Where did the Chinese nation come from

China's Mars missionUS rovers face competition

At the beginning it still flies at almost five kilometers per second. When Tianwen-1, China's first Mars probe, releases its lander Zhurong, it is initially well protected in a cone-shaped, white capsule. The engineers in the Beijing control room are now flying blind.

"The big problem is the distance to Mars. That restricts the exchange of data. We have to preprogram all the actions in one go, but we'll only find out later whether the execution worked." That said Teng Baoyi, deputy chief designer of the China Aerospace Science and Technology Corporation, the television broadcaster CCTV.

(CNSA) Chinese moon mission to bring rocks to earth
The astronauts of the Apollo missions and unmanned Soviet Luna probes brought rocks from the moon to earth in the 1960s and 1970s. With the "Chang'e 5" mission, China now also wants to bring lunar material to earth. The mission is named after the Chinese goddess of the moon.

China has already landed a total of three probes on the nearby Earth's moon via radio link - on Mars, which is much further away, nothing can be controlled remotely: one after the other, the heat shield has to brake the landing probe. Then the parachute has to open at the right moment before a rocket engine finally stops the exposed landing gear in the air just above the ground and the lander automatically searches for a landing site away from large boulders. All of this is a risk. Never before has a nation tried to master all of these steps at the same time the first time.

Twice as heavy as the jade bunny

The landing area is in the northern lowlands of Utopia Planitia, where the US lander Viking 2 touched down in 1976, explains the planetary geologist Ernst Hauber from the German Aerospace Center: "They looked for suitable landing sites. And because Utopia Planitia is relatively deep and you have a lot of atmosphere for the parachute descent and because it is relatively flat it was a safe landing site. That is also part of the reasons why Tianwen will land there now. "

Like the rover Jade Hare on the moon before, Zhurong is also supposed to descend from his landing platform via a ramp. The Mars rover has six wheels and weighs 240 kilograms, twice as much as the jade hare. Zhurong carries six instruments, including several cameras, a weather station, a magnetometer, and a laser spectrometer.

Mystery in the deep: permafrost

One of the mission's scientific goals: The rover is to explore Mars' humid past. In Utopia Planitia there is permafrost, that is, huge structures criss-crossed by cracks, under which a lot of water ice is suspected. The sixth instrument on board is particularly important for this: a radar.

Ernst Hauber: "ESA's ExoMars rover, which will land in two years' time, has something like that on board. But the Chinese rover also has something on board. And if there is ice or water underground, then such a ground penetration radar can to a depth of a few meters to ten meters. "

Where does so much water ice come from?

The amount of water assumed in the depth corresponds to 250 times that of Lake Constance. But when Viking touched down here 44 years ago, the ice was still unknown. How it got here is still unclear.

Hauber: "The important thing is that it would probably not happen under the current climate. So one would have to assume climate fluctuations in recent Martian history. One also has ideas why this could have happened, for example, that the rotation axis of the planet changes its inclination and that it causes climate change. "

Whether Zhurong can clarify this question depends on many unknowns: The Chinese engineers first have to prove that they can not only safely drop off a lander, but also operate it for three months as planned. Because, apart from the USA, nobody has yet succeeded in doing this either.