Space debris is very dangerous to the security of on-the-orbit spacecrafts, and it is increasing in number at high speed with the expansion of human space exploration. Space debris has become a serious space pollutant...Space debris is very dangerous to the security of on-the-orbit spacecrafts, and it is increasing in number at high speed with the expansion of human space exploration. Space debris has become a serious space pollutant noticed by many astronomers. The increase of space dust sources and the development of research on space dust urgently need space dust data sharing and exchanging. It is necessary for us to establish the Space Dust Database to realize the sharing and canonical management of the data. The Space Dust Database (SDD) management system, based on the 3-layer B/S computer mode, was designed and implemented in this paper. The system’s features include significantly improved runtime efficiency, good scalability and maintainability. The Space Dust Database can provide some scientific bases for the study of the chemical constituents, mineral composition, origin and sources of space dust, but also provide excellent data services and decision-making support for the protection of space and model construction of space dust.展开更多
A spacecraft＇s separation parameters directly affect its flying trace. If the parameters exceed their limits, it will be difficult to adjust the flying attitude of the spacecraft, and the spacescraft may go off-track...A spacecraft＇s separation parameters directly affect its flying trace. If the parameters exceed their limits, it will be difficult to adjust the flying attitude of the spacecraft, and the spacescraft may go off-track or crash. In this paper, we present a composite optimization method, which combines angular velocities with external moments for separation parameters of large-eccentricity pico-satellites. By changing the positions of elastic launch devices, the method effectively controls the popping process under the condition of less change in the separation mechanism. Finally, the reasons for deviation of angular velocities and unreliable optimization results are presented and analyzed. This optimization method is proved through a ground test which offsets the gravity. Simulation and test results show that the optimization method can effectively optimize the separation parameters of large-eccentricity pico-satellites. The proposed method adapts particularly to the fixed and non-stable status elastic parameters, the distribution of all kinds of elastic devices, and large-eccentricity spacecrafts for which attitude corrections are difficult. It is gen- erally applicable and easy to operate in practical applications.展开更多
On May 4, 2018, as the chief engineer, Prof. SUN Weigang, signed his name on the Review Report, the Solar Ha Imaging Spectrometer spacecraft was finally approved by the Chinese Space Agency. This is the second spacecr...On May 4, 2018, as the chief engineer, Prof. SUN Weigang, signed his name on the Review Report, the Solar Ha Imaging Spectrometer spacecraft was finally approved by the Chinese Space Agency. This is the second spacecraft designated for solar observations in China, coming on the heels of the Advanced Space-born Solar Observatory （ASO-S）, which was approved by the Chinese Academy of Sciences on December 29, 2017. The approval of the two space missions for solar observations marks a milestone for the Chinese solar physics to glide into the space age.展开更多
The Space Power Satellite(SPS) would be a huge spacecraft capturing the power of solar radiation in space and to supply electric power to the electric grid on the ground. The SPS concept was proposed by Dr. Peter Glas...The Space Power Satellite(SPS) would be a huge spacecraft capturing the power of solar radiation in space and to supply electric power to the electric grid on the ground. The SPS concept was proposed by Dr. Peter Glaser in 1968. SPS have been studied now for exactly fifty years by many scientists in various countries. It has been regarded as one of the most promising energy projects of the future and has been attracting more attention in recent years. More and more Chinese scholars and experts are paying attention to the development of SPS. Due to the huge size, immense mass and high power of such a satellite system, there are many technical difficulties which exist to realize SPS. In this paper, recent SPS research and development activities are reviewed first. Various SPS concepts are analyzed and compared. The primary scheme of the Multi-Rotary joint SPS(MR-SPS) is described. The main feature is that the huge solar array comprising many separate small solar sub-arrays and each solar sub-array has two middle power rotary joints. So, the most challenging technology, the high-power rotary joint, is simplified by using many middlepower rotary joints hence the possibility of a single-point failure of a single rotary joint is avoided. This enables easy assembly of the modular solar arrays. Finally some key technologies of MR-SPS are analyzed.展开更多
The signatures of flux ropes with obvious core magnetic field are detected by ClusterⅡ at the dayside magnetopause during 11: 00-11: 15 UT on Mar. 2, 2001. The similar characteristics can be found from the magnetic f...The signatures of flux ropes with obvious core magnetic field are detected by ClusterⅡ at the dayside magnetopause during 11: 00-11: 15 UT on Mar. 2, 2001. The similar characteristics can be found from the magnetic field variations recorded by the four spacecrafts (Cluster Ⅱ C1-C4). All the three (-/+) bipolar signatures in the BN com-ponent are accompanied with enhancements of BM and mag-netic field strength B in the boundary normal coordinates (LMN coordinates). A MHD simulation with two dimensions and three components is performed to explore the reconnec-tion process driven by the incoming flow of solar wind at the dayside magnetopause. The numerical results can illustrate the recurrent formation of magnetic structures with a core magnetic field. The time history of the magnetic field B and three components Bx, By and Bz at a given point of the cur-rent sheet can reproduce the observational features of the events mentioned above.展开更多
The objective of the whole-spacecraft vibration isolation (WSVI) system is to reduce the launch-induced dynamic loads and the quality control cost of the satellite and its components, and to increase the launch reliab...The objective of the whole-spacecraft vibration isolation (WSVI) system is to reduce the launch-induced dynamic loads and the quality control cost of the satellite and its components, and to increase the launch reliability by insertion of isolators between the satellite and the launch vehicle. A niche hybrid genetic algorithm (NHGA) is proposed to optimize stiffness and damping of the isolators. Through the comparison of the frequency response analysis results, it shows that the optimized WSVI system more effectively reduces spacecraft axial / lateral response due to the broadband structure-born launch environment. At the same time, the case of the whole-spacecraft vibration isolation optimization design demonstrates the efficiency and validity of the genetic algorithm.展开更多
文摘Space debris is very dangerous to the security of on-the-orbit spacecrafts, and it is increasing in number at high speed with the expansion of human space exploration. Space debris has become a serious space pollutant noticed by many astronomers. The increase of space dust sources and the development of research on space dust urgently need space dust data sharing and exchanging. It is necessary for us to establish the Space Dust Database to realize the sharing and canonical management of the data. The Space Dust Database (SDD) management system, based on the 3-layer B/S computer mode, was designed and implemented in this paper. The system’s features include significantly improved runtime efficiency, good scalability and maintainability. The Space Dust Database can provide some scientific bases for the study of the chemical constituents, mineral composition, origin and sources of space dust, but also provide excellent data services and decision-making support for the protection of space and model construction of space dust.
