Distribution of TT&C stations in space

According to its distribution, there are four types of monitoring stations: land monitoring stations, maritime survey ships, aerial survey aircraft and tracking and data relay satellites. China started to build its own TT&C network from 1967, and officially put it into use from 1970. Initially, the space TT&C communication network consisted of TT&C center of Xi satellite, several space TT&C stations, ocean survey ship and special communication network connecting them. At that time, there were TT&C stations in Changchun, Minxi, Xiamen, Weinan, Nanning and Kashgar. The mobile station has two mobile measurement and control stations and a recovery measurement station; There are three "Roy" survey ships at sea. At the initial stage of network construction, the main measuring equipment included monopulse precision tracking radar, Doppler velocimeter, optical measuring equipment and short-wave telemetry equipment. In the early 1970s, China's first artificial earth satellite, Dongfanghong 1, was successfully put into orbit. Later, dual-frequency Doppler velocimeter, ultrashort wave telemetry system, remote control system and recovery measurement system were added, which can simultaneously measure and control three satellites launched by a launch vehicle. In the early 1980s, a unified microwave TT&C system was added to TT&C network, and advanced TT&C application software was designed for geosynchronous satellites. In all previous launches of geosynchronous communication satellites, TT&C network participated in TT&C flight of active segment, completed TT&C of transition orbit segment and geosynchronous orbit, and carried out long-term TT&C management of satellites, including orbit maintenance. In 1988 and 1990, TT&C network successfully completed the TT&C mission of Fengyun-1, the first and second sun-synchronous orbit meteorological satellite launched by China. Since China launched the American-made "Asia"-1 communication satellite in 1990, China Aerospace TT&C Network began to provide TT&C support for China's international commercial launch mission. China Aerospace TT&C network is more and more technically compatible with major international TT&C networks and can be networked with them.