China opens international payload opportunities for Mars sample return mission

China opens international payload opportunities for Mars sample return mission
by Simon Mansfield
Sydney, Australia (SPX) Apr 28, 2025

China has officially called for international participation in its upcoming Mars sample-return project, Tianwen 3, the China National Space Administration (CNSA) announced on Thursday.

During a ceremony in Shanghai celebrating the 10th Space Day, CNSA revealed that it is inviting foreign scientists to contribute scientific instruments to be flown aboard the Tianwen 3 spacecraft.

According to recently released mission details, Tianwen 3 will consist of five primary segments: a lander, an ascender, a service capsule, an orbiter, and a reentry module. The mission is targeted for launch around 2028, utilizing two Long March 5 heavy-lift rockets from the Wenchang Space Launch Center in Hainan province.

The lander, ascender, and service capsule will first cruise along an Earth-Mars transfer trajectory, executing orbital corrections en route. Upon arrival at Mars, they will enter orbit and subsequently separate. The lander and ascender will attempt a powered soft landing on the Martian surface, while the service capsule, designed primarily to support the trip, will also host scientific instruments.

Meanwhile, the orbiter and reentry module will establish their own orbit around Mars to support communications and wait for the retrieval of Martian samples.

After collecting surface materials and sealing them in a vacuum metal container, the ascender will launch into orbit to rendezvous and dock with the reentry module.

Following a successful transfer of the samples, the ascender will separate. The orbiter and reentry module will then depart Mars orbit and set course for Earth. As they approach Earth, the two will separate, and the reentry module will execute precision maneuvers to land at a predetermined recovery site.

If successful, Tianwen 3 would achieve the historic feat of returning Martian samples to Earth for the first time, offering scientists unprecedented material for studying potential past life, analyzing Martian geology and interior structure, and understanding atmospheric processes.

CNSA's announcement also noted that 15 kilograms of payload space on the orbiter and 5 kilograms on the service capsule have been reserved for international scientific instruments. Interested parties are encouraged to review the full technical requirements, now available on the CNSA's official website.

China's first mission to Mars, Tianwen 1, launched in July 2020 and successfully delivered a lander and the Zhurong rover to the Martian surface by May 2021, marking China's entry into interplanetary exploration.