The China Space Station (CSS) consists of three modules and three ships again after the Shenzhou-16 manned spacecraft dockedwith the station's Tianhe core module through a docking port from below on Tuesday.

The station is orbiting the Earth some 400 kilometers above it. The Tianhe core module's two other docking ports are positioned in the front and the back, with the Shenzhou-15 manned spacecraft and the Tianzhou-6 cargo ship docked with them, respectively.

The core module has two berthing ports on the left and right sides, where the Wentian and Mengtian lab modules are located.

The configuration resembles the in-orbit transition phase between Shenzhou-14 and Shenzhou-15 on November 30, 2022, and it has a total mass exceeding 100 tonnes.

The Shenzhou-15 spacecraft will return to Earth after a brief handover with Shenzhou-16 in the coming days, and the China Space Station will return to its three-module and three-ship configuration.

This brings us to the Tianzhou-5 cargo spacecraft, whose launching and docking with the station were witnessed in November last year, as well as its undocking in early May to leave its port for its successor. Currently, it is flying alongside the CSS and will dock with the station after the return of the Shenzhou-15 spacecraft.

These cargo ships have more critical tasks than being simple couriers for space cargo. For example, the Tianzhou-5 will provide propellants, solar power and waste storage for the station in the coming months.

The three-module and three-ship configuration will remain in place for nearly half a year until the Shenzhou-17 manned mission. Looking ahead, the CSS will expand with additional modules.