REDACTED FOR PUBLIC INSPECTION ATHENA NGSO SATELLITE EXHIBIT 1 Technical Information to Supplement Form 442 and Application Narrative A.1 Scope and Purpose This exhibit supplements FCC Form 442 and contains the technical information referenced in the application narrative that is required by Parts 5 and 25 of the Commission’s rules. A.2 Radio Frequency Plan (§25.114(c)(4)) The Athena satellite will have two E-band uplinks and two E-band downlinks. The downlink emissions are nominally centered at 72 GHz and 75 GHz and the uplink emissions are nominally centered at 82 GHz and 85 GHz1. The bandwidth for both the uplinks and downlinks is 2.1852 GHz. The TT&C uplink will be conducted at 2082 MHz with an occupied bandwidth of 1.5 MHz. The TT&C downlink will be conducted at 8496.25 MHz with an occupied bandwidth of 2.3 MHz. Table A.2-1 shows the frequency ranges to be used by the Athena satellite. 1 There is the possibility that mild tuning may be performed from the planned 72, 75, 82 and 85 GHz centered carriers (e.g., 74.8 and 82.2 GHz may be used for example to mitigate any potential, mild “inter-channel interference” due to spectral regrowth issues and limited transmit- to-receive isolation). In addition, a limited number of tests, estimated at one to two dozen, may be performed with continuous wave (CW), unmodulated carriers as far out as the band edges (i.e., 71-76 GHz and 81-82 GHz) to measure the atmospheric attenuation characteristics. Any mild tuning or atmospheric measurement testing would maintain compliance with NTIA Redbook requirements for the licensed carriers. 1 REDACTED FOR PUBLIC INSPECTION Table A.2-1: Frequency Bands Used by the Athena non-GSO Satellite Type of Link and Transmission Direction Frequency Ranges 80.9074 – 83.0926 GHz E-band Uplink 83.9074 – 86.0926 GHz 70.9074 – 73.0926 GHz E-band Downlink 73.9074 – 76.0926 GHz TT&C Uplink 2081.25 – 2082.75 MHz TT&C Downlink 8494.75 – 8497.75 MHz The E-band uplink and E-band downlink will use both right-hand circular polarization and left- hand circular polarization. The TT&C uplink and TT&C downlink will use right-hand circular polarization. A.3 Non-GSO Orbital Characteristics (§25.114(c)(6)) The Athena experiment will consist of one non-GSO satellite operating in a circular sun- synchronous orbit at an altitude of 500 to 550 km. Table A.3-1 gives the other relevant orbital parameters for the Athena satellite. 2 REDACTED FOR PUBLIC INSPECTION Table A.3-1: Athena Satellite Characteristics Number of Orbital Planes 1 Satellites Per Orbital Plane 1 97.4° for 500 km case Inclination of the Orbital Plane 97.6° for 550 km case 5677 seconds (1 hour, 34.6 minutes) for 500 km case Orbital Period 5730 seconds (1 hour, 35.5 minutes) for 550 km case Apogee 500 – 550 km Perigee 500 – 550 km When visible to the earth stations at Active Service Arc minimum elevation angles of 5° - 30° (See Section A.4 for further explanation) Local Time of Descending Node 10:30 AM It is noted that additional orbital parameters, such as the argument of perigee and the initial phase angle of the satellite, are not applicable to a one-satellite non-GSO system in a circular orbit. The right ascension of the ascending node (RAAN) is dependent upon the specific launch date. The RAAN will change by 0.9856° per day in order to keep up with the 360° Earth rotation around the sun in 365.25 days. A.4 Frequency Bands and Coverage Areas (§25.114(c)(7)) As stated in Section A.2, the E-band downlinks will be in the 70.9074-76.0926 GHz frequency ranges and the E-band uplinks will be in the 80.9074-86.0926 GHz frequency ranges. During nominal operations, the satellite will only transmit and receive in the E-band when it is at an elevation angle greater than or equal to 30° from one of the earth stations located in the Los Angeles/Ventura county area. However, there may be some experiments in which the satellite will transmit and receive in the E-band when it is at a minimum elevation angle of 10°. TT&C will be performed in the 2081.25-2082.75 MHz frequency band for the uplink and the 8494.75-8497.75 MHz band for the downlink. For TT&C, the satellite will only transmit and receive when it is at an elevation angle greater than or equal to 5° from the Mojave, Brewster and 3 REDACTED FOR PUBLIC INSPECTION Albuquerque earth stations. Figures A.4-1 and A.4-2 show the coverage areas for the TT&C links based on these minimum elevation angles. The spacecraft will only transmit and receive when it is within the yellow circles on the figures. The grid shows 15° lines for both latitude and longitude. Figure A.4-1: Global View of Athena Satellite TT&C Coverage Area 4 REDACTED FOR PUBLIC INSPECTION Figure A.4-2: Zoom View of Athena Satellite TT&C Coverage Area Figure A.4-3 and Figure A.4-4 show the coverage areas of the Athena satellite E-band for minimum elevation angles of 30° and 10°, respectively. The spacecraft will only transmit and receive when it is within the green circles on the figures. The grid shows 15° lines for both latitude and longitude. 