The Shenzhou-18 mission -- crewed by three astronauts -- is scheduled to take off at 8:59 pm Thursday (1259 GMT) from the Jiuquan Satellite Launch Center in northwest China, Beijing said.

It will be led by Ye Guangfu, a fighter pilot and astronaut who was previously part of the Shenzhou-13 crew in 2021.

The latest batch of Tiangong astronauts will stay in orbit for six months, carrying out experiments in gravity and physics, as well as in life sciences.

"All pre-launch preparations are on schedule," Deputy Director General of the CMSA Lin Xiqiang told a press conference.

The Tiangong is the crown jewel of Beijing's space programme -- which has also landed robotic rovers on Mars and the Moon -- and made China the third country to put humans in orbit.

It is constantly crewed by rotating teams of three astronauts.

The new crew will replace the Shenzhou-17 team, who were sent to the station in October.

Plans for China's "space dream" have been put into overdrive under President Xi Jinping.

The world's second-largest economy has pumped billions of dollars into its military-run space programme in an effort to catch up with the United States and Russia.

Beijing also aims to send a crewed mission to the Moon by 2030, and plans to build a base on the lunar surface.