China plans to complete a geological map covering the entire surface of Mars by the end of 2028, as Beijing prepares for its next major Martian mission and expands its capabilities in planetary exploration.
Hou Zengqian, chief scientist of China’s Tianwen-3 Mars mission, announced the plan on Monday. According to state news agency Xinhua, the project will produce the first AI-driven geological map of Mars and is intended to establish a global reference for determining the geological ages of Martian formations.
The map will incorporate discoveries made by China’s Zhu Rong rover, which reached Mars in May 2021 as part of the Tianwen-1 mission. China became the second country after the United States to land a rover on Mars. Zhu Rong operated on the Martian surface for almost a year and travelled more than 1.9km.
Among the rover’s findings were indications that Mars may have once contained an ancient ocean on an intercontinental scale about 3.5 billion years ago, as well as evidence suggesting possible short-lived flooding around 1.6 billion years ago.
The mapping project will also produce a detailed geological map at a scale of 1:50,000 for the planned Tianwen-3 landing area, together with a series of geological atlases. Xinhua described the work as potentially providing a model for geological mapping of other planetary bodies, including the Moon, Venus and asteroids.
China plans to launch Tianwen-3 in late 2028, with the mission designed to collect at least 500 grams of Martian material and return the samples to Earth by around 2031. If successful, China would become the first country to complete a Mars sample-return mission.
The mission is planned around two launches. One spacecraft will carry a lander and an ascent vehicle to reach the Martian surface and collect samples. A second spacecraft will carry an orbiter and return module designed to transport the material back to Earth.
The timing places China’s programme against uncertainty surrounding the United States’ own Mars sample-return effort. NASA and the European Space Agency have faced rising costs and repeated delays in their joint programme. NASA’s Perseverance rover, which has operated on Mars since February 2021, has collected and cached several dozen rock and soil samples for eventual return.
Under the original programme, the samples were expected to reach Earth in the 2030s. NASA estimated in 2024 that the mission could cost as much as US$11 billion and that the samples might not return before 2040. In January, the US Congress cut funding for the existing programme, effectively ending its previous form.
Some funding has since been redirected towards a Mars Future Missions initiative intended to develop lower-cost technologies. The architecture and timetable for a future US Mars sample-return mission remain uncertain.
The United States has maintained a long lead in robotic Mars exploration. NASA’s Mariner 4 conducted the first successful Mars fly-by and returned close-up images in 1965, while Viking 1 became the agency’s first successful Mars lander in 1976.
The Sojourner rover became the first wheeled vehicle to operate on Mars in 1997. Since then, five American rovers have explored the Martian surface, with Curiosity and Perseverance continuing their missions.
China’s own Mars programme began with Tianwen-1, launched in July 2020. Zhu Rong completed its planned 90-Martian-day primary mission and continued operating until May 2022. It subsequently entered winter hibernation but did not resume operations, with reports attributing the failure mainly to heavy dust accumulation on its solar panels that restricted power generation.
