When NASA receives the news that diligence entered the Martian atmosphere on Thursday, February 18, the rover’s destiny will already be sealed. In fact, TheThe radio signal he diligently emits travels at exactly 11 minutes and 22 seconds to travel at a speed of 205 million kilometers of light separating Earth from Mars. So the arrival of the mobile robot was made fully automated by NASA engineers. A visit to follow on Franceinfo.fr, NASA website Or, in French Cnes site.
Seven minutes before docking
Since its launch on July 30, 2020, the diligence has traveled 471 million kilometers, traveling at a speed of 85,000 km per hour. By the time it enters the Martian atmosphere, it has only fifty kilometers of descent to reach its exploration land.
But this seven-minute flight was the most dangerous of his long journey. At this point, the speed of the diligently moving capsule is still at 20,000 km / h. As the capsule sinks into the Martian atmosphere, its room temperature rises to more than 1,300 C. This friction capsule is greatly reduced with the atmosphere of the Red Planet as it is protected by its thermal shield.
Four minutes before docking
The speed of the capsule is reduced to 1,200 km / h, approximately the speed of sound. The capsule triggers its supersonic parachute from the rear top. This parachute was designed based on what was allowed Curiosity, The forerunner of perseverance, successfully landed on the Red Planet in 2012.
The canvas of this parachute is 21.5 meters wide, the equivalent of a large house, and uses within half a second. Back on board in the diligent traveling capsule: The on-board tool receives information about speed and altitude. So he can trigger a supersonic parachute at the right time. Reduces the speed of the braking capsule attached to the parachute to 300 km / h.
Two minutes before docking
The most dangerous stage has not yet come. At an altitude of 4 km above the surface of Mars, the rover and its ski crane (named after its space crane) are dropped from the capsule, which has been flying for almost seven months. After a while, the Sky Crane eight retrocketts gradually reduce its speed to 30 km / h, stabilize the engine and position itself at a height of 20 m from its landing, which is located in the Jessero abyss.
In 30 seconds, diligence will touch the Martian soil. Thanks to three nylon cables, the diligent Sky Crane lays slowly on the ground of Mars for $ 2.5 billion. The cables must then be separated from the rover as soon as possible. The danger is that he will be dragged by a flying crane. It is planned to crash a few tens of meters away.
After 11 minutes, NASA scientists will see if the rover can begin its mission: to search for clues to ancient life on the Red Planet.