China is set to expand its space station from three to six modules in the coming years and add a co-orbiting Hubble-class space observatory, even as the International Space Station approaches the end of its lifetime.
The three-module, T-shaped Tiangong space station was assembled in orbit across 2021 and 2022 and has hosted numerous three-astronaut Shenzhou crews, but China is now set to expand the orbital outpost with new modules, citing growing research demands and more frequent crew and cargo missions. As previously reported by Space.com, the planned expansion will see Tiangong grow into a “double-T” shape, with the addition of the multipurpose module and two new experiment modules, and allow China to extend the scale of operations aboard the station.
“This expansion has always been part of the original plan,” Qian Hang, a researcher with China Aerospace Science and Technology Corporation (CASC), told Chinese media. State media Xinhua reported that the first phase of the expansion will see the launch of a new 20-ton-class multifunctional module, which will dock with Tiangong’s Tianhe core module.
Additional docking ports on the new modules will allow Tiangong to welcome more spacecraft and provide greater operational flexibility when needed. “If the missions get more intensive, we risk ‘queuing’ for docking ports and lack sufficient emergency buffer space,” Qian said.
China is developing new, low-cost cargo options for Tiangong, while its new Mengzhou spacecraft, which could debut later this year, can carry seven astronauts to low Earth orbit. The Shenzhou spacecraft, which is currently used for China’s crewed missions, can carry three astronauts to Tiangong.
Before the arrival of a new module, however, the first new addition to Tiangong is expected to be Xuntian, a bus-sized space observatory with a 2-meter (6.6 feet) diameter primary mirror, slightly smaller than that of the Hubble Space Telescope.
Xuntian is scheduled for launch in 2027 and boasts a field of view around 300 times larger than that of Hubble, meaning it will be able to study and map around 40% of the heavens during its planned 10-year lifetime using its 2.5-billion-pixel camera. Xuntian will share a similar orbit with Tiangong, meaning it will be able to dock with the space station for maintenance, refueling, repairs and potentially upgrades.
China’s plans to expand Tiangong are coming at the same time as NASA is planning for the end of life of the much larger International Space Station (ISS). The agency plans to launch the SpaceX-developed U.S. Deorbit Vehicle (USDV) in the coming years, and drag the ISS into the atmosphere over the Pacific Ocean in late 2030 or early 2031.
While the U.S. is mulling a variety of plans for commercial stations that host astronauts in orbit after the ISS is retired, China would have the largest permanent outpost in orbit with Tiangong. According to Yang Hong, chief designer of the space station system, the planned expansion would take Tiangong from a mass of 90 tons to 180 tons.