According to the team, the last, technically very demanding phase of the flight from entering the upper atmosphere through the descent to landing was the “seven horror minutes” of waiting in the control center. It was a series of consecutive automatic actions, the only failure of which could mean destruction. Only 40 percent of Mars missions to date have been successful.
Source: Youtube
The heat shield of the protective case, which hid Perseverance, had to handle a fire of up to 1,300 degrees Celsius during the descent. At the right time, when the initial descent speed dropped from 20,000 kilometers per hour to 1,600 kilometers, the parachute had to open and then separate the heat shield. Eventually, at a height of several meters, the descending section lowered the rover with ropes to the planet’s surface and then flew to a safe distance.
In addition, it was necessary for small engines and aiming devices and cameras to function properly to guide them to a specific safe landing site in the selected area.