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.

The Wentian module is 17.9 meters long, has a maximum diameter of 4.2 meters, and a takeoff mass of 23 tonnes.

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.

The construction of China's Tiangong space station is expected to be completed this year. It will then evolve from a single-module structure into a national space laboratory with three modules -- the core module, Tianhe, and two lab modules, Wentian and Mengtian.

The mission marked the 428th flight of the Long March carrier rockets.