Tiangong-3

Tiangong-3 was a proposed Chinese space station that was part of the Tiangong program. The China National Space Agency initially planned to launch Tiangong-3 around 2015, following the launch of the Tiangong-2 test laboratory, which was originally planned for 2013. However, the goals for the Tiangong-2 and Tiangong-3 laboratories were merged, and the latter was not ordered. Eventually, the first module of the third station of the Tiangong program, Tiangong space station, was launched in 2021.

Development

In 2008, the China Manned [Space Engineering Office] published a brief description of Tiangong-2 and Tiangong-3, indicating that several crewed spaceships would be launched in the late 2010s to dock with Tiangong-3. The first Tiangong module, Tiangong-1, was launched in September 2011 and successfully docked with the uncrewed Shenzhou 8 spacecraft in November 2011, marking China's first orbital docking.

Tiangong-3 was expected to provide:

Unaided 40-day habitability for three astronauts.
Testing for regenerative life-support technology and verification of methods of orbital replenishment of propellant and air.
A multi-docking berthing mechanism, allowing up to two spacecraft to dock with it simultaneously.