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The escort is just for “Five” to go home
On the voyage home to Chang’e 5, the ship Yuanwang 3 of China’s Marine Satellite Monitoring and Control Department escorted Chang’e 5 into the depths of the Indian Ocean.
For this mission, the Yuanwang 3 ship is the only marine monitoring and control force. During the mission, the spacecraft must complete telemetry, external measurement and optical measurement tasks near the “black barrier” of the initial re-entry into the atmosphere from which it returns. It is understood that the return device can only be captured and tracked by the ship’s monopulse radar and the photoelectric theodolite on the “black barrier”. It seems like it only takes 3 minutes, but the difficulty of measurement and control is beyond imagination.
In response to the complex measurement and control process, Wang Erjian, an engineer with the General Technology Department of the China Marine Satellite Measurement and Control Department, said: “Optical tracking equipment is like looking for meteorites flying at high speed in the sky. through a telescope with the naked eye. The target is flying very fast and difficult to capture. The pulse radar search beam is relatively narrow and there is no response signal from heaven and earth on the return device. The radar needs to use the reflection signal from the plasma layer to track. The surface of the plasma layer is very uneven and the reflection signal fluctuates greatly. All of this is for target search and capture and stable tracking. Here comes a great challenge. “
Zhang Wei, the chief dispatcher of the Yuanwang 3 ship, said that in order to efficiently and successfully complete the marine measurement and control task, the Yuanwang 3 ship entered the mission state in advance and was fully prepared. On the mission, the COSCO Yuanwang 3 unified S-band measurement and control team issued an attitude adjustment command within a short period of 100 seconds before the returning one entered the “black barrier”; the photoelectric theodolite took over the optical tracking task of the returner and intuitively provided the return flight image information of the aircraft; the monopulse radar is the main responsible for the tasks of external measurement of the area of the “black barrier” of the returner, providing reliable measurement data for the entire area, and is the “first rod” for the returnee to enter the atmosphere already the entire measurement and control support system. Important link.
In the search and rescue mission on the landing field, there is another satellite that plays an important role: this is the first satellite of China’s second-generation data relay system, Tianlian-2 01. The satellite established a link of information transmission between the search and rescue air unit communications helicopter and the Beijing Aerospace Flight Control Center, and carried out the real-time transmission of commercial data such as images, voice and dispatch, laying a solid foundation for the successful search and rescue mission.
The Tianlian-2 01 satellite was launched in March 2019 and can provide excellent data relay, measurement and control and transmission services for users of manned spacecraft, satellites and launch vehicles. Before this mission, the Beijing Space Information Transmission Center, in accordance with the Landing Field Command arrangements, manually enter the theoretical landing coordinates of Chang’e 5 to set the relevant state, cooperate with the exercises of the landing field mission and upload the mission operations plan in advance. Set the initial pointing latitude and longitude and other related parameters.
“Before search and rescue personnel board the aircraft, personnel in our communications operation position have activated helicopter dispatch measures in accordance with the dispatch command password. During the search and rescue mission, personnel must monitor the maintenance of various information transmission links and carefully observe the optical crane. The situation of transmission of the image of the cabin ”. According to Qin Mingchen, the mission general engineer, the staff should be careful enough to determine whether the antenna orientation should be adjusted in time based on the real-time position of the helicopter to ensure smooth transmission of search information. and rescue.
“Twenty-three days ago, we also provided space-based measurement and control services for the Long March 5 Yaowu carrier rocket through the Skylink satellite in this room, and successfully shipped Chang’e 5. Today, we have received it. successfully”. Gao Quan, the dispatcher for the second mission, said proudly.
(Feng Hua, Yu Jianbin, Gao Chao, Qi Chuang, Wang Ran)
