Scan the QR code with wechat < / P > < p > to share with friends and circle of friends < / P > < p > on May 14, < a target = "_ blank" href=" https://news.163.com/news/search?keyword=%E5%9B%BD%E5%AE%B6%E8%88%AA%E5%A4%A9%E5%B1%80 "> China's first Mars exploration mission < a target ="_ blank" href=" https://news.163.com/news/search?keyword=%E5%A4%A9%E9%97%AE%E4%B8%80%E5%8F%B7 "> tianwen-1 < / a > < a target ="_ blank" href=" https://news.163.com/news/search?keyword=%E6%8E%A2%E6%B5%8B%E5%99%A8 "> since the launch of the detector on July 23, 2020, all systems have been working normally. On February 10, 2021, tianwen-1 probe entered the orbit of annular fire, carried out scientific exploration and obtained a lot of scientific data. According to the current flight situation, tianwen-1 is planned to be launched from the early morning of May 15 to May 19, Beijing time_ blank" href=" https://news.163.com/news/search?keyword=%E6%8B%A9%E6%9C%BA "> choose the right time < / a > < a target ="_ blank" href=" https://news.163.com/news/search?keyword=%E7%9D%80%E9%99%86 "> landing on the Martian Utopian plain Related reading: < / b > < / P > < p > < b > tianwen-1 will choose its plane to land. Why does it need "ink" for three months At 19:52 on February 10, 2021, after six and a half months of flight, China's first independently launched Mars probe tianwen-1 successfully completed the "braking" deceleration (near fire braking) and entered the orbit around Mars, becoming China's first man-made Mars satellite A few days later, NASA willpower, launched from the same Mars window, also arrived on February 18, 2021. Both Rovers carry Mars rovers < p > (left) the 1:1 model of China's zhurong Mars rover | people's pictorial (right) NASA's willpower Mars rover and the CG model of the wit UAV | NASA < / P > < p > the difference is that willpower Mars rover landed directly on the day it arrived on Mars, while tianwen-1 plans to fly around Mars for more than three months, and will select a plane to land in the near future and separate the Mars Rover "zhurong"

Why did tianwen-1 wait three more months

There are differences in composition and division of labor < / strong > < / P > < p > tianwen-1 is composed of a orbiter, a landing platform and a Mars rover. After the orbiter enters the orbit around Mars, it can fly with the landing platform and the Mars rover all the time (the two are collectively called landing patrol assemblies, which are stuffed in the pneumatic cover), and has enough time to choose the appropriate landing time However, NASA's willpower has no orbiter. It uses a cruise stage to fly to Mars with a pneumatic cover (with a Mars rover in it), and it is not designed to enter the orbit around Mars. When the cruise plane flies near Mars, it can't wait for its ramless aerodynamic cover to plunge into the Martian atmosphere immediately NASA perseverance module NASA < / P > < p > it doesn't mean that perseverance doesn't need a orbiter, but there are several Mars orbiters NASA is working on, which can not only complete all kinds of Mars in orbit scientific exploration, but also provide enough communication relay for Mars rover, so it doesn't matter if you don't bring them this time At present, NASA is working on the Mars probe | NASA < / P > < p > and tianwen-1 is China's first autonomous Mars mission. There is no "take over" on Mars. Of course, we have to bring more equipment on our own. Self sufficiency, self-reliance CNSA < / P > < p > < strong style = "box sizing: inherit; font-style: normal;"> It takes time to investigate the terrain < / strong > < / P > < p > after entering orbit, tianwen-1 is really busy. Believe me, it's all for the safety of zhurong. Sharpening the knife doesn't miss the firewood cutter < p > first, he spent half a month adjusting his orbit many times to make his "observation" of Mars closer and better; Then, we carefully investigated the terrain of Mars, took high-definition photos, and explored the terrain of the landing area for the Mars rover On February 10-24, 2021, tianwen-1 completed three times of near fire braking (de orbiting) and one time of far fire plane maneuver (rollover), and successfully entered the Mars docking orbit with a cycle of two Mars days | CNSA < / P > < p > at this time, you may have to ask, isn't that right? Why other Firestar orbiters have taken a lot of photos, Does tianwen-1 have to spend time photographing itself to explore the terrain and confirm the landing area? This is because photos are different from photos < p > tianwen-1 "scan" Mars map | CCTV < / P > < p > in the case of the same shooting distance, the camera with low resolution of the probe can shoot a large area (or a wider picture) at a time, while the camera with high resolution can only shoot a small area. Resolution and coverage are the eternal contradiction of detector photography < p > taking NASA's Mars Reconnaissance Orbiter (MRO) as an example, MRO has two cameras: at an altitude of 300 km, the medium resolution camera CTX can take a 6 m / pixel image of Mars, and each image can cover a 30 km wide area on the surface of Mars; The high-resolution camera HiRISE can take high-definition photos as high as 0.5 m / pixel, and each photo can only take an area of 6 km wide As a result, Rao Shi, a model worker of MRO who has been working since 2006 and has been taking photos of Mars for 15 years now, only the medium resolution CTX images almost cover the whole world of Mars, while the high-resolution HiRISE images only cover a few scattered places. In a word, for Mars, the coverage of the existing meter level high-resolution images is still too small, which can only give priority to the areas that we want to focus on NASA has spent a long time accumulating high-resolution image data for the candidate landing area before willpower's landing (see: NASA willpower successfully landed on Mars! Where will it look for Martian life? https://www.kepuchina.cn/more/202102/t20210223_ 2969108. Shtml), that is to say, perseverance had a high-definition map of the landing area in hand before it set out < p > the HiRISE image in the area of Jezero crater in the landing area of willpower is covered (blue). Each image is 6km wide, and the white circle is the landing ellipse of willpower | < / P > < p > and what about tianwen-1? Tianwen-1 plans to search for a landing area in the Martian Utopian plain, but the coverage of HiRISE image is like this when a piece of land is picked up in such a large plain. If we want to go to the high resolution Mars that we have ?
2023-03-22 10:04:33