Tiangong Space Station

📷 China News Service / Wikimedia Commons (CC BY 4.0)

Tiangong (“Heavenly Palace”) is China’s permanently crewed space station: three connected modules orbiting about 390 km above Earth, hosting rotating three-person crews on roughly six-month tours. With visiting Shenzhou and Tianzhou spacecraft attached, the complex masses around 100 tonnes — about one-fifth of the International Space Station — and it was assembled with remarkable speed, going from first launch to finished T-shape in just 18 months across 2021-2022.

It is entirely Chinese-built and Chinese-run, the payoff of a three-step plan laid down back in 1992, and since the Shenzhou 14 crew arrived in June 2022 it has been continuously occupied.

Development History

China’s Project 921 plotted the route in 1992: first fly astronauts (Shenzhou, from 2003), then master spacewalks, dockings, and refueling using two small test labs — Tiangong-1, launched 2011, and Tiangong-2, launched 2016 — and only then build the real station. One reason China built its own outpost is that U.S. law, the 2011 Wolf Amendment, effectively barred it from the ISS partnership.

The station proper began on April 29, 2021, when the 22.5-tonne Tianhe core module rode a Long March 5B to orbit. The Shenzhou 12 crew moved in that June. The Wentian laboratory module docked in July 2022 and the Mengtian lab followed that October, swinging to a side port in November 2022 to complete the station’s distinctive T-shape.

Eighteen months from first module to completion compares with thirteen years of ISS assembly — though the ISS is five times heavier and needed over 40 launches versus Tiangong’s three.

Design & Capabilities

Each of the three modules is roughly 17 to 18 m long and 4.2 m across, together enclosing about 110 cubic metres of habitable space. Tianhe holds the crew quarters, galley, and station controls; Wentian carries life-science racks, the main crew airlock, and backup controls; Mengtian is a physics lab with a special airlock for pushing experiments and small satellites outside.

Two big flexible solar wings on each lab module power the station, and a 10-metre robotic arm — able to inchworm its way across docking points on the hull — handles cargo and assists spacewalkers. Distinctively, Tianhe carries Hall-effect ion thrusters alongside its chemical engines, the first electric propulsion ever used to keep a crewed spacecraft in orbit; sipping xenon, they offset atmospheric drag far more efficiently than chemical fuel alone.

Crews arrive on Shenzhou capsules and cargo comes on Tianzhou freighters, each delivering about 6.5 tonnes of supplies and propellant.

Life On Board & Operations

Three astronauts (taikonauts) live aboard at a time, briefly becoming six during week-long handovers between crews. Days follow Beijing time: experiments in space medicine, fluid physics, and precision timekeeping with cold-atom clocks, plus exercise, maintenance, and spacewalks from Wentian’s airlock. Crews have also broadcast live “Tiangong Classroom” science lessons to millions of schoolchildren — dissolving effervescent tablets in floating water spheres, to great effect.

Operations run from the Beijing Aerospace Control Center. China has announced plans to expand the station with additional modules, to fly the co-orbiting Xuntian space telescope (planned as of early 2026), and to host international researchers — experiments selected through a United Nations program are already aboard, and in 2025 China agreed to train Pakistani astronauts for a future visit.

Frequently Asked Questions

Is Tiangong bigger than the ISS?

No — it is much smaller. Tiangong masses about 100 tonnes with spacecraft attached versus the ISS’s 420, and offers roughly 110 cubic metres of habitable volume against about 900. But it is a generation newer: launched 2021-2022 rather than 1998-2011, with modern electronics, ion thrusters for stationkeeping, and far fewer launches needed to build it.

How many astronauts live on Tiangong?

Three at a time, on missions lasting about six months. During crew rotations the station briefly hosts six people for around a week while the outgoing crew hands over to the incoming one. Every crew so far has arrived on a Shenzhou spacecraft, which stays docked throughout the mission as their ride home and emergency lifeboat.

Why did China build its own space station?

Partly necessity, partly strategy. A 2011 U.S. law known as the Wolf Amendment barred NASA from bilateral cooperation with China, shutting it out of the ISS. China had in any case planned its own station since 1992, valuing independent capability. Tiangong now gives it a permanent orbital laboratory — and a platform it opens to international partners on its own terms.

How long will Tiangong operate?

The station is designed for at least ten years, with Chinese officials talking openly about fifteen or more plus possible expansion to six modules. If the ISS retires around 2030 as planned, Tiangong could for a time be the only fully operational government space station in orbit — unless commercial stations arrive first.