This article is from WeChat official account:Qubits (ID: QbitAI)< span class = "text-remarks">, author: Guhao Nan, the original title: “the US Mars rover lost contact seven minutes of HD video footage back to the” head map from: NASA

The sky is full of yellow sand, the smoke is billowing, and the American Mars rover “Perseverance” returns a terrifying 7-minute video:

What is “horror” 7 minutes?

This is the last and most dangerous stage of Mars landing. During this period, the spacecraft completely loses any means of communication and can only rely on autonomous control to complete the landing.

In several previous NASA missions to Mars, only images or short videos with limited resolution were obtained.

The video returned by Perseverance is the first time that humans have recorded a high-definition first-person view of the landing of a Mars rover, with a total amount of up to 30GB.

The content released by NASA also allows us to more intuitively understand everything that “Tianwen No.1” will experience three months later.

You are a mature rover…

A mature Mars rover must learn to complete the landing by itself.

From entering the Martian atmosphere until 7 minutes after the completion of landing, Perseverance was unable to communicate with the outside world.

In the 7-minute “black barrier”, Perseverance had to reduce its speed from nearly 7000m/s to zero through autonomous control, and it had to steadily land on the surface of Mars..

In the video released by NASA, the beginning is the picture of opening the parachute:

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(The parachute pattern hides the mystery, the article will be revealed at the end!)

Immediately afterwards, the heat shield was ejected. In the video, you can see that a spring used to eject the shield has broken, but this did not affect the whole process:

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After that, the camera captured the red and desolate surface of Mars.

During this process, the lander keeps slowing down, and the camera keeps taking pictures of the surface conditions, and sends the data back to the rover processor to select a specific and more appropriate landing point.

In these seven minutes, where is the horror?

Perseverance was done in one go, but before this mission, NASA had bluntly stated that the success rate of the “7 Minutes of Terror” mission was only 40%.

Where is the difficulty?

“7 Minutes of Terror”, counted from the time the rover left the spacecraft and entered the Martian atmosphere, until it completed the landing action and stopped firmly on the surface of Mars.

(The animated picture is NASA animation presentation, not live video)

Any vehicle that logs on to Mars must face this difficulty.

Compared to the earth, the thin atmosphere of Mars makes it more difficult to decelerate and control the device’s attitude.

In the process of descent, the ultra-high temperature surface created by the friction between the insulation layer and the atmosphere will form a layer of plasma.

The plasma group will shield the signal, which makes the control center unable to directly operate the spacecraft and can only rely on automatic.

It takes three months to scan and map the surface of Mars, including recording the atmosphere, magnetic field, trade wind, temperature difference and other data of the fire table.

All this will accumulate important data for the follow-up mission of Tianwen-1 and all future Mars exploration missions in China.

For the United States, the exploration of Mars was carried out earlier, and these roads have been traversed again. Therefore, Perseverance chose to “pump one end” directly on the surface of Mars.

At present, Tianwen-1 has entered orbit on February 10, and it is planned to implement the Mars rover landing mission around May.

Different from Perseverance’s direct “air crane” landing, Tianwen-1 will use a powered descent method for landing, that is, rocket reverse hovering and landing technology.

In other words, the reverse thrust rocket will continue to work until the lander lands on the surface of Mars.

34 degrees 11 minutes 58 seconds north latitude 118 degrees 10 minutes 31 seconds west longitude.

These are the coordinates of the Jet Propulsion Laboratory in Pasadena, USA.

This is the romance of science and engineering~

NASA “7 Minutes of Horror” video:



This article is from WeChat official account:Qubits (ID: QbitAI)< span class = "text-remarks">, author: focus on the forefront of technology