2020-07-02

It’s near! China’s first Mars exploration mission”Tianwen No. 1″ will be launched from July to August

By ddzyx

The coming of July, China’s first Mars exploration mission entered the launch window period.

At the launch ceremony of the fifth”Chinese Space Day” on April 24 this year, China officially released the name of the first Mars exploration mission. The name derives from the”Sky Question No. 1″ of Qu Yuan’s long poem”Sky Question”, which bears the tenacity and perseverance of the Chinese nation in pursuit of truth.

According to the plan,”Tianwen No. 1″ will be launched from July to August, and the three major tasks of”winding, landing, and patrol” will be completed at one time.

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Mars Rover appearance design configuration diagram. Xinhua News Agency published

Understanding the evolutionary history of the earth, predicting the future changing trends of the earth, and opening up new living spaces for human beings to find potential targets

Mars has As the hottest destination

With the development of aerospace technology, human interest and attempts in planetary exploration are increasing day by day. Among them, Mars is the world’s most popular planet”travel destination”. So far, there have been more than 40 Mars exploration activities worldwide.

Experts believe that searching for extraterrestrial life and studying the formation and evolution of Mars are the two major scientific themes of Mars exploration. China launched the Mars rover not only to study Mars and find the future home for mankind, but also to look at itself and explore the past and future of the earth.

Bao Weimin, academician of the Chinese Academy of Sciences and director of the Science and Technology Committee of the Aerospace Science and Technology Group, said that Mars is one of the planets in the solar system that is closer to the earth and has the most similar natural environment to the earth. Mars exploration not only helps to explore the existence and evolution process of Martian life, but also can understand the evolution history of the earth and predict the future change trend of the earth, and open up new living space for humans to find potential targets.

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2019 Nian 11 14, the completion of our first missions to Mars Lander hover obstacle avoidance test. Xinhua News Agency issued

If the mission is successful, China will become the first country in the world to explore Mars and complete the soft landing mission

China is confident to bend Road overtaking

According to the plan, China’s first Mars exploration mission will achieve three goals of”circling, landing, and patrolling” to Mars through a launch mission. In addition, the mission set five major scientific goals, mainly involving the study of space environment, morphological characteristics, surface structure and so on. To this end, the Mars rover is equipped with 13 types of payloads, including 7 types on the orbiter and 6 types on the lander. At that time, scientific issues of public concern will be detected.

Bao Weimin said that the Mars rover carries an atmospheric environment tester, which can obtain Mars temperature, wind and other information, and the public can intuitively understand the similarities and differences between Mars and the earth’s environment.

Explore Mars and complete the three-step detection scheme of”Falling Patrol” at one time, which is the first time in the world. If the”Tianwen-1″ mission is successful, China will become the first country in the world to explore Mars, that is, complete the soft landing mission, and become the second country to complete the Mars roaming after the United States.

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US” guts”rover . Xinhua News Agency issued

After the Mars Rover was launched, it will be “hurried” for 7 to 8 months

Expected February next year Arriving on Mars

Since Mars is far away from the earth, the detection of Mars needs to be selected when it is closer to the earth. According to experts, such an opportunity only occurs once every 26 months, and this July-August coincides with this time window.

After the launch time is determined, the Long March 5 remote rocket will launch the Mars probe to the ground fire transfer orbit Then, enter the ring fire elliptical orbit with the support of the ground measurement and control system, and run to the selected entry window. Subsequently, the probe will perform orbit reduction control and release the landing patrol assembly. After a successful soft landing of the landing patrol assembly, the rover will be separated from the landing platform to carry out regional patrol detection and related engineering practice activities. The surround will provide relay communication links for the rover and carry out surround scientific exploration.

This seemingly simple journey is actually full of challenges and dangers. Compared with the 380,000 kilometers traversed by the moon, and the distance of tens of millions of kilometers from Mars to Mars, the measurement and control communication of the aircraft is a huge test. After the Mars rover is launched, it will”hurry up” for 7 to 8 months. It is expected to reach Mars’ gravitational potential field in February next year, and then be captured by Mars before reaching Mars.

