China is making progress on its Tianwen 3 Mars sample return mission, which aims to bring back to Earth roughly 500 grams (17.6 ounces) of Red Planet collectibles in 2031.
According to the China National Space Administration, the Tianwen 3 mission will have a lander, an ascender, a service capsule, an orbiter and an Earth reentry module.
If all goes to plan, Tianwen 3 will launch in 2028 on two Long March 5 heavy-lift rockets from the Wenchang Space Launch Site on the island of Hainan, China’s southernmost province.
Sputnik moment
“The Tianwen 3 mission is progressing smoothly, with intensified efforts being made to overcome technical challenges,” Hou Zengqian, the mission’s chief scientist, recently told CCTV, a state-run Chinese broadcaster.
“The probe equipment has entered the prototype development phase, and scientifically, many scientist teams from across the country are working together to tackle the challenges in accordance with the mission’s scientific objectives,” Hou added.
Meanwhile, NASA’s plans for hauling Mars samples to Earth are murky at the moment. So China appears to be in the lead to notch a major space milestone.
“If accurate, this represents a Sputnik moment,” said former NASA “Mars Czar” Scott Hubbard, referring to the reported Tianwen 3 progress.
“China will not only grab the headlines but may be the first to find evidence of life on another planet,” Hubbard, who also previously directed NASA’s Ames Research Center in Silicon Valley, told Space.com.
Top scientific priority
“The Tianwen 3 mission will look for microbial traces potentially similar to early forms of life on Earth, while also taking into consideration the possibility of unknown forms of life that may have emerged through Mars’ unique evolutionary history, providing crucial evidence to answer this major scientific question,” Hou told the state-run Xinhua news agency in a recent interview.
Searching for potential signs of life on Mars is the top scientific goal of the Tianwen 3 mission, Hou said on Sept. 3 during the 2026 International Deep Space Exploration Conference on, which was held in Hefei, the capital of eastern China’s Anhui Province.
Landing site
China’s Mars sample-return trek will be launched “around 2028” on two Long March 5 rockets departing from the Wenchang Space Launch Site in China’s southernmost island province of Hainan. (Launch windows for Mars missions come around just once every 26 months. The next one opens in November-December of this year, and the one after that, which Tianwen 3 apparently is targeting, runs from December 2028 to January 2029.)
Hou also said China expects to finalize the landing site for the mission by the end of 2026, with Chinese specialists advancing work on a next-generation geological map of Mars in its entirety.
If everything goes according to plan, the mission will collect samples from the Martian surface and then send them back to Earth around 2031.
“Regardless of whether signs of life are found, the returned Martian samples will have irreplaceable scientific value,” Hou said.
Tackle the challenges
Hou added that analyses of the returned samples at microscopic, molecular and isotopic scales could deepen our understanding of Mars’ geology and environment, as well as the evolution of habitability and the conditions under which life may originate.
According to Hou, Mars sample return is an extremely complex project, with landing-site selection, planetary protection and contamination control, and the identification of potential signs of life among its key challenges.
Chinese Mars researchers are selecting candidate landing sites for the mission based on factors that include geological age, history of water activity, habitability and the potential for preserving biosignatures.
Planetary protection lab
Xinhua reported last month that a “planetary protection laboratory” is to be built in the first phase of Hefei’s Deep-Space Science City in east China’s Anhui Province, citing the Deep Space Exploration Laboratory (DSEL).
“The planetary protection laboratory will implement a two-way protection system that guards both the returning Martian samples and Earth’s biosphere,” Xinhua reports.
The lab’s tasks encompass sample sterilization, unsealing, processing and biological risk assessment. “The facility is designed to support the implementation of major deep-space missions and to enable scientific research on Martian samples,” added Xinhua.
China “will follow the planetary protection policies of the Committee on Space Research, to prevent biological contamination of Mars by terrestrial organisms and to protect Earth from any potential extraterrestrial life forms that may be carried back in the samples,” said Li Hang, director of the development planning department at DSEL, according to Xinhua.
You can view a video about China’s Mars sample return plans here.
