Deep Space TT&C Series Equipment: Signal "Amplifier" 400 million kilometers away.

Compared with the 380 thousand kilometers covered by landing on the moon, it takes tens of millions of kilometers for the earth to reach Mars. It will take about seven months for the Tianwen 1 probe to reach Mars. After that, the lander made a soft landing on the surface of Mars, made patrol detection near the landing area, and carried out relay and remote sensing detection around the orbiter for two years.

In order to receive clear and accurate signals from tens of millions of kilometers away, the measurement and control system plays an important role.

"During the whole mission, the measurement and control system is mainly responsible for completing the tasks of orbit determination, state monitoring and flight control in each flight stage of the detector, and controlling the operation of the landing patrol during the surface exploration stage of Mars." Experts from China Electric Power Department said that compared with low earth orbit, the longest working distance of this mission reached 400 million kilometers, which put forward newer, higher and stricter requirements for the measurement and control system.

China Electric Power Branch has developed the accumulated experience of TT&C communication in previous space launches, and equipped a series of TT&C equipment to escort the Mars probe to determine its orbit in the vast "Xinghai".

Jiamusi deep space measurement and control station, the "all-round hand" sent back by accurate signal capture. Jiamusi deep space TT&C station, as the main test equipment of TT&C system, is the first deep space TT&C station with super-large aperture antenna in China, which can provide TT&C communication support for the second and third phases of lunar exploration, Mars exploration and subsequent deep space exploration missions.

As the overall unit of Jiamusi Deep Space TT&C Station, China Electric Power Department has carried out adaptive transformation to improve the performance of Jiamusi Deep Space TT&C Station. "In this Mars exploration mission, the farthest distance reached 65.438+0.9 billion kilometers, which means that the downlink signal sent by the Mars probe is extremely weak when it reaches the Earth. How to capture accurate signals is extremely important for Jiamusi deep space measurement and control station. " Du Dan, chief designer of China Diantianao, introduced that Jiamusi Deep Space TT&C Station is equipped with a cryogenic superconducting receiver and a 66-meter large-aperture antenna, just like a high-sensitivity "stethoscope", which is responsible for finding and capturing detector signals in outer space noise and demodulating various parameters such as detector power supply, temperature, instrument working state and scientific test data. When the probe arrives at Mars, Jiamusi TT&C station equipped with 10kw CW ultra-high power amplifier is like a "remote controller" with a very long working distance, which sends ground instructions to the satellite to realize the orbit change of the probe, the opening of solar panels, the soft landing of the landing patrol, the control of test instruments, etc. In addition, Jiamusi Deep Space TT&C station can also play the role of "data highway" to realize the transmission, reception and demodulation of images and other data.

Asia's largest single-hole all-mobile antenna, high quality and high reliability "transceiver". "As we all know, the farthest distance of a fire is about 1000 times that of the earth to distance to the moon. The attenuation of the transmitted signal is proportional to the square of the distance. Signals with the same transmission power will reach the earth weakly. Increasing the aperture of the ground receiving antenna, that is, the receiving area, is the basic way to improve the signal-to-noise ratio. " According to 39 technical experts from China Electric Power Network News, in order to receive the weak signal data 400 million kilometers away from China's first Mars exploration project, the Ministry of Electric Power of China undertook to build a 70-meter antenna (GRAS-4) high-performance receiving system, which will become the largest single-aperture full-active antenna in Asia after completion, which can greatly improve the downlink data receiving ability of deep space exploration in China, reduce system noise and improve anti-jamming ability. It has the functions of stably receiving weak artificial data signals and sensing extremely weak electromagnetic waves radiated by natural objects in the universe, which provides a solid foundation for completing China's first Mars exploration engineering mission and subsequent deep space exploration missions.

In addition, China Netcom has also developed and installed a 35-meter deep space exploration antenna array, which is also the first deep space exploration antenna array in China. It consists of several 35-meter-beam waveguide antennas, which can establish a high-quality and reliable RF channel between the ground and the interstellar probe, complete the data receiving task, serve China's lunar exploration and Mars exploration projects, and help China enter the world's advanced ranks in the field of deep space exploration.

High-power power amplifier equipment is the "remote control" of the running route of "Tianwen No.1". In order to adjust the attitude and orbit of Tianwen-1, it is necessary to transmit the signal from the large-aperture antenna to the satellite. In this process, the power needs to be amplified by a high-power amplifier. Shan Xiuxu, general manager and senior engineer of the Aerospace Division of No.27 Electric Defense Institute, said that the TT&C system in deep space has extremely high requirements for high-power amplifiers, especially when the extreme power output of each frequency band is unprecedented in China. After years of hard work, the team members of 27 projects have successfully developed a series of high-power amplifiers and successfully carried out many specific tasks such as Chang 'e II, Chang 'e III and Chang 'e IV.

According to the specific characteristics of this Mars exploration mission, 27 teams have successfully developed a prototype of ultra-high power and high power amplifier in a certain frequency band, which has realized the stable output capability of ultra-high power continuous wave power in this frequency band for the first time in the field of deep space measurement and control, laying a solid technical foundation for the follow-up work.