5 REDACTED FOR PUBLIC INSPECTION Figure A.4-3: View of Athena Satellite E-Band Coverage Area for 30° Minimum Elevation Angle Figure A.4-4: View of Athena Satellite E-Band Coverage Area for 10° Minimum Elevation Angle 6 REDACTED FOR PUBLIC INSPECTION A.5 Calculated Maximum Power Flux Density Levels (§25.114(c)(8)) The Athena satellite’s TT&C downlink operations in part of the 8025-8500 MHz band comply with the ITU Power Flux Density (“PFD”) limits applicable to that band. Table A.5-1 shows the ITU PFD limits in the band. Table A.5-1: ITU Power Flux Density Limits in the 8025 – 8500 MHz Band 2 PFD Limit in dB(W/m ) for angles Reference Frequency range of arrival (δ) above the horizontal plane bandwidth 0°-5° 5°-25° 25°-90° 8025 – 8500 MHz -150 −150 + 0.5(δ − 5) −140 4 kHz The Athena satellite TT&C downlink has a maximum transmit EIRP of 3.64 dBW and a bandwidth of 2.3 MHz. Table A.5-2 shows the maximum PFD at the surface of the earth produced by this emission assuming an orbital altitude of 500 km, which would result in the highest PFD levels. Table A.5-2: Maximum Athena PFD in the 8025 – 8500 MHz Band Maximum EIRP (dBW) 3.64 Bandwidth (MHz) 2.3 EIRP Density (dBW/4 kHz) -23.94 Minimum Distance (km) 500 Maximum PFD (dBW/m2/4 kHz) -148.96 Table A.5-3 shows the calculated maximum PFD levels at the surface of the Earth for elevation angles from 5° to 90° along with the margin and demonstrates that the ITU PFD Limit in the 8025- 8500 MHz band is met. Figure A.5-1 shows the graphical comparison of the Athena maximum PFD levels to the ITU PFD limits. 7 REDACTED FOR PUBLIC INSPECTION Table A.5-3: X-Band TT&C Downlink Compliance with ITU PFD Limits in the 8025-8500 MHz Band PFD with Peak Antenna Gain Margin to Elevation ITU PFD Limit (dBW/m2 / ITU PFD Angle (°) (dBW/m2 / 4kHz) 4kHz) Limit (dB) 5 -150.00 -160.78 10.78 10 -147.50 -159.31 11.81 15 -145.00 -157.70 12.70 20 -142.50 -156.26 13.76 25 -140.00 -155.00 15.00 30 -140.00 -153.91 13.91 35 -140.00 -152.95 12.95 40 -140.00 -152.13 12.13 45 -140.00 -151.65 11.65 50 -140.00 -151.04 11.04 55 -140.00 -150.52 10.52 60 -140.00 -150.09 10.09 65 -140.00 -149.73 9.73 70 -140.00 -149.44 9.44 75 -140.00 -149.22 9.22 80 -140.00 -149.06 9.06 85 -140.00 -148.97 8.97 90 -140.00 -148.96 8.96 8 REDACTED FOR PUBLIC INSPECTION Figure A.5-1: PFD Levels from the Athena TT&C Downlink compared with ITU Limits -135 -140 -145 -150 PFD (dBW/m2/4 PFD (dBW/m2/4 kHz) ITU PFD Limits -155 Calculated Athena PFD -160 -165 0 102030405060708090 Elevation Angle (degrees) There are no ITU or FCC PFD limits in the 71-76 GHz band. In this band, the Athena satellite has a maximum transmitted EIRP of 44.3 dBW and a bandwidth of 2.1852 GHz. Table A.5-4 shows the maximum PFD at the surface of the earth produced by this emission. Table A.5-5 shows the calculated maximum PFD levels for elevation angles from 10° to 90°. 9 REDACTED FOR PUBLIC INSPECTION Table A.5-4: Maximum Athena Satellite PFD at the Surface of the Earth in the 71 - 76 GHz Band Maximum EIRP (dBW) 44.3 Bandwidth (GHz) 2.1852 EIRP Density (dBW/4 kHz) -113.07 Minimum Distance (km) 500 Maximum PFD (dBW/m2/4 kHz) -138.05 Table A.5-5: Maximum Athena PFD in the 71 - 76 GHz Band at Various Elevation Angles Elevation PFD with Peak Antenna Gain Angle (°) (dBW/m2/4 kHz) 10 -148.65 15 -147.04 20 -145.60 25 -144.34 30 -143.24 35 -142.29 40 -141.47 45 -140.76 50 -140.15 55 -139.63 60 -139.19 65 -138.83 70 -138.54 75 -138.32 80 -138.17 85 -138.08 90 -138.05 5.a X-Band TT&C Compliance with Deep Space Protection Limits According to the ITU Radio Regulations, the 8400-8450 MHz band is allocated to the Space Research Service in the space-to-Earth direction and the use of the band is limited to satellites that are orbiting in deep space.