurs”

24/7 POC for ground station operations is Dr. John Springmann, 206-351-5165




                                  BlackSky Global, LLC Proprietary



Document Created: 2015-02-19 16:17:51
Document Modified: 2015-02-19 16:17:51

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