The first spacecraft to visit China's Tiangong space station this year — the Tianzhou 6 robotic cargo ship — is scheduled to launch on Wednesday night, according to the China Manned Space Agency.

With the Tianzhou 6 atop, the Long March 7-Y7 carrier rocket is set to blast off at 9:22 pm at the Wenchang Space Launch Center in the country's southernmost island province of Hainan, the agency said in a brief news release.

The three-story-tall cargo ship will then travel a couple of hours to rendezvous with the Tiangong station and then dock with the massive outpost in a low-Earth orbit.

The Tianzhou 6 will be the ninth vessel to visit the Chinese space station and the first to do so since the station was completed at the end of 2022.

The Long March 7 is a liquid-fueled rocket developed by the China Academy of Launch Vehicle Technology. Its propellants are liquid oxygen and kerosene and are pollution-free, according to the academy.

The Long March 7 has a height of 53.1 meters, a core-stage diameter of 3.35 m and a lift-off weight of 597 tons.

With six 120-ton-thrust engines, the rocket can send 13.5 tons to low-Earth orbit and 5.5 tons to sun-synchronous orbit.

Last week, the Tianzhou 5 cargo craft undocked from the Tiangong station and started a solo flight. Its connection hatch will be used by Tianzhou 6.

Tianzhou 5 is scheduled to re-dock with the space station in the coming weeks after the departure of the Shenzhou XV crew, who will return to Earth after their six-month journey ends.

At present, the Shenzhou XV astronauts — mission commander Major General Fei Junlong, Senior Colonel Deng Qingming and Senior Colonel Zhang Lu — have conducted four spacewalks to mount equipment required for extravehicular scientific experiments and technological demonstrations.