Perseverance, a NASA robot, is due to land on Mars Thursday evening and attempt to find traces of ancient life there.
But the landing promises to be complicated, to such an extent that the maneuver is nicknamed "seven minutes of terror".
During these seven minutes, the robot must go from a speed of 20,000 km / h to almost zero.
After seven months of space travel, everything will be decided during a landing that promises to be perilous.
Thursday evening, Perseverance, a NASA robot, is to land on the planet Mars, in order to find traces of ancient life by collecting over several years up to thirty rock samples.
But the location chosen, Jezero Crater, is the most dangerous landing site ever attempted.
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Perseverance, a six-wheeled robot, is the largest robot ever to be sent to Mars.
It must land in the Jezero crater, therefore, which was in the past was a lake filled with water.
3 billion years ago, microbes, bacteria were able to develop, and there may still be traces.
This robot will therefore take samples in tubes, and we will try to bring them back to Earth in a few years.
"We must reduce speed at all costs"
But landing on Mars is very difficult.
We call this "the 7 minutes of terror".
One in two missions ends in a crash.
"It passes or it breaks. Everything is played in 7 minutes, everything is automatic", confirms to Europe 1 Francis Rocard, of the National Center for Space Studies.
"You get to 20,000 km / h, and you have to land at 1 or 2 km / h, so you have to reduce the speed at all costs."
For the first time on Mars, NASA will attempt to fly a helicopter.
A mission there too difficult, because the air on the planet is extremely light, and it is therefore necessary to build the lightest helicopter possible so that it can lift.
It ultimately weighs only 1.8 kg.
The Americans want to try to show that it is possible to fly on the red planet.