A senior space official has confirmed China plans to bring rocks home from the surface of Mars by 2031, which could make it the first nation to deliver Martian samples to Earth.
The timeline is two years ahead of a US-European planned Mars mission to return samples to Earth, according to Sun Zezhou, chief designer of China’s first Mars mission Tianwen 1 as well as the Chang’e 3 and Chang’e 4 lunar missions.
China aimed to send two spacecraft – one comprising a lander and ascent vehicle, and the other an orbiter and re-entry capsule – to the red planet in 2028, Sun said on Monday during a talk to celebrate the 120th anniversary of Nanjing University.
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After the lander touches down, it will drill for samples and scoop them up. The rocks will be delivered into Mars’ orbit and the mission will head home around October 2030, arriving on Earth in July 2031.
Retrieving samples from Mars to study in a laboratory had long been the dream of planetary scientists around the world, Sun said.
Now, his team is developing the key technologies needed to carry out the complex task. For instance, compared with Tianwen 1, atmospheric entry will be more challenging because the mass and velocity of the spacecraft will increase significantly. It could easily burn if not well shielded, or crash if the parachute does not work properly.
The team has yet to decide whether to use solid or liquid propellant to lift off from Mars to meet a velocity increase of 4.5 kilometres per second (2.8 miles per second) and a -60 degree Celsius (-76 Fahrenheit) environment.
Sun said the team was also debating the specific timing of launching the two probes.
“If both are sent during the November-December 2028 launch window, we’ll land into a dust storm season which makes our job very tough over there,” he said.
“If the lander and ascent vehicle combination was launched a little earlier, say May 2028, it would take much longer to arrive at Mars but avoid the bad weather.”
Typically, the launch window of a space mission is calculated to ensure it reaches the orbit or destination without missing the target. For example, a launch window to travel to Mars opens every 26 months, remaining open for about four weeks.
There is a similar launch window when the spacecraft returns to the Earth from Mars, further complicating the design of a sample return mission.
China was a latecomer to Mars exploration, Sun said, but now had a role to play in the global arena thanks to technological foundations built on decades of moon exploration.
In July 2020, China launched its first Mars mission, Tianwen 1, including an orbiter, a lander and a rover carrying a total of 13 scientific instruments. The landing occurred safely on the Martian plain Utopia Planitia the following May.
In late 2021, the Chinese government declared Tianwen 1 a success. Sun said that so far, the orbiter had finished a global remote sensing survey of Mars, while the Zhu Rong rover had travelled 1.921km south of its landing point.
Meanwhile, the United States has been working with the European Space Agency (ESA) to develop an even more complex mission to bring back samples from Mars, some of which are now being collected by Nasa’s Perseverance rover.
Only a few countries in the world have successfully explored Mars. In addition to the US and China, the former Soviet Union, ESA, India and the United Arab Emirates have sent orbiters to the red planet.
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