But I didn't expect the plan to come true? On July 23rd, 2020, at 12: 00 Beijing time, China made its first Mars exploration mission? Tian Wen No.1? The probe was launched by the Long March 5 carrier rocket from Wenchang Space Launch Site on the northeast coast of Hainan Island. After the rocket flew for about 2 167 seconds, it successfully put the probe into the predetermined orbit, officially started the Mars exploration journey, and will arrive at Mars around 5438+0 on February 2026, which marks a new chapter in the field of deep space exploration in China.
Tian Wen-1 1: 1 Landing platform and rover Tian Wen-1 Mars probe consists of two parts, the landing patrol and the orbiter, with a total mass of about 5 tons. The landing patrol, including the entry module and the rover, is 1.85m high and weighs about 240 kg. The rover carries six payloads, namely:
Terrain camera, multi-spectral camera, underground detection radar, surface composition detector, surface magnetic field detector, meteorological measuring instrument, and in order to overcome the special environment on Mars, the rover also has the functions of environmental perception, obstacle recognition, local path planning, multi-wheel motion coordination control and so on. As for the life of the rover, it was originally designed as three Mars months, which is 92 days on our planet.
Under normal circumstances, the detection task needs to go through the following stages: first, crossing the detected star; Secondly, make the detector surround and detect the movement of the star; Then choose landing detection; Final patrol detection. But China chose the trinity mission requirement for this Mars exploration, that is, one-time realization? Surround, land, patrol? Behind these three goals, high technology and high risk are unprecedented.
? Tian Wen No.1? Landing point: The safety factors such as engineering angle, lighting conditions, TT&C communication conditions and landing point topography should be considered in the selection of detector landing point. At present, the landing site initially selected by scientists is between 20 and 30 latitudes in the northern hemisphere of Mars, which is a relatively flat place and has great scientific investigation value.
? Tian Wen No.1? Task: 1. Take photos of Mars and get a general idea of what Mars looks like;
2. Detect the substances and elements on Mars, and know what substances and elements are on the surface of Mars. Our scientists also installed a multispectral camera on the Mars orbiter and an elemental analyzer on the rover.
3. Explore the Martian environment and observe the Martian magnetic field, high-energy particles and medium-energy particles;
4. Detect the geological structure on the surface of Mars and observe whether there is ice water;
5. Detect the climate change on Mars, and understand the climate, sandstorm, temperature, wind, pressure and sound on the surface of Mars.
Why explore Mars? In the solar system, the fourth star from the inside out is Mars, which lies between the earth and the moon. Of the eight planets in the solar system, Mars is very similar to Earth:
First, one revolution of Mars is 24.66 hours, and day and night are only 40 minutes more than a day on Earth.
Second, the inclination of Mars' rotation is also close to that of the Earth, so there are four seasons on Mars: spring, summer, autumn and winter.
Third, there is also an atmosphere on Mars. So far, humans have been exploring Mars for nearly 60 years. Prior to this, * * * conducted 44 Mars exploration missions, of which only 8 landed successfully, with a success rate of only 18%. At present, there are only four countries or organizations that have actually explored Mars, namely the United States, Russia, the European Space Agency and India.
What are the difficulties in Mars exploration? First, the distance is too far.
The distance from the earth to the moon is only 380,000 kilometers, while the distance from Mars to the earth is 56 million kilometers and 400 million kilometers, and the nearest distance is equivalent to 1.47 times that from the earth to distance to the moon.
Second, the signal transmission is slow.
After the probe landed safely, the communication with the ground is very important, but the communication between any two points on the earth only takes 0. 13 seconds, and when it is closest to Mars, the speed of light also takes 180 seconds, so this long distance is a huge challenge for signal transmission.
Third, the technical requirements for track design are high.
The distance between fire and earth and its relative motion law require very high design of Mars exploration orbit, mainly because Mars and the earth are not on the same plane, and its orbit design difficulty can be imagined.
Fourth, it is difficult to land.
The atmosphere on Mars is very thin, about 1% of the Earth's, and the speed of the Mars probe reaches 20,000 km/h when it enters the Martian atmosphere, so that the probe will have intense friction with the atmosphere and cause intense fever. The time from entering the Martian atmosphere to landing is only 7 minutes, during which we have no communication with the probe.
Our detector needs to complete a series of operations such as pneumatic deceleration, parachute deceleration and reverse thrust. In these seven minutes. In addition, the resistance of the detector during landing is small, so it is too difficult to open the parachute in advance during high-speed landing. In the whole process, if there is a little mistake, it is very likely to crash into the atmosphere.
Fifth, the launch vehicle is stronger.
To go to Mars, we must not only get rid of the gravity of the earth, but also get rid of the gravity of the sun, so we need a more powerful launch vehicle.
About every 26 months, Mars will travel to the same side of the sun and the earth, that is? Mars rushes to the sun? So this time is especially suitable for launching probes from the earth to Mars. What do we call this period? Mars launch window? . The latest launch window is July and August in 2020.
In July 2020, multinational probes will explore Mars one after another.
At 5: 58 am Beijing time on July 20th, 2020, the first Mars probe in UAE? Hope? Launched from the Seed Island Space Center in Kagoshima Prefecture, Japan, it took about 200 days to reach Mars in February, 20021.
NASA plans to launch from Cape Canaveral Air Force Base in Florida? Perseverance? , will arrive on Mars in late February of 20021year. But at present, NASA has not announced? Perseverance? The specific launch time.