基金Project supported by the National Natural Science Foundation of China(No.61525403)
文摘A spacecraft＇s separation parameters directly affect its flying trace. If the parameters exceed their limits, it will be difficult to adjust the flying attitude of the spacecraft, and the spacescraft may go off-track or crash. In this paper, we present a composite optimization method, which combines angular velocities with external moments for separation parameters of large-eccentricity pico-satellites. By changing the positions of elastic launch devices, the method effectively controls the popping process under the condition of less change in the separation mechanism. Finally, the reasons for deviation of angular velocities and unreliable optimization results are presented and analyzed. This optimization method is proved through a ground test which offsets the gravity. Simulation and test results show that the optimization method can effectively optimize the separation parameters of large-eccentricity pico-satellites. The proposed method adapts particularly to the fixed and non-stable status elastic parameters, the distribution of all kinds of elastic devices, and large-eccentricity spacecrafts for which attitude corrections are difficult. It is gen- erally applicable and easy to operate in practical applications.
基金PFC was financially supported by the Chinese foundations NSFC(11533005)Jiangsu 333 Project
文摘On May 4, 2018, as the chief engineer, Prof. SUN Weigang, signed his name on the Review Report, the Solar Ha Imaging Spectrometer spacecraft was finally approved by the Chinese Space Agency. This is the second spacecraft designated for solar observations in China, coming on the heels of the Advanced Space-born Solar Observatory （ASO-S）, which was approved by the Chinese Academy of Sciences on December 29, 2017. The approval of the two space missions for solar observations marks a milestone for the Chinese solar physics to glide into the space age.
文摘The Space Power Satellite(SPS) would be a huge spacecraft capturing the power of solar radiation in space and to supply electric power to the electric grid on the ground. The SPS concept was proposed by Dr. Peter Glaser in 1968. SPS have been studied now for exactly fifty years by many scientists in various countries. It has been regarded as one of the most promising energy projects of the future and has been attracting more attention in recent years. More and more Chinese scholars and experts are paying attention to the development of SPS. Due to the huge size, immense mass and high power of such a satellite system, there are many technical difficulties which exist to realize SPS. In this paper, recent SPS research and development activities are reviewed first. Various SPS concepts are analyzed and compared. The primary scheme of the Multi-Rotary joint SPS(MR-SPS) is described. The main feature is that the huge solar array comprising many separate small solar sub-arrays and each solar sub-array has two middle power rotary joints. So, the most challenging technology, the high-power rotary joint, is simplified by using many middlepower rotary joints hence the possibility of a single-point failure of a single rotary joint is avoided. This enables easy assembly of the modular solar arrays. Finally some key technologies of MR-SPS are analyzed.
基金supported by the National Natural Science Foundation of China(Grant No.40174042)the Major project of the National Natural Science Foundation of China,and partly by the Innovation Engineering Fund of USTC.
文摘The signatures of flux ropes with obvious core magnetic field are detected by ClusterⅡ at the dayside magnetopause during 11: 00-11: 15 UT on Mar. 2, 2001. The similar characteristics can be found from the magnetic field variations recorded by the four spacecrafts (Cluster Ⅱ C1-C4). All the three (-/+) bipolar signatures in the BN com-ponent are accompanied with enhancements of BM and mag-netic field strength B in the boundary normal coordinates (LMN coordinates). A MHD simulation with two dimensions and three components is performed to explore the reconnec-tion process driven by the incoming flow of solar wind at the dayside magnetopause. The numerical results can illustrate the recurrent formation of magnetic structures with a core magnetic field. The time history of the magnetic field B and three components Bx, By and Bz at a given point of the cur-rent sheet can reproduce the observational features of the events mentioned above.
基金The Natural Science Foundation of China(No. 60402003)The National High Technology and Development Program of China(No. 2002AA745120)
文摘The objective of the whole-spacecraft vibration isolation (WSVI) system is to reduce the launch-induced dynamic loads and the quality control cost of the satellite and its components, and to increase the launch reliability by insertion of isolators between the satellite and the launch vehicle. A niche hybrid genetic algorithm (NHGA) is proposed to optimize stiffness and damping of the isolators. Through the comparison of the frequency response analysis results, it shows that the optimized WSVI system more effectively reduces spacecraft axial / lateral response due to the broadband structure-born launch environment. At the same time, the case of the whole-spacecraft vibration isolation optimization design demonstrates the efficiency and validity of the genetic algorithm.
