The three Shenzhou XXI mission crew members are scheduled to arrive at the Tiangong space station early on Saturday morning, several hours after they embarked on their six-month orbital journey.

Mission commander Senior Colonel Zhang Lu, spaceflight engineer Major Wu Fei and payload specialist Zhang Hongzhang got off the ground at 11:44 pm on Friday as their spaceship's carrier, a 20-story-tall Long March 2F rocket, thundered up into skies from the Jiuquan Satellite Launch Center in northwestern China's Gobi Desert.

Soon after crossing the Karman line, at an altitude of 100 kilometers above sea level, which is the start of outer space and the threshold for orbital flight, the Shenzhou XXI spacecraft separated from the rocket and activated the rapid autonomous rendezvous-docking mode.

According to its docking program, the spacecraft would spend about three-and-a-half hours to approach and connect with the front port of the Tianhe core module, the central piece of the Tiangong.

Following the docking, the Shenzhou XXI crew would use a certain period of time on preparatory work, such as removing their pressure suits and wearing the intravehicular work suits, to make ready for their entry into the space station.

Meanwhile, the outgoing Shenzhou XX team — mission commander Senior Colonel Chen Dong, Colonel Chen Zhongrui and Colonel Wang Jie — would wait inside the connection cabin to welcome their peers.

After all preparations are done, Chen Dong's team would open a hatch in the connection cabin to let the arriving trio float in.

The two teams will stay together for several days for transition work, after which the Shenzhou XX astronauts will depart and return to Earth, according to mission planners.

The Shenzhou XXI crew is conducting China's 16th manned spaceflight and has become the 10th group of residents aboard the Tiangong, which is currently the only operational space station independently run by a single nation.

During their orbital stay, the Shenzhou XXI astronauts will carry out various tasks, including conducting scientific experiments and applications; going on spacewalks to install space debris shield equipment and other instruments; deploying and retrieving devices from outside the space station; and giving science lectures.

Specifically, Zhang Lu and his teammates are set to kick off 27 new scientific and technological projects for in-depth and systematic research across fields such as space life sciences and biotechnology, space medicine, space materials science, microgravity fluid physics and combustion, and new spacecraft technologies.

At a meeting with journalists at the Jiuquan center on Thursday, Zhang Lu said his team had been ready to fulfill their duties abroad the Tiangong and would try their best to make the Shenzhou XXI mission a full success.

Zhang Hongzhang said it is a privilege that he had taken part in designing one of the sci-tech projects they would bring to the space station, adding that he looks forward to conducting the project in orbit.