In historic moment, two Shenzhou crews meet in Tiangong space station

The six Chinese astronauts from the Shenzhou XIV and Shenzhou XV missions marked a historic moment on Wednesday as they met inside the country's Tiangong space station.

It was the first time that six Chinese were in a space station at the same time and the first in-orbit gathering of two Chinese crews.

After about two hours of preparatory work following the docking of the Shenzhou XV spacecraft with the Tiangong station in a low-Earth orbit about 400 kilometers above Earth, Major General Fei Junlong, the Shenzhou XV mission commander, opened a hatch on his spaceship and floated into the station's connection cabin at 7:34 am.

He was welcomed by Senior Colonel Chen Dong, leader of the Shen­zhou XIV crew, who had been waiting inside the cabin. "Welcome! Let's hug," Chen said and then embraced him.

Chen then told Fei, "There are two more waiting for you", referring to Senior Colonel Liu Yang and Senior Colonel Cai Xuzhe, who were waiting inside the station's Wentian lab module.

In the following minutes, Senior Colonel Deng Qingming and Senior Colonel Zhang Lu moved into the connection cabin one by one and were greeted by Chen.

The Shenzhou XV trio then entered the Wentian lab module and hugged Liu and Cai, who were waiting there.

The entire process was broadcast live on China Central Television.

The Shenzhou XV crew set out on the journey to the Tiangong station on Tuesday night from the Jiuquan Satellite Launch Center in northwestern China's Gobi Desert. They rode aboard a spacecraft that was lifted into space by a Long March 2F rocket.

According to the China Manned Space Agency, the two crews are scheduled to stay together for about five days, and then the Shenzhou XIV trio, who have been in orbit for nearly half a year, will return to a landing site in the Inner Mongolia autonomous region.

The Shenzhou XV astronauts are tasked with staying in orbit for six months to carry out a number of assignments, such as conducting spacewalks to mount equipment outside the station, installing and testing scientific cabinets, and conducting scientific experiments and technological demonstrations, mission officials have said.

Following the arrival of the Shenzhou XV spaceship, the Tiangong space station has grown considerably. As one of the largest ever space-based assets, the station now consists of the Tianhe core module, the Wentian and Mengtian lab modules, the Shenzhou XIV and Shen­zhou XV spacecraft and the Tianzhou 5 cargo ship.

Tiangong, whose overall weight is nearly 100 metric tons, is expected to operate in orbit for about 10 years and will be open to foreign astronauts in the near future, according to space officials.

It is the 10th crewed space station in world spaceflight history and one of two currently operating stations, along with the International Space Station.

Pang Zhihao, a retired researcher at the China Academy of Space Technology and a renowned writer on space science, said that building and running a manned space station is one of the most sophisticated and difficult scientific, technological and engineering endeavors.

"The construction of the Tiangong space station as well as other remarkable accomplishments like the Tianwen 1 Mars landing show that China has become one of the lead runners in the global space arena," he said. "The arrival of the Shenzhou XV crew marked the start of the Tiangong space station's long-term regular operation."

Yang Yuguang, a senior space industry observer in Beijing and vice-chair of the International Astronautical Federation's space transportation committee, said that nine joint science projects from 17 other nations have been selected to be carried out aboard Tiangong, and the first ones are expected to be sent to the space station in 2023 to be conducted by the crew of the Shen­zhou XV or XVI mission.