Mengtian is the second Laboratory Cabin Module (LCM) and third major component of the Chinese spacestation. It will provide a pressurized environment for researchers to conduct science experiments in zero gravity.

The configuration of the CZ-5B variant consists of the Long March 5 core stage with its four strapped-on liquid-fueled boosters, but the usual second stage will be absent; in place of the second stage would be heavier low earth orbit payloads.

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.