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

The station is constantly crewed by teams of three astronauts, who are rotated out every six months.

The Shenzhou-17 module carrying the trio to the station is scheduled to blast off at 11:14 a.m. (0314 GMT) Thursday from the Jiuquan launch site in China's arid northwest.

"It is the crew of astronauts with the youngest average age since the launch of the space station construction mission," Beijing's State Council Information Office said in a statement.

The all-male trio will be led by Tang Hongbo, who is on his first return mission to the Tiangong space station.

"Throughout the past two years, I have often dreamt of going back to space," Tang said at a press conference on Wednesday.

"The space station is our other home that takes us away from Earth and into the universe," he added.

Accompanying him will be Tang Shengjie and Jiang Xinlin, both in their thirties and each making maiden space voyages.

The crew has an average age of 38, compared to 42 for the crew of Shenzhou-16 when it launched.

"According to the plan, the Shenzhou-17 spacecraft will conduct autonomous rendezvous and docking procedures after entering orbit," Lin Xiqiang, spokesperson for China's space program, said during a Wednesday morning press briefing.

It will dock with the station's core module "about six-and-a-half hours" after first initiating the procedure, he added.

'Space dream'

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 program in an effort to catch up with the United States and Russia.