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.

The Long March 4C, also known as the Chang Zheng 4C, CZ-4C and LM-4C, previously designated Long March 4B-II, is a Chinese orbital carrier rocket. It is launched from the Jiuquan, Taiyuan Satellite Launch Centre and Xichangs, and consists of 3 stages. Long March 4C vehicles have been used to launch the Yaogan-1, Yaogan-3 SAR satellites and the Fengyun-3A polar orbiting meteorological satellite. On December 15, 2009 a Long March 4C was used to launch Yaogan 8.