China’s Rover Completes its Primary 90-day Mission, but it Still has More Science to do

Three months after touching down on the Martian surface, China’s Zhurong rover has completed its primary mission and is still going strong.

The ambitious robotic exploration vehicle launched on a Long March-5 rocket from Wenchang, China back in July 2020, along with an accompanying Mars orbiter. After a 6.5 month journey, the spacecraft arrived at Mars in February.

Unlike recent NASA missions to Mars, which perform their Entry, Descent, and Landing procedures immediately, Zhurong stayed in orbit for several months before landing. The wait allowed the team to gather data about the health of the vehicle, move it into the most advantageous orbit, and decide on a landing zone.

The decision to take their time with the landing makes sense: Mars is a notoriously difficult place to land safely. About half of all historical Mars landing attempts have ended in failure, and until Zhurong, only the United States had ever succeeded (it might be argued that the Soviet Union’s Mars 3 and the United Kingdom’s Beagle 2 landers both soft-landed successfully, but both vehicles also broke down seconds after landing).

Zhurong’s landing site as seen from orbit. Taken by the HiRISE camera on the Mars Reconnaissance Orbiter on June 11, 2021. Credit: NASA/JPL/UArizona

In any case, Zhurong’s cautious approach paid off, and it successfully touched down on May 14th, 2021. Its landing site is in the region known as Utopia Planitia, a wide rocky plain, parts of which were previously explored by the Viking 2 Lander in 1976. Utopia Planitia is a desirable landing site because its flat, open terrain makes for an easier touchdown, but also because it is believed to be an ancient lakebed, giving the region scientific value to researchers hoping to learn about water, or even life, on ancient Mars.

Since landing, Zhurong has traveled 886 meters, stopping to take scientific measurements, and some selfies, along the way. The rover carries a ground-penetrating radar system which, along with a similar system onboard NASA’s new Perseverance rover, is the first of its kind on Mars. Several other instruments will enable it to carry out geological investigations.

Zhurong takes a photo of itself and its lander with a detachable camera. Credit: CNSA.

As Zhurong is China’s first Martian rover, part of the primary mission involved testing the vehicle’s design and engineering: learning how to land on Mars and navigate a robotic rover there is a feat in itself. As part of this technology demonstration campaign, one of the rover’s first targets was its own discarded parachute and backshell, which were intentionally detached as part of the landing procedure. The rover drove up to the backshell and inspected it, taking photos to send back to the team.

Zhurong approaches its own backshell and parachute, discarded during landing. Credit: CNSA.

This week, the China National Space Administration announced that both the scientific and engineering goals of Zhurong’s 90-day primary mission had been achieved. So far, Zhurong seems to have been a resounding success. The rover appears healthy and will continue to explore the surrounding region in the months to come. It has returned 10 gigabytes of scientific data so far. Hopefully, this and future data collected by the rover can help broaden our understanding of the red planet.