Completion of the assembly of the Chinese orbital station

On October 31, the Long March 5B rocket was launched from the Chinese Wenchang Cosmodrome. The laboratory module “Mengtian” was on board. Just 13 hours after launch, it successfully docked with the Tiangong orbital station. Thus, China has completed the assembly of its space outpost.

Purpose of the Mengtian module

The laboratory module “Mengtian” has a length of 17.9 meters, a diameter of 4.2 meters and an internal space volume of 110 m3. Its mass is 22 tons. The module is designed to conduct a wide range of scientific experiments from research in the field of fundamental physics to experiments to study the behavior of liquid and fire in zero gravity. Mengtian is equipped with its own airlock and a manipulator for its automatic docking between the docking nodes of the station. The module also has an auxiliary 5-meter robotic arm.

Tiangong orbital station in the artist’s image. Source: CNSA

Mengtian became the third element of the Tiangong orbital station after the base module and the Wentian laboratory module. Now its mass is over 65 tons. The station is designed for the permanent stay of three teikonauts and can provide the presence of six people during the “shift change” of the crews.

The successful docking of Mengtian marked the completion of the construction of the basic configuration of the Tiangong station. The Chinese National Space Administration admits that new scientific modules may be added to it in the future. It is also worth noting that at the end of next year, China plans to launch the Xuntian space telescope. Although it is not part of Tiangong, the orbital observatory will dock with the station from time to time for maintenance.

Fate of the first stage of Long March 5B

As in the case of previous Tiangong assembly missions, after the launch of the Mengtian, the spent first stage of the Long March 5B rocket remained in orbit. Its mass is about 21 tons, which is comparable to the mass of the Soviet Salyut-7 orbital station. The stage is in low Earth orbit and will enter the atmosphere in the coming days. 

Launch of the Long March 5B rocket. Source:

Where and when exactly this event will take place is still unknown. For sure, we can only say that the fragments of the stage will fall somewhere between 41° north latitude and 41° south latitude. Thus, it can be compared with a kind of “Russian roulette”. NASA and the governments of several countries have repeatedly criticized the Chinese authorities for the lack of efforts to actively de-orbit and flood the stages of their rockets in safe areas. However, they have not yet demonstrated a willingness to meet halfway on this issue.

According to

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