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.
4 X-band synthetic-aperture radar Earth observation satellites for PIESAT (1 main, 3 sub-satellites), operating in tandem using very long baseline interferometry, with resolution at 0.5 - 5 m.