In the early morning of February 19, Beijing time, the U.S. willpower probe successfully landed on Mars!
During the 2020 window period, mankind launched three probes to Mars, namely, the United Arab Emirates hope, China tianwen-1 and the United States perseverance.
Among them, the hope carried out the circumferential exploration mission and started the circumferential fire on February 9, 2021; the willpower carried out the landing patrol exploration mission.
Tianwen-1, China's first Mars exploration mission, has now entered the orbit of circumfire, and plans to land on Mars from May to June 2021.
Image of Mars capture process of tianwen-1 spacecraft (image of directional antenna surveillance camera)
You must wonder: Why did willpower land directly when it reached Mars, while tianwen-1, which arrived earlier, had to orbit Mars for about three months before landing?
It is precisely because of its special mission that the tianwen-1 probe, which has both a orbiter and a patrol group, has become one of the heaviest probes launched by human beings to Mars, reaching more than 5 tons. At the same time, it has a maximum diameter of about 4 meters and a height of more than 4 meters.
On February 15, the tianwen-1 spacecraft adjusted its orbit to a ring fire orbit passing through the poles of Mars.
In the future, the tianwen-1 probe will enter the Mars docking orbit after several orbit adjustments to carry out exploration in the pre selected landing area. It is planned to select a plane to carry out Mars landing and patrol exploration from May to June 2021.
In the previous Chang'e lunar exploration mission, China has achieved soft landing on the lunar surface for many times. However, compared with the moon, Mars has an atmosphere (although relatively thin), and the environment is more complex. At the same time, the ground fire communication delay will reach about 20 minutes. Therefore, the whole landing process can only be judged and executed by the probe itself, and the ground has no time to do any disposal.
The whole landing process of tianwen-1 is about 9 minutes, during which the speed will be reduced from about 4.9 kilometers per second to 0.
The first step in this mission is to use the dense atmosphere of Mars.
When the aerodynamic deceleration, the detector has to face the high temperature process, as well as the attitude deviation caused by the aerodynamic. Once using its own aerodynamic shape and thermal protection structure to carry over the first stage of pneumatic deceleration, the speed of tianwen-1 detector will be reduced by about 90%.
Next, it needs to open its own parachute immediately until the speed drops to less than 100 meters per second, and then the variable thrust engine carried by the detector starts on time to enter the power descent phase.
When it reaches 100 meters away from the fire surface, the detector enters the hovering stage.
The probe may also move at an altitude of 100 meters to select a safer landing area for landing.
After independently determining the landing area, the lander will arrive at the surface of Mars under the protection of buffer mechanism and airbag.
Up to now, the three major fire detection tasks of human 2020 window are progressing smoothly. I wish them all a complete success and make new contributions to human deep space exploration!