The WenTian module is mainly used to support astronauts' stay, exit activities, and carry out space science experiments.
At 06:22:22 UTC on July 24, 2022, the Long March 5B Y-3 carrier rocket carrying the WenTian experimental module was ignited and launched on time at the Wenchang Space Launch Site in Hainan Province, China. After about 495 seconds, the Wentian experimental module and the rocket separated and entered the intended orbit, the launch was a complete success.
This is the 24th flight mission since the establishment of China's manned space project. The Wentian experimental module launched is the second section of the Chinese space station and the first scientific experimental module.
The Wentian experimental cabin is composed of a working cabin, an airlock cabin, and a resource cabin. The take-off weight is about 23 tons. It is mainly used to support astronauts/taikonauts' stay, exit activities, and carry out space science experiments. At the same time, it can be used as a backup for the Tianhe core cabin. Manage the space station.
The future expansion structure of China Space Station, which according to China manned space authorities, shall weigh over 180 tons. Now, with Wentian being docked to the Tianhe, the weight of the space station combination has reached some 50 tons.
The Docking to stations core module "TianHe" is scheduled in 12 hrs.
Liang Xiaofeng, the chief electricity designer of Wentian, told from a technical point of view, Wentian has paved the way for the expansion, but subsequent plans will be in accordance with the overall project. "We will have to analyze and sort out the needs for each plan, but we definitely have acquired the key technologies [for module expansion] in reserve."
New modules to be added to the T-shape strucure could be foreign spacecraft such as lab modules or manned spacecraft, Pang Zhihao, a senior space expert.
Summarizing the functions of the lab module, the state owned space giant China Aerospace Science and Technology Corp (CASC) the major contractor of the space station program, states that Wentian is mainly designed with the ability of unified management and control of the station assembly, as well as the ability to dock, transpose, and park at the core cabin.
It will also support taikonauts' stay in orbit by providing a special airlock cabin and emergency shelter to ensure their safety during extravehicular activities or spacewalk missions, and support various scientific experiments in and outside the cabins.
To start with, with Wentian docked to the space station combination, the living, and working areas for the taikonauts will instantly be doubled. Also, the bigger-diameter airlock of Wentian would facilitate the crew's spacewalking missions, an obvious change for the better to the crew, among others.
The key platform functions of Wentian are the same with those on Tianhe, meaning that the two would serve as each other's backup, and both of them are capable of covering all task requirements needed for the assembly, the CASC said.
Weighing 23 tons at launch, Wentian consists of three parts: a working cabin, an airlock cabin and a resource cabin, with a total length of 17.9 meters, and a diameter of 4.2 meters.
in comparison, the Tianhe core cabin which is 16.6 meters long and weighing 22.5 tons. Wentian is also heavier than any other single-module spacecraft with flight function that remains in active service, including those deployed in the International Space Station, according to the CASC.
The working cabin of Wentian is by far China's largest singular-sealed cabin, including three sleeping areas and one sanitary area. Upon docking, the space station will be able to accommodate six astronauts. That is to say that when the Shenzhou-15 mission crew meets the Shenzhou-14 for rotation in space, Li Jinlin, a chief designer of extravehicular suits at the Astronaut System under China Manned Space Agency.
The airlock cabin has a unique shape – square outside but round inside. It is an "upgraded version" of the one in the core module, expanding the "fitting room" for astronauts to change into space suits and prepare for their spacewalking missions, and a one-meter-diameter gate, enabling a more convenient exit and enter for the astronauts, while also allowing them to carry larger equipment outside the cabin.
Therefore, the airlock cabin of Wentian will become the main exit-entry point for extravehicular activities, while the previous one in Tianhe will serve as backup.
Meanwhile, with two exit-entry cabins, they will greatly boost the reliability and better ensure the safety of taikonauts in case of emergency during extravehicular works, Li said.
Outside the airlock cabin are 22 extravehicular payload interfaces. In the upcoming years, experimental payloads delivered to the space station will be accurately "plugged in" to their corresponding interfaces through the help of robotic arms, no longer needing the manual operation of astronauts- CASC.
Wentian lab module is a five-meter-long small robotic arm installed outside the airlock cabin. With seven degrees of freedom, the set has higher precision and flexibility to "grasp" small and medium-sized equipment and is capable of more delicate operations than the bigger robotic arm with the Tianhe module.
The weight and length of the small robotic arm are about half of the large one on the Tianhe core cabin, and the load capacity is about one-eighth of the large arm. When combined, they will have a total length of 15 meters, and will be able to "climb" over all the three modules of Tianhe, Wentian and Mengtian in the future.
Wentian lab has also host eight experimental cabinets. It will mainly focus on the study of space life sciences, which can support the growth, development, genetics and aging of multiple species of plants, animals and microorganisms under space conditions, - Lv Congmin, a research fellow at the Chinese Academy of Sciences and deputy chief designer of the space utilization system of China Manned Space Program,
More than 10 research directions have been planned and over 40 scientific projects have been established for Wentian, Lv said. Including 31-day scientific space mission TumorsInSpace in 2026, a team led by Norwegian scientist Dr. Tricia L Larose will board the station.
Apart from its extra large size, Wentian has a set of extraordinarily-long wings - flexible solar panels with double degrees of freedom. The full wingspan is over 55 meters, longer than half a soccer field, setting a new record for solar panels used for China's spacecraft. Each panel has an unfolded area of about 110 square meters.
The two solar panels will effectively collect more solar energy, generating an average of more than 430 kiloWatt hours per day and providing sufficient power for space station operations.
By the completion of the space station, one of the solar panels of Tianhe will be transferred to the back of Wentian, and by then the core module will focus solely on the operation of the station, while the lab module will become the main "powerhouse."
The other lab module Mengtian, scheduled to be launched in October 2022, will be oriented to microgravity scientific research and is equipped with experimental cabinets for fluid physics, materials science, combustion science, basic physics and space technology experiments.