It docked the same day. Mengtian reached the forward port of the Tianhe core module about thirteen hours after launch, and the engineers on the ground were keen to move it quickly, because the L-shaped station that existed in the meantime was awkward to hold steady and used more propellant than the finished shape would.
Then it shifted. On November 3 the module was swung by its indexing robotic arm from the forward port to the port-side berth, a manoeuvre that lasted about an hour, and the station took on the T shape it had been designed to have, with two laboratory modules flanking the core.
The shape became a T. With Mengtian in place the station reached its full configuration: three modules roughly 60 metres across, with a mass near 70 tonnes before visiting spacecraft, solar arrays on every module and a permanent home for three crew with room for six during handovers.
Mengtian is built around experiments. It carries 13 internal experiment racks and 37 external adapters, with work concentrated in microgravity physics and materials science: fluid behaviour without convection, combustion, and the growth of crystals and alloys in conditions that cannot be reproduced on the ground for long.
Its most distinctive fitting is a cargo airlock, a hatch through which payloads can be moved from the pressurised interior to the outside of the station without an astronaut going out first, which is what makes it possible to fit and retrieve external experiments on a schedule instead of only during spacewalks.
Building was finished. The assembly had taken about eighteen months from the launch of the core module in April 2021, across eleven launch missions with crews, freighters and modules, and it gave China a station that it will operate alone if the International Space Station retires around 2030 as planned.
The first crewed flight to the completed station followed within a month, and the programme has since moved from construction to routine operation: six-month crew rotations, cargo flights, an expanding list of experiments, and plans to grow the station from three modules to six.