The Mengtian laboratory cabin module is a major module of the Tiangong space station. It will be the second Laboratory Cabin Module launched, and the second module to extend the existing Tianhe core module of the station.

The Mengtian laboratory module will provide a pressurized environment for researchers to conduct science experiments in freefall or zero gravity which could not be conducted on Earth for more than a few minutes. Experiments can also be placed on the outside of the modules, for exposure to the space environment, cosmic rays, vacuum, and solar winds. It will have its own airlock.

The axial port of Mengtian will be fitted with rendezvous equipment and will first dock to the axial port of Tianhe. A mechanical arm dubbed, as Indexing robotic arm, looking a sort of Lyappa arm used on the Mir space station then moves Mengtian module to a portside port of the TCM.[4][5][6] It is different from Lyappa as it works on a different mechanism. Lyappa arm is needed to control the pitch of the spacecraft and redocking in a different plane. But the indexing robot arm is used when docking is needed in the same plane. In addition to this arm used for docking relocation, the Chinarm on Tianhe module can also be used as a backup in place of Indexing robot arm.

In addition to this, it will also carry a small 5 m (16 ft) long robotic arm like the Chinarm as a supplemental to that arm. It will be used for manipulating extravehicular payloads and its positioning accuracy is 5 times better than the Chinarm. Mengtian has standard adaptors (silver squares) to host the payloads.[9] There is also an adapter by which this arm can be grappled by the Chinarm it to work a single robotic arm like Orbiter Servicing Arm on Canadarms.[10]

Electrical power is provided by two steerable solar power arrays, which use photovoltaic cells to convert sunlight into electricity. Energy is stored to power the station when it passes into the Earth's shadow. Resupply ships will replenish fuel for LCM 2 for station-keeping, to counter the effects of atmospheric drag.

The Long March 5 (LM-5) launch vehicle is a heavy-lift, cryogenic liquid rocket developed by the China Aerospace Science and Technology Corporation (CASC). Designed with principles of generalization, serialization, and modularization, the LM-5 family uses non-toxic, environmentally friendly propellants such as liquid hydrogen, liquid oxygen, and kerosene. Its modular architecture reduces launch costs, improves reliability, and offers strong adaptability and competitiveness in the global space launch market.

Specs

Height: 53.7 meters (176 feet)

Core Diameter: 5 meters (16.4 feet)

Booster Diameter: 3.35 meters (11 feet) each (four boosters)

Liftoff Mass: Approximately 849 metric tons

Payload Capacity to LEO: Up to 25 metric tons

Propellants
Core Stage: Liquid hydrogen (LH₂) and liquid oxygen (LOX)
Boosters: Kerosene (RP-1) and liquid oxygen (LOX)

The Long March 5B (LM-5B) is a variant optimized specifically for delivering heavy payloads to low Earth orbit (LEO). Unlike the standard Long March 5, the 5B version does not include a second stage, making it ideal for missions such as launching space station modules and large satellites into LEO.

The Long March 5 series offers payload capabilities of up to 25 tons to LEO (for the 5B variant) and up to 14 tons to geostationary transfer orbit (GTO) with the standard Long March 5 configuration. It is capable of launching a wide variety of spacecraft, including LEO, GTO, and sun-synchronous orbit (SSO) satellites, as well as modules for space stations and lunar exploration probes.

The Wenchang Space Launch Site located in Wenchang, Hainan, China, is a rocket launch site, one of the two spacecraft launch sites of Xichang Satellite Launch Center.

It is a former suborbital test center. It is China's fourth and southernmost space vehicle launch facility (spaceport). It has been specially selected for its low latitude, which is only 19° north of the equator, which will allow for an increase in payload necessary for launching China's future space station. It is capable of launching the Long March 5, currently the most powerful Chinese rocket.