What Does China's New 'Heavenly Palace' in Space Mean for the ISS?

Many in the U.S., though, see Tiangong as an ominous development. An April 2021 threat assessment by U.S. intelligence agencies portrays the station as another step in the Chinese government's efforts "to match or exceed U.S. capabilities in space to gain the military, economic, and prestige benefits that Washington has accrued from space leadership." Washington Post columnist James Hohman portrayed the station as part of a "the new space race" that endangers U.S. national security. Some note that China is building the new orbital outpost at a time when the International Space Station, which has been hosting astronauts from the U.S., Russia and other countries for more than two decades, is starting to show its age. (China can't send its astronauts to the ISS, thanks to a 2011 U.S. law that bars any American cooperation with the Chinese space program due to fears of technology theft or risks to national security.)

But while Tiangong might boost Chinese's prestige as a spacefaring nation, space experts don't see it as an achievement on the scale of the ISS. They note that Tiangong will be a fifth the size of the ISS, which is as big as a football field, and that the Chinese newcomer actually emulates an older, simpler design.

"The Chinese station is more comparable to the old Soviet Mir Station than the much larger International Space Station," explains Scott Pace, director of the Space Policy Institute in the Elliott School of International Affairs at George Washington University, in an email. "The Chinese station does not represent a significant technical advance over the ISS."

"This is not the ISS," says Jonathan McDowell, in an email interview. He's an astrophysicist at the Center for Astrophysics Harvard & Smithsonian and creator of Jonathan's Space Report, who emphasizes that he speaks independently and not for the center. "This is a pretty direct copy of the 1980s Mir station that the Soviets launched, though it's improved. Look at the drawings for the two. It's really hard for the lay person to tell them apart."

In some ways, Tiangong is sort of the latest on China's list of things it needs to do to catch up to the U.S. and Russia, after choosing to wait until the 1990s to make a strategic investment in space exploration and not launching a manned space flight until 2003. "They've had their first astronaut, their first moon probe, and their first spacewalk," McDowell explains. "They're gradually ticking them off. The remaining things they haven't done include long-duration space station stays, and astronauts on the moon. They're maybe 10 years in the future on that one."

China's space strategy is to achieve milestones that are comparable to the U.S., even if they don't quite match the level of technological sophistication, according to McDowell.

Even accomplishing rough parity hasn't been easy. In order to put Tiangong's modules into space, China needed to develop a new generation of heavy-lift rocket, the Long March 5. After a prototype suffered a critical failure during a 2017 launch, the launching of the Tiangong's core module, originally scheduled for 2018, was pushed back until this year, according to this recent analysis from the Center for Strategic & International Studies.

"They were years late in getting operational," McDowell says.

But while experts suggest that the Tiangong's main purpose is to establish China as a spacefaring power, the space station has the potential to achieve some scientific and technological advances.

If the Chinese put their planned space telescope, which is scheduled for launch in 2024, at the same orbital inclination as the Tiangong, that would make it possible for Chinese astronauts to travel to the satellite in some sort of ferry spacecraft and make repairs and upgrades easily.

"Although the fundamental goals of the Chinese station are geopolitical in nature, the association of the station with a Hubble-class-plus space telescope promises a wealth of new scientific discoveries," notes Dale Skran, chief operating officer for the National Space Society, a nongovernment organization that advocates for U.S. space exploration efforts, in an email. "In addition, the ability of the Chinese station's robot arm to 'walk' to any location on the station is an interesting development."

The Chinese space station, along with other Chinese successes such as the Zhurong Mars rover, may also help to invigorate the U.S. space program. In May, the Biden administration's new NASA chief, Bill Nelson, pointed to recent Chinese achievements in his efforts to get Congress to fund NASA, as this Spaceflight Now article describes.

The Chinese station may have an impact upon the future of the ISS. "The Chinese station in orbit makes a U.S. retreat from the ISS politically untenable," explains Skran. "There will be stronger support to extend the life of the ISS, and, NSS (National Space Society) hopes, greater understanding of the need to enable a gapless transition to future commercial LEO (low-Earth orbit) stations."

Current agreements between the ISS partner stations envisioned the station lasting until 2024, but negotiations are underway to extend the mission, and NASA administrator Nelson has said that he hopes to keep the ISS operating until 2030. But as Pace notes, the aging station won't last forever.

"The life span of the ISS will most likely be driven by aging of some irreplaceable elements, such as the Russian modules Zarya and Zvezda, which were originally designed for the Soviet Mir-2 space station." Pace explains.

Instead of building another ISS, NASA is looking at the possibility of replacing it with stations owned by commercial space companies in low-Earth orbit, according to Space.com.