China prepares for Mars sample return with HKU astrobiologist on mission team

China prepares for Mars sample return with HKU astrobiologist on mission team
by Riko Seibo
Tokyo, Japan (SPX) Jul 07, 2025

China has formally initiated its Tianwen-3 Mars Sample Return (MSR) mission, targeting a 2028 launch to collect and return Martian soil and rock for detailed study. Among the key contributors is Professor Yiliang LI, an astrobiologist at The University of Hong Kong (HKU), who leads a team focused on selecting a scientifically valuable landing site.

As a core member of the Tianwen-3 science team and co-author of a recent perspective article in Nature Astronomy, Professor LI supports China's search for biosignatures on Mars. The mission's central objective is to recover samples from environments likely to preserve signs of microbial life, if it ever existed on the Red Planet.

Mars, which resides within the solar system's habitable zone, is thought to have once hosted a warm, moist climate and a thick atmosphere. These early Martian conditions may have supported life, particularly extremophiles similar to those found in harsh environments on Earth. With Earth's own origins of life dating back 3.8 billion years, scientists are eager to compare both planets' evolutionary pathways.

The Tianwen-3 mission will deploy two rockets: one carrying a lander to gather Martian material, and another deploying an orbiter to retrieve and return the samples to Earth. Drilling operations will target depths of up to two meters, beyond the reach of harmful radiation and oxidants that may have degraded surface-level biosignatures. The samples will be transferred to the orbiter for return and then subjected to advanced terrestrial analysis.

One of the greatest challenges facing the mission lies in planetary protection. To mitigate the risk of Earth contamination by potential Martian life, China will establish a high-containment testing facility in Hefei. This site will screen the materials for any hazardous biological agents before releasing them for scientific study.

The Tianwen-3 project builds on China's previous Martian milestone: the 2021 deployment of its Zhurong rover. As the first mission to attempt a full sample return from Mars, Tianwen-3 positions China at the forefront of planetary science, especially as other international efforts remain in planning stages.

Research Report:In search of signs of life on Mars with China's sample return mission Tianwen-3