The Cube Sat refers to the low-cost nano satellite produced by international standards. The QB50 project is "an International Network of 50 double Cube Sats for multi-point, in-situ, long-duration measurements in...The Cube Sat refers to the low-cost nano satellite produced by international standards. The QB50 project is "an International Network of 50 double Cube Sats for multi-point, in-situ, long-duration measurements in the lower thermosphere and re-entry research". There are 23 countries and region participated in the QB50 Project. 38 Cube Sats were developed and launched. Among them, four Cube Sats developed by Chinese universities were sent to orbit(Three were deployed from the International Space Station, and one was launched by the Polar Satellite Launch Vehicle, PLSV). They are Aoxiang-1(Northwestern Polytechnical University, the Asia coordinator), Lilac Sat-1(Harbin Institute of Technology), NJUST-2(Nanjing University of Science and Technology) and NUDTsat(National University of Defense Technology). Through the development of the QB50 Project, Chinese researchers and students got in touch with the concept of Cube Sat and gained experience of international scientific cooperation. A lot of students took part in the assembly, integration, and test of spacecraft, which is helpful to the training of space talents. Now, many universities and institutes have the capabilities to develop Cube Sats and the subsystems independently.展开更多
Because of their volume and power limitation, it is difficult for CubeSats to configure a traditional propulsion system. Atmospheric drag is one of the space environmental forces that low-orbit satellites can use to r...Because of their volume and power limitation, it is difficult for CubeSats to configure a traditional propulsion system. Atmospheric drag is one of the space environmental forces that low-orbit satellites can use to realize orbit adjustment. This paper presents an integrated control strategy to achieve the desired in-track formation through the atmospheric drag difference, which will be used on ZJUCubeSat, the next pico-satellite of Zhejiang University and one of the participants of the international QB50 project. The primary mission of the QB50 project is to explore the near-Earth thermosphere and ionosphere at the orbital height of 90-300 km. Atmospheric drag cannot be ignored and has a major impact on both attitude and orbit of the satellite at this low orbital height. We conduct aerodynamics analysis and design a multidimensional nonlinear constraint programming （MNLP） strategy to calculate different desired area-mass ratios and corresponding hold times for orbit adjustment, taking both the semimajor axis and eccentricity into account. In addition, area-mass ratio adjustment is achieved by pitch attitude maneuver without any deployable mechanism or corresponding control. Numerical simulation based on ZJUCubeSat verifies the feasibility and advantage of this design.展开更多
文摘The Cube Sat refers to the low-cost nano satellite produced by international standards. The QB50 project is "an International Network of 50 double Cube Sats for multi-point, in-situ, long-duration measurements in the lower thermosphere and re-entry research". There are 23 countries and region participated in the QB50 Project. 38 Cube Sats were developed and launched. Among them, four Cube Sats developed by Chinese universities were sent to orbit(Three were deployed from the International Space Station, and one was launched by the Polar Satellite Launch Vehicle, PLSV). They are Aoxiang-1(Northwestern Polytechnical University, the Asia coordinator), Lilac Sat-1(Harbin Institute of Technology), NJUST-2(Nanjing University of Science and Technology) and NUDTsat(National University of Defense Technology). Through the development of the QB50 Project, Chinese researchers and students got in touch with the concept of Cube Sat and gained experience of international scientific cooperation. A lot of students took part in the assembly, integration, and test of spacecraft, which is helpful to the training of space talents. Now, many universities and institutes have the capabilities to develop Cube Sats and the subsystems independently.
基金Young Scholars of China （No. 61525403） and the National Natural Science Foundation of China （No. 61503334）
文摘Because of their volume and power limitation, it is difficult for CubeSats to configure a traditional propulsion system. Atmospheric drag is one of the space environmental forces that low-orbit satellites can use to realize orbit adjustment. This paper presents an integrated control strategy to achieve the desired in-track formation through the atmospheric drag difference, which will be used on ZJUCubeSat, the next pico-satellite of Zhejiang University and one of the participants of the international QB50 project. The primary mission of the QB50 project is to explore the near-Earth thermosphere and ionosphere at the orbital height of 90-300 km. Atmospheric drag cannot be ignored and has a major impact on both attitude and orbit of the satellite at this low orbital height. We conduct aerodynamics analysis and design a multidimensional nonlinear constraint programming （MNLP） strategy to calculate different desired area-mass ratios and corresponding hold times for orbit adjustment, taking both the semimajor axis and eccentricity into account. In addition, area-mass ratio adjustment is achieved by pitch attitude maneuver without any deployable mechanism or corresponding control. Numerical simulation based on ZJUCubeSat verifies the feasibility and advantage of this design.
