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
© 2025 FCC.report
This site is not affiliated with or endorsed by the FCC