The Long March 5B carrier rocket for the launch mission of Mengtian, the second lab module of China's space station, is getting ready at Wenchang Spacecraft Launch Site in south China's Hainan Province.

Before its transportation to the launch pad, CGTN's Zheng Yibing had an exclusive visit to its assembly building, the biggest in Asia with a gate of over 80 meters.

The assembly building was specially designed for China's largest carrier rocket Long March 5-B by far, which is over 50 meters long or tall and has a core-stage diameter of five meters.

On top of the carrier rocket is the payload of the Mengtian lab module for China's space station.

It's the second lab module and will be sent and docked with the station, and together, they will eventually form a T-shape in low-earth orbit.

The previous lab is mainly for life science. This one is designed for physics research, and eight experimental boxes are installed for Shenzhou-14 members to conduct experiments in space.

Now, the rocket is ready for the mission to send the Mengtian lab module into space.

"The Long March 5B carrier rocket and the Mengtian lab module have finished various tests, and both are in good condition and ready to be transported to the launched site," said Zhu Xiaole, an engineer from the department of overall planning at the launch site.

"We are devoted to this mission. This is in line with the spirit of all those working in the aerospace system who work especially hard for the great goal of space exploration for all. And we are fulfilling our commitment," he said.

This mission marks another big step in completing China's space station. Now, the flight combination is ready.