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 YF-100 began development in the early 2000's, along with the smaller YF-115 which would power the LM-6 am dLM-7 upper stages
The YF-115 is a high efficiency/high thrust environmental friendly rocket engine. Development began in the early 2000's, along with its bigger sibling TF-100, which would power the Long March-5,6,7