China’s growing presence in space has been undeniable since the turn of the century. Between sending the first “taikonaut” to space in 2003 (Yang Liwei), launching the first Chinese robotic mission to the Moon (Chang’e-1) in 2007, and the deployment of their Tiangong space station between 2021-2022, China has emerged as a major power in space. Accordingly, they have bold plans for the future, like the proposed expansion of their Tiangong space station and the creation of the International Lunar Research Station (ILRS) by 2035.
In their desire to become a space power that can rival NASA, China also has its sights on Mars. In addition to crewed missions that will culminate in a “permanent base,” they intend to conduct a sample-return mission in the near future. This will be performed by the Tianwen-3 mission, which is currently scheduled to launch in 2028 and return samples to Earth by 2031. In a recent article, the Tianwen-3 science team outlined their exploration strategy, including the methods used to retrieve the samples, the target locations, and how they’ll be analyzed for biosignatures that could indicate the presence of past life.
Zengqian Hou was the article’s lead author, a geologist with the Deep Space Exploration Laboratory (DSEL) and the Chinese Academy of Geological Sciences (CAGS), and the mission team supervisor. His fellow team members included the mission’s chief designer, Liu Jizhong, and colleagues from the DSEL, the Lunar Exploration and Space Engineering Center, the Chinese Academy of Sciences (CAS), and the University of Science and Technology of China (USTC). The article was recently published in the November edition of National Science Review.
This mission is the third in China’s Tianwen (Chinese for “questions to heaven”) exploration program. The previous mission (Tianwen-1) included an orbiter, a lander, and the Zhurong rover, which reached Mars in February 2021. The successful deployment of this mission made China the third nation (after the Soviet Union and the U.S.) to land on Mars. Highlights of the mission include the mapping of the entire Martian surface by the orbiter and the discovery of hydrated minerals by Zhurong, further confirming that Mars once had liquid water on its surface.
News of this latest mission was first shared by Jizhong at the 2nd International Deep Space Exploration Conference, which took place from September 4th to 7th in Huangshan City, China. However, few details were shared at the time, though a concurrently published paper suggested that the mission could include a helicopter similar to NASA’s Ingenuity. According to the latest from Jizhong, the Tianwen-3 will consist of two launches sometime in 2028 using the Long March 5 (CZ-5) rocket. While one CZ-5 will send the orbiter/return vehicle, the second will send the lander/ascent vehicle. As Liu told the state-owned news agency Xinhua:
“China has retrieved the first-ever samples from the far side of the moon with the Chang’e-6 mission this year. Since Mars is much farther away than the moon, it will take two launches to carry out the Mars sample-return mission due to the limited carrying capacities of our current rockets. Two Long March-5 carrier rockets will be used for the mission.”
Other details include the 86 potential landing sites proposed by the team, which are primarily concentrated in the ancient Chryse Planitia and Utopia Planitia regions. These areas are considered good places to search for potential biosignatures that could be preserved remains of ancient life. This includes features that indicate the presence of past water, including delta fans, lake beds, and the coastline, suggesting the presence of a past ocean in the Northern Lowlands. The team also stated that Tianwen-3 will carry payloads developed with international partners.
They also stressed the necessity for new instruments specifically designed to detect biosignatures. To this end, they have developed a 13-phase mission plan that leverages in-situ and remote-sensing detection technologies. Liu also disclosed that the mission will rely on multi-point surface sampling, fixed-point in-depth drilling, and in-flight vehicle sampling to obtain diverse samples. They also state that China will conduct joint research with scientists worldwide on Mars samples and detection data.
What is clear from this latest news is that China intends to preempt NASA and the ESA’s proposed Mars Sample Return (MSR) mission. Due to budget cuts announced earlier this year, this mission is currently stuck in the design phase. Similarly, China has indicated that the Tianwen-4 mission will explore the Jupiter system to learn more about its moons and their evolutionary history. This mission is scheduled to launch in September 2029 and will follow on the heels of NASA’s Europa Clipper and the ESA’s JUpiter Icy Moons Explorer (JUICE).
This is in keeping with China’s pattern of following in NASA’s footsteps, catching up with them and surpassing them as the leader in space exploration. If they manage to return Martian samples to Earth before either NASA or the ESA, they will have accomplished a task no other space agency has. However, given the scientific value of these samples and the international cooperation that will go into their analysis will be to the benefit of all.
If the “in-depth drilling” rivals the drilling depth of the Rosalind Franklin rover of ESA’s ExoMars program – the biosignature detection suit will rival or surpass – it will go to-to-toe with the other non-chinese martian exploration effort as well.