When the US had astronauts aboard Mir, the Russian ground station network was extended by the addition of three US sites: * Wallops Island, Virginia; * Vandenberg AFB, later relocated to Dryden Flight Research Center (Edwards AFB), California; * White Sands, New Mexico. The ISS is using these ground stations on the same Mir air-to-ground frequency. ISS (International Space Station) 2 GHz Spectrum Requirements Note: 4 indicates US spectrum authorization è indicates potential system TransmitFrequency (MHz) Subsystem Description 2287.5 Early Comm ISS-to-TDRS 2265 Assembly Contingency ISS-to-TDRS Subsystem 2400 Wireless Payload Data Internal to ISS Communication Link 2200-2208 FGB Komparus Command FGB-to-Russian System Ground Stations 2860 FGB Tracking System FGB-to-Russian Ground Stations 2860 SM Tracking SM-to-Russian Ground Stations 2030.4375 SM Visiting Vehicle System SM-to-Visiting Vehicle 2200.157-2291.4283 Klyon SM-to-Ground or Data Relay Satellite 2200-2290 JEM Comm JEM-to-Data Relay Receive Frequency (MHz) Receiver Type Description 2106.4 Early Comm TDRS-to-ISS 2085.6875 Assembly Contingency Subsystem TDRS-to-ISS 2400 Wireless Payload Data Communication Link Internal to ISS 2725 FGB Tracking System Russian Ground Stations-to-FGB 2725 SM Tracking Russian Ground Stations-to-SM 2205 SM Visiting Vehicle System Visiting >>Vehicle-to-SM 2025.779-2109.984 Klyon Ground or Data Relay Satellite-to-SM 2025-2110 JEM Comm Data Relay Satellite-to-JEM