A Long March 5B carrier rocket carrying the Wentian lab module blasts off from the Wenchang Spacecraft Launch Site in South China’s Hainan province on July 24. (LI GANG / XINHUA)
China launched its Wentian space laboratory on July 24, sending the country’s largest-ever spacecraft into Earth’s orbit to become part of the Tiangong space station.
Encased in a 20.5-meter-long payload, the space lab was carried by a Long March 5B rocket that blasted off at 2:22 pm from a coastal service tower at the Wenchang Space Launch Center in Hainan province.
After a flight of about eight minutes, the rocket placed the craft into a low-Earth orbit nearly 400 kilometers above the ground.
After about 13 hours, Wentian made a rendezvous and docked with the Tiangong station’s Tianhe core module, according to the China Manned Space Agency.
The Shenzhou XIV mission crew now flying with Tiangong — mission commander Senior Colonel Chen Dong, Senior Colonel Liu Yang and Senior Colonel Cai Xuzhe — then entered the lab module to check its condition and internal equipment.
In the coming weeks, Wentian will be repositioned by a robot apparatus from the forward docking port to a lateral port, where it will remain and be prepared for long-term operations, mission planners said.
To prepare for Wentian’s arrival, the Tianzhou 3 cargo spacecraft departed from the Tiangong station on July 17 to leave its docking hatch for the lab.
The cargo ship, which was launched in September and had remained connected to Tiangong since then, will be guided by ground controllers to eventually fall back to Earth.
Before Wentian’s docking, Tiangong consisted of the Tianhe module, the Tianzhou 4 cargo ship and the Shenzhou XIV spacecraft.
Assembled at a manufacturing and testing complex in the northern municipality of Tianjin, Wentian was transported by ship and arrived in Wenchang in late April. It underwent function and prelaunch checks over the past three months at the launch center.
The first lab component of the Tiangong station, Wentian features cutting-edge technologies, strong capabilities, sophisticated design, and represents a new milestone in China’s space industry. It incorporates the wisdom, dedication and hard work of numerous scientists, engineers and technicians, according to the China Academy of Space Technology, which was responsible for designing and making the craft.
The vehicle consists of three major parts — a crew working compartment, an airlock cabin and an unpressurized service module.
Weighing 23 metric tons, the space lab is 17.9 meters tall, roughly equivalent to a six-story residential building, and has a diameter of 4.2 meters. It is the largest and heaviest spacecraft China has ever built and also the world’s heaviest self-propelled spaceship in service, said Zhang Qiao, head designer of Wentian’s overall structure.
The flexible solar panels of the lab are the largest of their kind in China. When fully unfolded, they are more than 55 meters long and have a combined area of nearly 280 square meters.
Wentian’s airlock cabin will replace the one on the Tianhe module to become the main place for astronauts to put on their spacewalk suits and move out of the space station.
“Its inner space is bigger than that of the airlock cabin on the core module while its hatch is wider, making it easier for astronauts to make preparations and carry out spacewalks,” Zhang said.
Shenzhou XIV astronauts Chen Dong (center), Liu Yang (right) and Cai Xuzhe salute from the Wentian lab module on July 25. The Shenzhou XIV astronauts opened the hatch of Wentian, the first lab module of China’s space station, on July 25 at 10:03 am (Beijing time) and entered the module, according to the China Manned Space Agency. (XU BU / FOR CHINA DAILY)
Inside the gigantic lab, there are eight scientific cabinets. They will mainly be used for biological and life science studies and can support research on the growth, aging and genetic traits of plants, animals and microbes in the environment of space, he said.
Outside the airlock cabin, there are 22 extravehicular payload adapters capable of carrying scientific equipment needed for experiments that require exposure to the space environment, cosmic rays, vacuum and solar winds, Zhang added.
“In addition to its scientific functions, Wentian also serves as a backup control station to the Tianhe core module in case of emergencies or malfunctions. It has all the same flight-control devices as those inside the core module to operate the entire Tiangong station,” Zhang said.
The designer added that the craft has three separate sleeping quarters and an independent section for personal hygiene. They can be used in emergencies or handovers by two crews.
Wentian also has a five-meter robotic arm that can be used to move small and medium-sized equipment. It can be linked with the 10-meter robotic arm on the Tianhe module to create a joint arm capable of reaching all major parts of the Tiangong station, according to the designer.
Pang Zhihao, an observer of manned spaceflights, said the Wentian program is one of the most challenging and sophisticated space programs China has embarked on.
“You can imagine just how difficult it must have been to design, manufacture and deploy such a massive, advanced space lab,” he said.
“Both Wentian and Tianhe are big and heavy, while there are astronauts inside the Tianhe. We had no prior experience of connecting two spacecraft of this size.”
Wang Yanan, editor-in-chief of Aerospace Knowledge magazine, called the space lab a “marvel of modern engineering and technology”.
He said that once scientific equipment inside Wentian begins to operate, the equipment will become valuable assets for scientists around the world by making many new science ideas possible and fostering international cooperation.
Mission planners said the Tiangong station’s second lab, Mengtian, will be lifted by a Long March 5B from Wenchang in October.
After it is connected with Tiangong, the station will form a T-shaped structure and astronauts will have as much as 110 cubic meters of usable space.
After the labs, the Tianzhou 5 cargo craft and the Shenzhou XV crew are scheduled to arrive at the massive orbiting outpost around the end of the year.
Upon its completion, Tiangong will be manned regularly by groups of three astronauts in periods usually lasting six months. During handovers to a new three-astronaut group, the station will accommodate up to six astronauts.
In the long run, the orbiting outpost will be capable of docking with multiple crewed and cargo ships at the same time and will also be able to link with foreign spacecraft if they have a Chinese-standard docking hatch.
Currently, Tiangong is manned by the Shenzhou XIV mission crew, who entered the station late on June 5, several hours after their spacecraft was launched from the Jiuquan Satellite Launch Center in northwestern China.
The third group of Tiangong occupants, Chen and his teammates are scheduled to stay in the station for six months to monitor the assembly of the colossal station in space.
The flight of the three astronauts inaugurated a 10-year period in which, barring unforeseen circumstances, Chinese astronauts will be in space every day.
