With the continuous improvement of national economic development and the acceleration of national defense modernization, the demand for performance of communication satellites in China is becoming more and more urgent. The launch of the practice of satellite 20 represents the highest technology of China's satellite, and its research and development platform Dongfanghong5 satellite public platform will meet the gap of the future large-scale satellite platform spectrum, laying a solid foundation for China's high-throughput communication satellite development in the next 20 years
Recently, China's practice satellite No.20 was successfully launched by the Long March-5 remote three carrier rocket at China's Wenchang space launch site. This satellite is the first test star of China's new generation of large-scale geostationary-orbit satellite platform, the Dongfanghong-5 satellite utility platform (hereinafter referred to as Dong5 platform), which is of great significance to enhance the maturity of new technologies, promote the application of new technologies and further promote the development of space technology in China.
The first task of the satellite is to verify the technical stability of the East Fifth Platform and carry more than 10 international leading technical verification loads, which is the most important one in China at present. Academician zhou zhicheng, chief engineer of the fifth institute of space science and technology group, commander-in-chief of satellite 20 of practice and commander-in-chief of public platform of east red 5 satellite, told the economic daily that \"naming a satellite after'practice' is the best interpretation of the star's exploration significance.\"
Communication satellite, which aims to realize information transmission, is the neural network of information society. It has the advantages of long communication distance, large coverage area, high channel quality and large communication capacity, and is widely used in international and domestic or regional communications, maritime communications, television broadcasting and other fields.
\"Satellite development, platform first \". The application performance of satellites is often realized by loading loads with different functions on a common platform. At present, many countries in the world adopt the design method of satellite common platform, the platform can carry different payloads with only a small amount of adaptive modification, so as to shorten the satellite development cycle, save the development funds and improve the satellite reliability.
For a long time, China has formed the Dongfanghong 3, Dongfanghong 4 as the representative of the Eastern Red series satellite public platform and type-spectrum products. With the continuous improvement of national economic development and the acceleration of national defense modernization, the demand of China's communication satellites for performance leapfrogging is becoming more and more urgent. \"The original intention of the development of the East Fifth Platform is that China needs high-throughput communication satellites. Academician Zhou Zhicheng said. With the characteristics of \"high bearing, high power, high heat consumption and high control precision \", the East Fifth platform has reached the international leading level, which will fill the blank of the spectrum of the large-scale satellite platform of the Dongfanghong series, and can meet the demand of high-throughput communication satellites in China in the past 20 years.
According to Pei Shengwei, deputy chief designer of the Space Science and Technology Group's Fifth Institute, in order to give full play to the effectiveness of the satellite's in-orbit verification and aim at the future development needs of the spacecraft, the research and development team carried out a number of rounds of selection from the numerous carrying test projects collected throughout the country.
The successful launch of the practice of satellite 20 condensed the great wisdom and effort of researchers, the numerous \"cool techs\" blessing also let it have a real kung fu.
Many have compared the solar wing to a satellite's \"wing \", but its role is not to fly, but to provide energy for the satellite. The \"wing\" of the satellite is the largest in size, the longest wingspan, and the most complex spread of the solar wing in China so far, and its wings are 10 meters wider than the wingspan of the Boeing 737. The large increase in solar wing area can bring continuous super-current supply, so that the practice 20 satellite has always had a lot of physical strength, to provide more radio and television, mobile communications and other services.
The giant solar wing of the 20th satellite cannot wave up and down like a wing, but it can rotate at low speed, ensuring that it is always oriented towards the sun, thus maximizing solar energy. The solar wing is driven by a \"small joint \"- the solar wing driving mechanism, although small, but a heat and cold resistance to the impact of the\" Hercules \", it can easily withstand the impact of the giant solar wing impact load, driving more than 100 jin of mass rotation is not in the next word.
The solar wing of satellite 20 can also provide super current. How can these currents be allowed to flow, either large or small, obediently, into every corner of the satellite's device to maintain its healthy operation? To this end, the researchers equipped the satellite with a \"big heart \"- the most powerful power controller in the country. Compared with the first-generation power controller, when the power increases by more than three times and the power density increases by only 40%, the domestic power controller can run and lead the way.
With the increase of the Internet service of satellite, the demand for large-capacity communication satellite is more and more urgent. The high-flux communication load developed by the Fifth Academy of Aerospace Science and Technology Group(CAS)carried by satellite 20 covers Q\/V band load, broadband flexible transponder, etc. ``The main means of increasing satellite communication capacity is to increase the bandwidth of the available frequency band, which is the most crowded highway on all space highways if the stationary orbit is compared to a highway in space. However, the use of the Q\/V band is equivalent to expanding the highway by four to five times, which will greatly relieve the current international competition against the frequency of the stationary orbit. ``said Li Feng, chief designer of No. 20 satellite of the Fifth Academy of Aerospace Science and Technology Group.
From a set of numbers you can see the \"crossing\" of East Five. Compared with the former telecommunications satellite family's active \"main products\" east three, east four, the weight of east five increased from ton to 8 tons, in orbit life from 15 years to 16 years, the whole star power from 10 kilowatts to 28 kilowatts. It is not difficult to see that the East five platform is larger, higher and stronger, with the characteristics of \"high load bearing, high power, high heat consumption and high control precision \", reaching the international leading level.
Through modular design and digital development mode, the East Fifth Platform can greatly shorten the development cycle and improve the production efficiency. At the same time, the single-machine localization rate of the East five platform reaches 100%, which will be able to drive the development of China's space equipment.
As a large-scale satellite public platform in geosynchronous orbit in china, the east five platform can be widely used in many fields, such as high-orbit communication, microwave remote sensing, optical remote sensing, space science exploration, scientific experiment, in-orbit service and so on.
Therefore, the successful launch of satellite No.20 marks a step forward in the maturity of the East Fifth platform and lays a solid foundation for the comprehensive popularization and application of the East Fifth platform. Especially at present, with the development of commercial satellite live broadcast, emergency communication, mobile communication, Internet of things and the steady development of conventional fixed satellite communication, the satellite communication industry has rich demand and broad market, and the new business needs represented by broadband communication satellite are becoming more and more urgent.
The industry predicts that by 2022, large-capacity (high-throughput) satellites will account for 50% of the global total satellite bandwidth; after 2022, China's broadband satellite capacity demand will also reach more than 1TB. Facing the broad demand and serving the national \"\"and \"broadband China\" strategy, our country will rely on the East five platform to develop several communication satellites with 100GB to 1TB capacity to cover the countries along the \"Belt and Road\" and the surrounding areas. (Jiang Tianjiao)