China Has Started Building a Rival to the ISS in Space

The Tiangong station will be key to China’s ambitious space program.

(Image courtesy of Spacewatch Global.)

(Image courtesy of Spacewatch Global.)

China recently launched the first module of its Tiangong (“Heavenly Palace”) station, which could compete with the aging International Space Station (ISS).

“A palace in the sky will no longer be just a romantic fantasy of the ancients,” said a Chinese state TV anchor describing the successful launch.

The launch created controversy: after reaching orbit and deploying the Tianhe (“Harmony of Heavens”) module, the core stage of the Long March 5B rocket fell in an uncontrolled reentry back to Earth, hitting the Indian Ocean uncomfortably close to the Maldives.

Tiangong is expected to need around 10 missions to bring components into orbit and assemble them into the final station, which Chinese authorities anticipate will become operational in late 2022. Once completed, it will remain in low Earth orbit.

The Tianhe module, which is the main component of the station, will house life support equipment and living quarters for the astronauts. The space station will be able to support three astronauts on a long-term basis, and up to six crew members for shorter missions. The crew will perform experiments and test technologies in the lab modules; analysts suspect that some of that work might be military research and development.

Two more Long March 5B rockets will carry the station’s laboratory modules, and other rocket variants will launch smaller parts. And China plans to launch astronauts into space for the first time in four years this June.

The Tianhe module is 54.4 feet long, has a diameter of 13.7 feet, and weighs almost 25 tons—making it the largest spacecraft China has ever constructed. It features 1,765 cubic feet of living space; if you add in the two lab capsules, the available square footage almost doubles. The core module has two berth ports that connect to the labs, as well as three docking ports for spacecraft and cargo. It also has an access port to allow astronauts to conduct space walks.

Once the labs are attached in 2022, Tiangong will form a “T” shape, with the core module in the middle and the labs docked around it. One of the labs, named Wentian (“Quest for Heaven”), will be used primarily for scientific and technological experiments. It will also serve as an emergency working and living shelter should the core module experience problems. It contains some of the management and control functions of the core module.

The second lab capsule, named Mengtian (“Dreaming of Heavens”), will likely function more like a pure research module, without the “lifeboat” capabilities of the Wentian capsule. It also comes equipped with a special airlock chamber that will allow astronauts to move cargo and instruments in and out of the module with the help of mechanical arms.

As a whole, the station will have 14 internal experiment racks and 50 external ports for studies of the space environment.

Scott Manley examines China’s ambitious new station.

The completed station will be roughly as big as the Cold War-era Soviet Mir station and only about a quarter of the size of the ISS. While its predecessors were prototypes that weren’t intended to last long, Tiangong is expected to last at least a decade—and odds are that it will be an increasingly important space asset for China.

China has been effectively barred from the ISS thanks to geopolitical tensions. In fact, if NASA wants to work with its Chinese counterpart, it will first need Congress to pass a law allowing it. American legislators point to concerns over intellectual property theft and industrial espionage as major obstacles to any attempts at cooperation.

And while Tiangong isn’t geared toward international collaboration like the ISS, China has said it is open to working with other nations on the platform. One catch to overcome: the Chinese docking mechanism differs from the one on the ISS, meaning that astronauts from other nations may have to travel to Tiangong on a Chinese vessel. This doesn’t seem to have dissuaded other nations, 17 of which have already committed to conduct experiments aboard the station.

The ISS is approaching the end of its service life: funding and partnership agreements run out in 2024, and NASA has only cleared the station to fly until 2028. The facility is facing an uncertain future now that Russia has announced its intent to withdraw from the program in 2025. It’s possible that, in a few years, China will have the only functioning space station in orbit!

The country has made no secret of its ambitions to challenge U.S. and Russian primacy in space. And while the latter nations have decades of experience, China is working hard to catch up. The first Chinese “taikonaut” went to space only in 2003. The space station will be another showpiece for China, which has bluntly stated its ambitions to become a “great space power,” according to Chinese President Xi Jinping.

“The successful launch of the Tianhe core module indicates that the construction of our country’s space station has entered the stage of full implementation and laid a solid foundation for subsequent missions,” said Xi. “The construction of a space station and the establishment of a national space laboratory … is an important leading project for building a powerful country in science and technology and aerospace.”

Read more about China’s ambitions in space at China: The Next Aerospace Superpower.