This article is from WeChat official account:Guokr (ID: Guokr42)< span class = "text-remarks">, author: space craft, the original title: “death seven minutes! Perseverance will land on Mars in the early hours of tomorrow”, title picture from: Visual China
The first close-up photo of Mars sent back by Tianwen-1 | CNSA
Mars, the red planet in the solar system, has recently been full of guests.
First, on February 9, the UAE’s Nozomi probe arrived on Mars and braked into orbit.
One day later, China’s Tianwen No. 1 was also successfully parked in the ring fire orbit. Although carrying a lander and a patrol, Tianwen-1 needs to survey Mars for about three months before choosing an opportunity to land on Mars.
And early tomorrow morning Beijing time, the US Perseverance will also arrive on Mars. Unlike Hope and Tianwen-1, Perseverance will not orbit Mars, but will directly land.
So, in 2021, the first landing on Mars will be staged by the Perseverance rover.
The Perseverance will go straight to Mars| NASA
After reaching Mars, the rover will communicate with the Earth for the last time to ensure that all systems are working properly. Subsequently, the modules that provide communication and power are separated, and the rover will go straight to the Martian atmosphere.
During this process, the attitude control jet engine will start to work to strictly control the angle and direction of the landing track. If the angle is too large, the heat generated by breaking into the atmosphere will exceed the limit of the insulation layer, and the lander will be burned; if the angle is too small, the lander will slide into deep space like a water drift and miss this only landing on Mars. Opportunity.
After the angle adjustment is completed, the protected rover plunged directly into the Martian atmosphere at a speed of more than 5000 m/s at a distance of about 100 kilometers above Mars.
The “Seven Minutes of Death” has officially begun!
The Perseverance, which is under tight protection, bursts into the Martian atmosphere | NASA
Slow down in layers
At a height of 45 kilometers from the surface of Mars, the heat of the rover’s thermal insulation reaches its peak, and the temperature will reach an astonishing 2100°C.
Under the huge sacrifice of internal high-tech protection and external insulation, the temperature of the rover is only about 10°C.
During this process, the atmosphere also helped the lander achieve a deceleration effect, reducing its speed to about 450 meters per second.
Perseverance opens the parachute | NASA
At an altitude of 11 kilometers from the surface of Mars, the lander will open a huge parachute with a diameter of 15 meters and a height of 50 meters. It is the largest parachute that humans have ever used on other planets.
After the parachute was opened for 75 seconds, the speed of the rover finally dropped to only 90 meters per second.
This is the limit for the heat-insulating outsole and parachute to work hard, but it is still fast enough to make the rover fall to pieces.
Not slow enough, it needs to slow down further.
Comparison of the dimensions of the three-generation Mars rover, the size of Perseverance is the same as the Curiosity on the far right in the picture | NASA
This last step slows down, and different rover can be said to have their own magical powers.
NASA’s first-generation Sojourner rover, which was only the size of a microwave oven, mainly used verification technology, and landed on the surface of Mars carried by the Pathfinder lander.
The Mars Rover Valor and Opportunity are over 200 kilograms in size, and the instruments they carry are relatively complicated. They use rocket reverse thrust and airbag bounce to complete the final deceleration.
And Perseverance is about the same size as Curiosity/JPL
The structure and power system of the Mars rover are gradually deployed, and the bottom sensor reports the real-time status to the aerial crane through the “umbilical cord”. Once the rover is sensed to touch the ground stably, the nylon rope and cable will be cut off in an instant. The aerial crane that completes the mission will use up all its energy, fly as far as it can, and eventually crash into the distance.
The whole process is equivalent to throwing a family car from the Burj Khalifa, starting the aerial crane midway, hovering to avoid obstacles and placing the car steadily on the ground without triggering the car’s anti-theft alarm system.
It’s hard to imagine.
The Perseverance aerial crane technology will be further upgraded | NASA
Not only that, because Perseverance’s scheduled landing area is in the delta area of the ancient river, the terrain is complex, and its aerial crane is also integrated with a high degree of intelligence, which can autonomously avoid risk areas, choose the optimal path, and place the rover To the most ideal location.
If Curiosity’s aerial crane can safely “throw” it onto the ground from Burj Khalifa, then Perseverance’s aerial crane can accurately “throw” it into a parking space.
The scheduled registration of the Perseverance RoverLand Point | NASA/ESA/Justin Cowart
If all goes well, at 4:55 tomorrow morning Beijing time, Perseverance will land near an obvious delta alluvial fan in the Jezero crater on Mars.
Billions of years ago, there was once a country of Zee. If life has ever appeared on Mars, there should be the most hopeful relics of ancient life. This is also one of the primary goals of the Perseverance rover to the red planet.
I wish Perseverance a successful landing on Mars!
This article is from WeChat official account:Guokr (ID: Guokr42)< span class = "text-remarks">, author: space craft