The Luch Satellite Data Relay Network, also referred to as Altair and Gelios, is a series of geosynchronous Russian relay satellites, used to transmit live TV images, communications and other telemetry from the Soviet/Russian space station Mir, the Russian Orbital Segment of the International Space Station and other orbital spacecraft to the Earth, in a manner similar to that of the upcoming Indian Data Relay Satellite System and US Tracking and Data Relay Satellite System. Wikipedia