China’s Tiangong Set to Become Cross‑Shaped Lab as ISS Heads for 2031 Retirement

TL;DR: China plans to add a fourth module to its Tiangong space station by 2027, turning the current T‑shaped layout into a cross‑shaped laboratory while the International Space Station is scheduled for retirement in 2031.

Tiangong became operational in 2022 and consists of the Tianhe core module plus the Wentian and Mengtian experiment modules, forming a T‑shape. It orbits at about 400 km altitude with an inclination of 41.6 degrees and is currently the only space station run by a single nation after China’s exclusion from the ISS program. The ISS, a multinational laboratory, is set to be de‑orbited in 2031 using a SpaceX‑provided vehicle.

The China Manned Space Agency announced in its 2023 mission plan that a fourth module, Mengtian‑2, will launch on a Long March 5B rocket and dock autonomously to the Tianhe core module’s radial port. This will reshape the station from a T‑shape to a cross‑shape, adding roughly 20 cubic meters of pressurized volume—an increase of about 18 % over the existing 110 cubic meters. The module will also provide two additional docking ports for cargo spacecraft and boost solar‑array power from 30 kW to 45 kW. Launch is slated for late 2027, with crewed visits beginning in 2028.

A larger, cross‑shaped Tiangong will accommodate more simultaneous experiments in fluid physics, materials science, and biomedical research, expanding the station’s scientific output. While the station remains Chinese‑led, the agency has expressed openness to foreign payloads and astronaut visits, potentially creating a new platform for international collaboration after the ISS retires. The shift also means that, for the first time since 2000, a single‑nation station will be the sole major laboratory in orbit.

What to watch next: the launch date of Mengtian‑2 in 2027, any announcements of partnership agreements with other space agencies or private firms, and the schedule of upcoming Shenzhou crewed missions that will test the expanded configuration.