Beijing, Jul 24 (IANS): China on Sunday launched Wentian, the first lab module of its space station.

The new module will function both as a backup of the core module and as a powerful scientific experiment platform, Xinhua reported.

Wentian, which literally means 'quest for the heavens', is the first of three modules planned for launch by China -- the core module, Tianhe, and two lab modules, Wentian and Mengtian.

The Tianhe module was launched in April 2021, and the Mengtian module is set to be launched in October this year.

The three together constitute the structure of China's Tiangong space station, is expected to be completed this year.

The Wentian module is 17.9 meters long, and has a maximum diameter of 4.2 meters, and a takeoff mass of 23 tonnes, according to Liu Gang, deputy chief designer of the China manned space program's space station system with the China Academy of Space Technology.

The Long March-5B Y3 carrier rocket, carrying Wentian, blasted off from the Wenchang Spacecraft Launch Site on the coast of the southern island province of Hainan, according to the China Manned Space Agency.

Together with a Shenzhou crew spacecraft and Tianzhou cargo vessel docked at the Chinese station, the completed Tiangong will be around 20 per cent as massive as the International Space Station (ISS), which has a mass of about 460 tonnes, Space.com reported.