Speaking of the "heavenly palace classroom", you will not be unfamiliar with it - the slow "blooming" of flower origami in the water film, the magical scene of effervescent tablets put into blue water balloons, the interaction between heaven and earth in which fantastic ideas collide... How does this long-time "video call" between heaven and earth achieve? "We have built an efficient and stable communication transmission 'Heaven Road' between heaven and earth!" Chen Jianmin, a measurement and control expert of CETC, introduced that in the measurement and control station and relay satellite system, CETC has woven a full coverage aerospace measurement and control communication network from different dimensions, which is networked and operated with the relay satellite erected in space and 36000 kilometers away from the earth. The images and sounds of "Tiangong classroom" were collected by the measurement and control station and "sent" to our eyes. Audio-visual transmission is only an "appetizer". The magic power of aerospace measurement and control system is great! For example, the Mars probe tianwen-1, which has successfully set fire and continued its exploration activities. It is hundreds of millions of kilometers away from the earth, but it can accurately receive ground instructions and successfully complete each action. This "order" and "line" through heaven and earth depend on the aerospace measurement and control system, and the whole process is like "making a phone call". Then take Shenzhou 13 manned spacecraft as an example. The ground measurement and control station sends out the "inquiry" of "where are you" through radio waves. Shenzhou 13 receives this signal through the receiver and feeds back to the ground measurement and control station in the form of radio waves through the transponder. Through countless such questions and answers, technicians can accurately know the height, specific position and flight trajectory of Shenzhou 13, and guide it to complete a series of actions such as flight, orbit change and docking. At present, the exploration of the moon and Mars is the highlight of international deep space exploration. In order to better understand the "star moon story", in addition to "visiting", it is also important to sit on "remote sensing". As the only link between the earth and the deep space probe, the deep space probe and control system in the measurement and control family is showing its hand. In order to complete the first Mars exploration mission, China completed the construction of four 35 meter aperture antenna array deep space measurement and control systems in Kashgar, Xinjiang in 2020, and built the largest 70 meter aperture fully movable antenna in Asia. This gives us the ability to stably receive weak man-made data signals and perceive extremely weak electromagnetic waves radiated by natural celestial bodies in the universe, realizes the remote sensing data reception of cosmic deep space detector and the scientific research of radio astronomical observation, and greatly contributes to the reception of scientific data of "tianwen-1". You know, in the process of executing the task, each measurement and control station does not act alone. They cooperate closely to ensure that the aircraft is always within the visual range, and capture the position and state of the aircraft in a continuous way without dead angle. It can be said that this is a superb technical relay, which needs close coordination. As the overall research and development unit of Aerospace TT & C communication system, CETC has led the development of a series of deep space TT & C stations in Kashgar, Jiamusi and South America. When carrying out space missions, technical experts have to go home and abroad, stay outside the TT & C station for a long time, maintain and upgrade the equipment, and withstand all kinds of tests such as Gobi, waves and foreign countries day and night. They can't put down their hanging heart until they receive the news of successful launch. Looking at the Star River in the distance, my heart is tied to the sky. It is with these space "watchers" that we can continuously uncover the mystery of the universe. (Xinhua News Agency)