Tiangong is China’s crewed space station, a facility in low Earth orbit built from three modules and finished in 2022. Its name means “heavenly palace.” It orbits about 400 kilometers up, on a path similar to the International Space Station, and hosts rotating crews of Chinese astronauts, called taikonauts, who live aboard for months at a time. China runs it alone, without the multinational partnership behind the ISS.
The station is the most visible part of China’s civil space program, covered more broadly on our China space program page. Tiangong is smaller than the International Space Station that shares its orbit, yet it gives China something no other single nation runs: a permanently crewed outpost under its sole control.
The Three Modules
Tiangong is assembled from three main modules that form a T-shape in orbit. Each was launched separately on a heavy rocket and joined in space. The layout gives the crew living space, laboratories, and multiple docking ports for visiting craft.
- Tianhe, the core module. Launched in 2021, Tianhe is the heart of the station. It holds the crew’s living quarters, the main control systems, the propulsion to keep the station in orbit, and the primary docking ports. A crew can live in Tianhe alone, which is how the first taikonauts began occupying the station before the labs arrived.
- Wentian, the first lab. Added in 2022, Wentian carries science racks for biology and life-sciences experiments and a second set of life-support gear that backs up the core. It also has an airlock built for spacewalks and a small robotic arm.
- Mengtian, the second lab. Also added in 2022, Mengtian holds experiments in physics, materials science, and fluid behavior in microgravity. It includes an airlock designed to pass small payloads outside the station without a spacewalk.
Together the three give Tiangong the room and equipment to run continuous research with a crew aboard.
Life and Science Aboard
Tiangong operates with a standing crew, normally three taikonauts, who rotate on missions lasting about six months. Crews overlap briefly during handovers, so the station stays occupied. The astronauts run experiments, maintain the station, and perform spacewalks to install or repair equipment on the outside.
The science covers several fields. Crews study how living things, from cells to plants, respond to long spells in microgravity, work that informs future long-duration flight. Other experiments look at how materials form and how fluids behave without gravity, conditions impossible to reproduce fully on Earth. The station also carries a separate space telescope program: China plans a large survey telescope, sometimes called Xuntian, to fly in the same orbit and dock with Tiangong for servicing.
Tiangong also has a large robotic arm mounted on the core module. It helps move visiting modules, assists taikonauts on spacewalks, and can inch along the station’s exterior to reach different points. Because an arm that can grapple and reposition heavy objects has obvious dual uses, some outside analysts watch its capabilities closely. China has designed the station for an operational life of at least a decade, with room to add more modules over time.
Why China Built Its Own Station
China built Tiangong because it was effectively barred from the International Space Station. A 2011 U.S. law, often called the Wolf Amendment, restricts NASA from most direct cooperation with Chinese government entities. That kept China out of the ISS partnership, which is led by the United States and includes Russia, Europe, Japan, and Canada.
Faced with exclusion, China chose to build rather than sit out. Developing an independent station gave it full control over who flies, what science runs, and when crews launch, with no dependence on another nation’s rules or schedule. The result is that, as of 2026, two crewed stations share low Earth orbit, run by programs that do not cooperate. When the ISS is retired later this decade, Tiangong could become the only permanently crewed station in orbit for a period, unless commercial stations arrive on time.
How Tiangong Compares to the ISS
Tiangong and the International Space Station serve similar purposes but differ sharply in scale and structure. The ISS is far larger, assembled over more than a decade from over a dozen major modules by a partnership of nations. Tiangong is a leaner three-module design meant to do focused research at lower cost, and it was completed in about a year and a half of module launches.
The table below sets the two side by side on the points that matter most.
| Feature | Tiangong | International Space Station |
|---|---|---|
| Operator | China, alone | Partnership of the U.S., Russia, Europe, Japan, Canada |
| Major modules | Three | More than a dozen |
| Typical crew | Three | Six or seven |
| Relative size | Roughly a fifth to a quarter of the ISS | The largest structure ever built in space |
| First occupied | 2021 | 2000 |
The comparison is not really about which station is bigger. The ISS reflects a post-Cold War moment when former rivals pooled money and hardware. Tiangong reflects a later moment when China, shut out of that project, decided to run its own. The smaller size is partly budget and partly design: China built the station it needed rather than the largest one possible, and it left room to add modules later.
International Access
China has signaled that Tiangong is open to other nations, within limits it controls. Working through the United Nations Office for Outer Space Affairs, China selected a set of international experiments to fly aboard the station, chosen from proposals by research teams around the world. This lets foreign scientists run work on Tiangong without a partnership stake in it.
Crewed access is a further step China has said it is open to. As of 2026 every Tiangong crew has been Chinese, but officials have stated that foreign astronauts could fly in the future, arranged through China. That model differs from the ISS, where crew slots follow from each partner’s contribution. On Tiangong, China holds the station and decides who visits.
To see where the station fits in China’s wider push into space, and how it sits against rival programs, read our China space program page and our Russia space program page.