On Nov 1, the Mengtian lab module (实验舱) successfully docked with (对接) China’s Tiangong space station. It took the building of the space station to the final stage, Xinhua reported. The docking took about 13 hours. At 17.88 meters long, the Mengtian lab module had a takeoff mass (起飞质量) of about 23 tons. It is the world’s heaviest single-body active spacecraft in orbit (在轨) right now. Together with the Tianhe core module and Wentian lab module, it has formed the space station’s T-shaped structure (结构).