The BD 1 (Beidou 1) satellites were the 1st phase of the chinese Beidou (Compass) satellite navigation system. The first phase uses only geostationary satellites, in contrast to GPS and GLONASS. This reduces the number of satellites, but limits the coverage to a less than hemispherical area. The basic constellation requires 3 satellites. The satellites are based on the DFH-3 Bus.
The China Aerospace Science and Technology Corporation (CASC) is the main contractor for the Chinese space program. It is state-owned and has a number of subordinate entities which design, develop and manufacture a range of spacecraft, launch vehicles, strategic and tactical missile systems, and ground equipment. It was officially established in July 1999 as part of a Chinese government reform drive, having previously been one part of the former China Aerospace Corporation. Various incarnations of the program date back to 1956.INFO WIKI