China launched its second space station module of the year aboard a Chang Zheng 5B…
China launched its second space station module of the year aboard a Chang Zheng 5B rocket Monday. The Mengtian
module lifted off at 07:37 UTC, and once docked will complete the initial phase of the construction for China’s Tiangong space station.
The launch of the Mengtian
Laboratory Cabin Module, meaning “Dreaming of the Heavens,” follows the successful addition of the Wentian module to China’s Tiangong station on July 24
. Like Wentian
and the Tianhe core module
that was launched in April 2021, Mengtian
will ride into orbit aboard China’s Chang Zheng 5B (CZ-5B) rocket
, also known in English as the Long March 5B.
With a mass of 23,000 kg, a length of 17.9 meters, and a diameter of 4.2 meters, Mengtian
will provide space for science experiments in zero gravity, an airlock for exposure to the vacuum of space, and a small robotic arm to support extravehicular payloads.
is divided into three compartments. The crew working compartment is a pressurized section containing storage racks for science instruments, as well as hosting the docking interface that will connect Mengtian
with the Tianhe
core module. The working compartment contains a wide range of instruments and science spaces, including:
- A fluid physics rack to study the behavior of fluids in zero-gravity
- A two-phase system rack
- A combustion science rack
- A high-temperature materials science rack
- An ultracold atom experiment rack
- A high-precision time-frequency system
- A maintenance and malfunction workstation
The ultracold atom experiment aims to achieve a temperature of 10 picokelvins, which would break the record of the lowest temperature ever achieved by humanity, and surpass a similar experiment that NASA has been conducting in the Cold Atom Lab onboard the International Space Station (ISS)
It is hoped that this experiment will lead to the development of a space-based cold atomic clock, based on hydrogen and rubidium. The goal is to produce the coldest atomic clock ever, which would allow for the most precise time measurement. It would not lose one second of time in hundreds of millions of years, according to Zhang Wei, director of the Space Utilization Development Center.
Once fully assembled, the Tiangong station will feature 23 experiment racks in its pressurized environment. The China Manned Space Agency (CMSA) has already approved over 1,000 experiments that will be conducted on board the space station over the upcoming years.
Together with the direct approach to science, the station is also being used to educate younger Chinese citizens about space. In the past, multiple Q&A sessions have been conducted from orbit, where schoolchildren could ask questions to the station’s crew members. The most recent session was conducted in March 2022.
Outboard of the pressurized crew working compartment is the unpressurized cargo module, which also contains the airlock that the crew will use to release payloads outside of the station. Both the pressurized and unpressurized sections are equipped with reaction control system (RCS) thrusters to help steer the module during free flight, and the station after docking has been achieved.
At the far end of Mengtian
is the control module. This features slots to store external experiments, a communication antenna, and two solar arrays to provide power for the station. The solar panels are initially stowed to fit the module into the fairing of the CZ-5B and will deploy shortly after launch.
Once in orbit, Mengtian
will operate in free flight as it adjusts its orbit to set up a rendezvous with Tiangong. In preparation for its arrival, the Wentian
module was moved to its final position at the starboard port of the station on Sept. 30. This freed up the forward port of Tianhe
, where Mengtian
will dock initially. After a few months on that port, it will be relocated to the port side of the station. This will give Tiangong its final T-shape, concluding its assembly phase.