With the successful launch on Thursday of the Tianhe core module of the Chinese Space Station (CSS), China again demonstrated its aspirations to become a major contender in space. Riding atop a Long March 5B heavy lifter rocket launched from the Wenchang Satellite Launch Centre in Hainan, southern China, Tianhe (meaning “Heavenly Harmony”) is the starter phase of China’s first long-duration outpost for astronauts in space.
The arrival of Tianhe in orbit signals an aggressively paced schedule to finish construction of the station by late 2022, with two more launches scheduled for May and June. The latter will see three astronauts board the station for the first time, following their arrival and docking in a Shenzhou spacecraft.
Two smaller, temporary stations—Tiangong-1 and Tiangong-2—operated in orbit from 2011 to 2019, acting as testbeds for astronaut habitation and orbital rendezvous and docking. Tiangong-1 burned up during an uncontrolled loss of orbit over the Pacific in 2018, while Tiangong-2 was deliberately de-orbited in 2019.
China originally planned for the new station to begin construction in 2020. But turbopump exhaust problems with a Long March 5 rocket launched in 2017 forced a redesign and reengineering of one of the heavy lifter’s engines, delaying several projects.
Tianhe’s launch is the first of 11 planned assembly missions—four of which will involve astronauts—to deliver and connect multiple modules of the CSS. These include two scientific laboratories for research in such areas as protein crystallization, fluid dynamics, space combustion, and monitoring of cell growth in microgravity.
One planned highlight of the Chinese station project will be a co-orbiting Hubble-size space telescope equipped with a 2.5-billion pixel camera that gives it a reported viewing field 300 times greater than the 31-year-old Hubble observatory. The telescope module will be able to dock with the station for servicing. Chinese and international crews— European astronauts are now training in China—also are preparing for cooperative science missions on the station. China already has received more than 800 proposals for experiments from scientists worldwide.
The Chinese station follows a “less is more” model, in that it will have fewer modules than the International Space Station. Yet the Tianhe core module is bigger than any single ISS module, at 16.6 meters long and 4.2 meters wide, and weighs in at 22 metric tons. Tianhe accommodates living quarters for three astronauts at a time, and includes all control systems for power, propulsion, docking and life support.
The station’s architecture reflects something of a Russian approach. Tianhe emulates Russia’s Zarya Functional Cargo Block (FGB), the first major segment of the ISS launched in 1998. Attached to this core block will be two science labs, named Wentian (“Quest for the Heavens”) and Mengtian (“Dreaming of the heavens”). The station also will be equipped with a Russian Lyappa robotic arm similar to those on the Mir station of the 1990s. In all, Tianhe will have five functional docking ports, and multiple solar arrays for power.
Although Chinese scientists say the CSS is not intended to compete directly with the ISS, they do believe their station’s compact design—it weighs 66 metric tons compared to the ISS’s 450 tons and costs far less—will make it more efficient.
The CSS is a logical follow-on to the ISS, according to Xu Yuan Song, a General Director of the Asia- Pacific Space Cooperation Organization, who was interviewed on China’s CGTN network. By 2024, he said, “There will either be separation of the International Space Station or commercialization with no government support....The timing of the [Chinese] space station is good timing, a good connection with ISS. Once it’s done, we can invite international partners.” Although the United States has talked about ending the ISS program in 2024, that date is far from certain.
The U.S. Congress barred China from the International Space Station and all NASA-led space activities in 2011, citing national security concerns. Memories of that rejection, and the determination to advance in space independently, are still strong.
China’s achievements in space should not be discounted, says Leroy Chiao, a former NASA astronaut and International Space Station commander who tracks Chinese progress in human spaceflight. “The first reason any country gets into this business is for national prestige,” he says. “China is in this for the long haul. They want to be the leader in space exploration, and all areas of science. So expect the capabilities of their station to be significant.”
Dean Cheng, a senior research fellow at the Heritage Foundation in Washington, D.C., thinks that international cooperation will be a major focus. “What does the Chinese space station mean for the international scientific community?” he asks. “It will build China’s reputation, of course. The fact that the Chinese have generally been far less willing to share their data and typically release it months after the experiment or mission—unlike, say, NASA—is ignored by many observers.” Still, he says, “the Chinese will undoubtedly invite foreigners aboard the space station, and may do so early on. Its choice of astronauts will be picked as much for political as for scientific reasons.”
James Head, a Brown University planetary scientist who collaborates frequently with Chinese space scientists, called the launch of Tianhe a “momentous day for Chinese space exploration,” and a positive development in general. “Additional capability in low Earth orbit is very welcome, as there is a lot of important scientific research to carry out,” he said.