Where did the Chang 'e IV probe land?

Chang 'e-4 detector is working overtime on a business trip. 65438+At 4: 55 a.m. on February 30th, scientific and technical personnel injected attitude adjustment and orbit change parameters into Chang 'e-4 probe at Beijing Aerospace Control Center. At 8: 54, the Chang 'e IV engine was successfully ignited, and the orbit change control was started. At 8: 56, the real-time telemetry data of the ground monitoring and control station monitored and judged that the Chang 'e-4 probe had successfully lowered its orbit from the orbit around the moon with an average height of about 100 km from the lunar surface, and entered the orbit around the moon with an altitude of about 15 km in the near moon and about 100 km in the far moon.

One of the purposes of this trip is to plan a soft landing in Aiken Basin on the back of the moon. Zou, deputy director of the National Space Science Center, said that in the past half century, humans have launched more than 100 lunar probes, but none of them have been able to land on the back of the moon: "The front and back of the moon are very different in material composition, morphological structure and rock age. Aiken basin is the largest and deepest basin among the solid objects in the whole solar system, and we can get the information of the deep materials in the moon. Due to the magnetic environment, low-frequency radio astronomical observation on the front of the moon is not effective. It is precisely because the magnetic environment on the back of the moon is very clean. The goal of low-frequency radio astronomy detection on the back of the moon should be said to be the dream of astronomers, which can fill the gap in the low-frequency observation section in the field of radio astronomy. "

For this journey, scientists and technicians also built a "bridge of magpies", not for the cowherd and weaver girl, but for the "Chang 'e". On May 2 1 this year, xichang satellite launch center successfully launched Xingque Bridge, the relay of the fourth mission of the lunar exploration project. Just like the name of "Queqiao", Sun Zezhou, chief designer of Chang 'e-4, said that relay stars provide relay measurement and control communication for Chang 'e-4 lunar probe. The "Queqiao" relay star was successfully launched and operated stably at L2 point, which should be said to be ready for a soft landing on the back of the moon.

Chang 'e IV set off on February 8, 65438+ and was successfully put into orbit around the moon on February 8, 65438+. 12. Since then, the Chang 'e-4 probe has made two orbit corrections around the moon, carried out four relay link tests with Queqiao relay star, and carried out on-orbit tests of navigation sensors such as laser ranging, three-dimensional imaging, microwave ranging and speed measurement, so that the probe can enter the scheduled landing area and measure the speed.

Sun Zezhou said that this exploration will also provide the possibility for the future lunar exploration project to continuously realize a deeper scientific exploration of the whole moon. He said: "This time we are expanding from the front of the moon to the back. Next, we will expand from the middle and high latitudes of the moon to the two levels of the moon to achieve access to the entire moon. "

Although there is no tradition of enjoying the moon in the New Year and there is no legend of "the Goddess Chang'e flying to the moon", we might as well look up at the moon on New Year's Eve tonight (65438+February 3 1). The real Chang 'e IV probe is "flying to the moon". According to the plan, it will make a soft landing on the back of the moon in June 20 19.

Although we ordinary people look up at the sky and can't really see it, there are devices in the sky that can clearly "see" us on the earth.

"The stars in the sky participate in the Beidou", and the Beidou satellite navigation system can tell you whether to walk eastward along the river.

Beidou is a global satellite navigation system independently built and operated by China, which is compatible with other satellite navigation systems in the world. This year, Beidou completed the launch of 10 arrow and 19 star, setting a new record for the construction of satellite navigation system in the world and the same type of space launch in China. On February 27th, 65438, Beidou-3 began to provide global services with a global positioning accuracy of10m. In the Asia-Pacific region, the positioning accuracy has also increased from 6 meters to 5 meters. Lin Baojun, chief designer of the Beidou-3 system satellite, said that the reason for the improvement in accuracy is that she has a stronger "heart".

Lin Baojun said: "We have broken through the seamless switching technology between the new hydrogen maser and the atomic clock. It can be said that the atomic clock is the' heart' of the navigation satellite, and this technology is also the core technology that determines the whole navigation accuracy. This breakthrough has improved the time-frequency accuracy of navigation system by an order of magnitude. In addition, our atomic clock can work continuously and seamlessly, which makes the Beidou system feel more stable, continuous and uninterrupted, and its performance will be better. "

"Beidou" does not lose its positioning, and "Hongyan" does not lose its connection. On February 29th, 65438+, the first satellite of Hongyan constellation was successfully launched and entered the scheduled orbit, and the China global low-orbit Internet satellite system was officially launched. The first experimental satellite launched this time will be tested and verified during its in-orbit period. According to the plan, the first phase of Hongyan constellation will consist of 60 satellites, which will mainly realize global mobile communication, Internet of Things, navigation enhancement, aviation surveillance and other functions. In the second phase, hundreds of satellites will be launched to form a global coverage capability.

Zhou Zhicheng, chief engineer of the Fifth Academy of Aerospace Science and Technology Group and academician of China Academy of Engineering, said: "Communication needs continuous coverage, and some places need multiple coverage, so such a system causes continuous coverage of this star, so the design of constellation, including relay mode and switching mode, is the difficulty of this."

Now all the networks we use need to set up base stations, but it is difficult to set up base stations in deserts, mountains, seas and other places, and mobile phones will also stop. With the "Hongyan" system, this will become history.

Looking back on China Aerospace in 20 18, Yang Yuguang, a researcher at the Second Academy of Aerospace Science and Technology in China and vice chairman of the Space Transportation Committee of the International Astronautical Federation, said: "The number of launches this year, including those by private companies, ranks first in the world for the first time. In the construction of space infrastructure in China, some remote sensing constellations are becoming more and more mature and applied. In space science, the successful launch of "Zhang Heng-1" has further strengthened communication with foreign countries in international cooperation, so as to realize more cooperation projects. In commercial aerospace, private aerospace companies have begun to enter the service field of orbital launch. This year,