China successfully launched its space station lab module Wentian, the largest spacecraft ever developed by the country, into orbit on Sunday afternoon.

The Long March-5B Y3 rocket, carrying Wentian (which means "quest for the heavens"), blasted off at 2:22 p.m. Beijing Time from the Wenchang Spacecraft Launch Site in south China's Hainan Province.

Click here for CGTN's live coverage of the event.

About eight minutes later, the lab module separated from the carrier rocket and entered its preset orbit. The China Manned Space Agency (CMS) declared the launch mission a complete success.

On July 17, the Tianzhou-3 cargo craft undocked from Tianhe, leaving its front docking port for the upcoming Wentian lab module.

The Shenzhou-14 crew watched the launch of the Wentian in orbit.

About the Wentian lab module

With a length of 17.9 meters, a maximum diameter of 4.2 meters and a takeoff weight of 23 tonnes, the Wentian module is the largest and heaviest spacecraft China has developed.

It has the same astronaut living facilities as the Tianhe core module, including three sleeping areas, a toilet and a kitchen.

The lab module will provide a bigger platform for scientific experiments in space. It is mainly for space life science research. The module is equipped with laboratory cabinets for life ecology, biotechnology and variable gravity science.

A small robotic arm half the weight and length of the existing robotic arm on the space station's core module is aboard the Wentian module. The robotic arm has a load capacity of about one-eighth of its predecessor, and its end positional accuracy is five times higher than its predecessor, allowing it to conduct more elaborate operations.

The small robotic arm will have similar missions to its predecessor, including assisting astronauts during extravehicular activities and carrying out inspections of extravehicular conditions.

Read more: Wentian, the largest and heaviest spacecraft China ever launched

What's next?

The Mengtian lab module, the final component of the space station, will be launched in October.

By that time, China's space station will be expanded from the foundational core module into a basic T-shaped three-module structure, with the core module Tianhe in the center and the two lab modules, Wentian and Mengtian, on each side of it.

Read more: What will China's space station be like once completed?

The Mengtian module is for microgravity science research and is equipped with multi-disciplinary laboratory cabinets for fluid physics, materials science, combustion science, basic physics and aerospace technology experiments.

Nearly 100 experiments are planned during the construction phase of the space station, said Lin Xiqiang, deputy director of CMS, at a press conference before the launch of the Shenzhou-14 crewed mission in June.

He said large-scale scientific research will be carried out after the operation is normalized. The research is expected to effectively promote breakthroughs in major frontier scientific fields, such as dark matter and dark energy, galaxy formation and evolution, the laws of nature and the sustainable development of the Earth.

(Top video by CGTN's Zheng Yibing. CGTN's Bu Shi also contributed to the story.)