China selects five international partners for Tianwen 3 Mars sample mission

Friday 24 - 16:40

China National Space Administration has chosen five international collaboration projects for its Tianwen 3 mission, a major step toward what could become the first successful return of Martian samples to Earth. The announcement was made during the opening of China’s Space Day in Chengdu, following a global call for proposals launched in April 2025.

The agency received 28 submissions and selected five based on scientific value, technical feasibility and readiness. The mission offers up to 20 kilograms of payload capacity for international partners, reflecting an effort to broaden global participation while maintaining tight engineering constraints for deep space operations.

Three instruments will be installed on the mission’s orbiter. These include a Mars PEX spectrometer developed under the COSPAR exploration panel to search for potential biosignatures and analyze surface composition. Additional payloads include a molecular and ion composition analyzer from the Macau University of Science and Technology to study atmospheric escape processes, and a laser heterodyne spectrometer from the Chinese University of Hong Kong to measure water isotopes and atmospheric dynamics.

The service module will carry a hyperspectral imager led by the University of Hong Kong, designed to map surface features, minerals and potential biological markers. The lander will include a laser retroreflector array developed by the Italian National Institute for Nuclear Physics, which will establish precise reference points on the Martian surface to support future measurements.

Tianwen 3 is scheduled for launch around 2028, with sample return expected near 2031. The mission architecture involves two launches using Long March 5 rockets to deploy an orbiter and return module alongside a lander, ascent vehicle and service module. The goal is to collect at least 500 grams of Martian rock and soil.

China currently faces limited competition in this area. The NASA Mars Sample Return program, once planned with the European Space Agency, has been halted after funding decisions in the United States. This leaves samples already collected by the Perseverance rover on Mars without a confirmed retrieval plan, while China moves forward with its own timeline.

The CNSA said the mission will continue under principles of equal cooperation, mutual benefit and peaceful use, positioning Tianwen 3 as both a scientific and diplomatic milestone in space exploration.