China on Monday launched the space lab module Mengtian, taking construction of the country's space station Tiangong into final stage.

The Mengtian module, flying to join the two-module combination already about 400 kilometers above Earth, is the last "building block" that allows Tiangong to form a T-shape structure, the planned layout at the space station's completion.

The new combination is projected to take shape after a succession of elaborately-maneuvered tasks including the docking and the subsequent in-orbit transposition.

The Long March-5B Y4 carrier rocket, carrying Mengtian, 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.