About 2030, China will implement missions such as Mars sampling and return, Jupiter exploration

Planet exploration program will go to depth

In order to ensure the launch of”Tianwen-1″, the Long March 5 Yao-4 rocket has also been fully prepared. In January of this year, the Long March No. 5 remote four rocket high-thrust hydrogen-oxygen engine completed the final verification before the final assembly, which marked that the performance of this engine reached the predetermined requirements and entered the stage of rocket assembly. On June 14th, Yuanwang No. 5 space ocean-going survey ship has also untied and set sail to a certain sea area in the Pacific Ocean to carry out maritime survey and control missions including Mars orbiting and landing patrol probes.

After completing the Mars exploration mission, China’s planetary exploration program will go deep. Bao Weimin said that around 2030, my country will implement missions such as Mars sampling and return, and Jupiter exploration, and is currently carrying out key technical research.

According to statistics, there have been more than 40 Mars exploration activities in the world, but the success rate is only 40%. The Mars exploration project has many difficulties. For the first time, China’s Mars exploration mission proposed a single launch to achieve the three goals of orbiting, landing, and inspection.

“Brake” in time to enter Mars orbit

During the launch window, the Sun, Earth and Mars will be in a straight line, of which the Earth and Mars The closest distance is only about 55 million kilometers. After a long-distance flight, how the probe was successfully captured by Mars’ gravitational field is one of the key points in the mission.

According to experts, during the long journey after”Tianwen No. 1″ was lifted off, the scientific and technological personnel will continuously correct the direction of the probe’s flight according to the specific conditions of the orbit. When you reach Mars, you must”brake” in time, and once the capture fails, the probe will pass by Mars and”slide” into the deep space farther. After the probe was captured by Mars’ gravitational field, it entered Mars’ circular orbit, and after many adjustments, it was possible to carry out surround detection.

Across the”terror 7 minutes” to achieve a soft landing

After reaching the orbit around Mars, the Mars rover will land on the surface of Mars. Although the landing process was only 7 minutes, this landing process called”Horror 7 Minutes” was the key point of the entire mission. Prior to this, no country in the world could complete the soft landing mission during the first exploration of Mars.

Why is landing difficult? Bao Weimin said that when landing, the Mars probe must reduce the speed from 20,000 kilometers to zero within 7 minutes, which requires a combination of aerodynamic shape, parachute, engine, multi-stage deceleration and landing recoil to implement Soft landing requires extremely high software and hardware requirements.

According to the introduction, the Mars probe has been flying at a high speed on the way to”fire”. Before landing, the speed needs to be reduced. Currently, there are two main modes of deceleration in the world. Based on the technical experience in the lunar exploration project, China gradually slowed down through four stages, and finally made the probe reach the surface of Mars smoothly.

The first stage is aerodynamic deceleration, and the speed is reduced from 4.8 kilometers per second to 460 meters per second by means of”emergency braking”; the parachute is opened in the second stage to reduce the speed to 95 meters per second ; The third stage is power deceleration, the detector’s reverse thrust engine ignition works to reduce the speed to 3.6 meters per second; the last 100 meters of the fourth stage is the hovering obstacle avoidance stage, the detector will hover in the air, right Observe the surface of Mars and make final preparations for the selected landing site.

“You can see if there are pits and large stones on the ground. If there are, we avoid them. This will ensure the safety of landing and will not roll over.” Bao Weimin said.

Release the rover,”combined work and rest” dry month

The lander will release the rover after the soft landing on the surface of Mars is successful, on the surface of Mars Carry out multiple missions such as patrol exploration and research on Martian landform features. It is worth mentioning that the rover will be equipped with a detection radar to detect a certain depth of Mars underground.

According to experts, the design life of the rover is 90 Martian days. Since a day on Mars is slightly longer than Earth (the rotation period of Mars is about 24 hours and 37 minutes), the rover will work 92 Earth days on Mars.

However, the rover is not”always sleeping.” In order to avoid the effects of extreme weather on Mars, the Chinese Mars rover will be set to sleep and wake up autonomously. Just like Chang’e-4 and”Yutu-2″, who are busy on the moon, the rover’s detection work also focuses on”combining work and rest.”

Bao Weimin said that due to the large delay of long-distance data transmission, the rover must have a high degree of autonomy. At the same time, the light intensity of Mars is small, and the Mars atmosphere reduces the sunlight, making the energy supply of the rover more difficult than the lunar rover. These factors make the Mars exploration mission more difficult and complicated.