According to China's National Space Administration (CNSA) program, Planetary Exploration of China (Tianwen), the first Chinese rover to land on Mars may face difficulty in restarting itself after an extended hibernation period that lasted longer than anticipated since May of last year.
In July 2020, the Zhurong rover was sent to Mars as part of the Tianwen 1 mission. It successfully landed on the planet's surface on May 15, 2021. Three days later, on May 18, 2021, the rover entered sleep mode to conserve power during the winter. However, it was scheduled to awaken from its slumber in December of the same year but unfortunately failed to do so.
According to Zhang Rongqiao, the chief designer of China's Planetary Exploration program, the Zhurong rover appears to have accumulated dust on its surface, which has hindered its ability to generate solar power. This lack of power has resulted in the rover's inability to restart itself.
“When the dust accumulation on solar panels reaches 20 per cent, the rover’s power generation ability declines. When it reaches 30 per cent, the rover can generate power only if the sunlight is very strong. When it reaches 40 per cent, it may not wake up again,” Zhang said.
Zhang Rongqiao also mentioned that the Zhurong rover has been operational on Mars for 358 sols, equivalent to 367 Earth days. This exceeds the initial mission target of 90 days for the rover.
According to Asia Times, China's Planetary Exploration program's next Mars mission, Tianwen 3, is scheduled to be launched in 2028 and aims to deliver Mars samples to Earth by 2030 or 2031. If successful, this would be two to three years earlier than NASA's Mars Sample Return campaign, which intends to bring rock samples to Earth in 2033.
As per recent reports, Tianwen-3 is starting to come together, with more information becoming available. It has been reported that China plans to use its Long March 5 rockets to launch two vehicle stacks to Mars in a tandem launch.
The presentation slides, which were posted on the Chinese social media platform Weibo, show a small drone that looks like a helicopter and a six-legged robot, both related to the sample collection process for Tianwen-3.
Liu Jizhong and Hou Zengqian presented their plans for Tianwen-3 at the International Conference of Deep Space Sciences, stating that the combined lander and launcher will touch down on the Martian surface and collect up to 500 grams of material. The lander will then launch back into space with the collected samples.
The landing and ascent vehicles will be stacked together, while the orbiter and return craft will form another stack. The orbiter will remain in orbit around Mars and wait for the return vehicle to rendezvous with it for the transfer of the samples before returning to Earth.