May 2022, Volume 6 Issue 6
    

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  • Topic: High Speed Laser Information Transmission Technology of Deep Space
    High Speed Laser Information Transmission Technology of Deep Space Between Moon and Earth
    TAN Liying, SUN Zhenghu
    2019, 6(6): 515-522. https://doi.org/10.15982/j.issn.2095-7777.2019.06.001
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    The application of light wave for deep space information transmission will have the advantages of smaller terminal volume,mass and low power consumption under the same data rate,and the receiving sensitivity is high during the transmission process. Because of the narrow beam width,it can make the energy centralized and reach a long transmission distance. Using light wave as the information carrier of deep space exploration will have the advantages that the microwave band does not have. The feasibility of technology is described, and the research status of the moon earth laser information transmission technology is summarized,providing a reference for the development and engineering application of deep space laser communication in China.
  • Topic: High Speed Laser Information Transmission Technology of Deep Space
    Progress and Application Research of Deep Space Laser Communication
    LI Lianghai, LIU Xiangnan, LI Xiaoliang
    2019, 6(6): 523-529. https://doi.org/10.15982/j.issn.2095-7777.2019.06.002
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    Deep space laser communication is a key approach to achieve high-speed communication in deep space. In this paper,the development of foreign deep space laser communication is summarized,while some inspirations of deep space laser communication technology development are obtained. Then applications of deep space laser communication are proposed. Finally, key technologies involved are analyzed for promoting the development of China's deep space laser communication.
  • Topic: High Speed Laser Information Transmission Technology of Deep Space
    Pointing Accuracy of Lunar-Ground Laser Communication Based on J2 Perturbation
    GUO Pengzhen, LI Bo, KANG Dongpeng, YU Siyuan, WANG Qi, NAN Fang, TAN Liying, MA Jing
    2019, 6(6): 530-536. https://doi.org/10.15982/j.issn.2095-7777.2019.06.003
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    Based on the J 2 orbit prediction model, lunar satellites with various inclinations and orbital heights have been designed. Then, by comparing the simulation results of the J2 orbit prediction model with the direct integration RKF7 (8) simulation results,pointing accuracy of lunar-ground laser communication is studied. The laser communication terminal is installed on the -Y plane satellite deck in our simulation. To a certain extent,the results show that the J2 orbit prediction model can meet the requirements of lunar polar remote sensing satellites for lunar-ground laser communication. When the orbital height is 1 000 km and 2 000 km,the azimuth deviation of 10 min does not exceed 40 μrad,and the pitch angle deviation is only about 7 μrad. The orbit prediction model can satisfy the lunar-ground laser communication pointing requirements.
  • Topic: High Speed Laser Information Transmission Technology of Deep Space
    Analysis of Link Characteristics of High-Speed Laser Communication System in Lunar-Ground Link
    WANG Qi, MA Jing, TAN Liying, YU Siyuan, ZHOU Yuandong
    2019, 6(6): 537-544. https://doi.org/10.15982/j.issn.2095-7777.2019.06.004
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    According to the three-body motion of the Earth,the Moon and the lunar satellite,the occlusion problem of the Moon-Earth link and the link mode are analyzed. The simulation results show that when three MPO satellites are used for communication,the number of link interruptions will be greatly reduced,but in some certain periods,the communication link is still interrupted by the occlusion of the moon frequently. When using four MPO satellites for communication,the link will no longer be blocked by the Moon,but only blocked by the Earth. By the same token,increasing the number of geosynchronous orbiting satellites can avoid occlusion of the Earth. The simulation results show that the link is established by two GEO satellites, and the link will not be blocked by the Earth. An information relay center for deep space science research is established. The laser communication technology is used to achieve high-speed laser information transmission between the Moon and the Earth,providing support for the development of deep space exploration technology in China.
  • Topic: High Speed Laser Information Transmission Technology of Deep Space
    Research on EDFA Wavelength Division Multiplexing Performance under Deep Space Radiation
    LIU Qingfeng, LI Bo, KANG Dongpeng, YANG Qingbo, MA Jing, TAN Liying, YU Siyuan, ZHAO Sheng, WANG Qi
    2019, 6(6): 545-552. https://doi.org/10.15982/j.issn.2095-7777.2019.06.005
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    With the increasing demand for data capacity of deep space laser communication systems,the wavelength division multiplexing(WDM) technology will become an effective method to expand communication capacity. It is necessary to study the performance variation of EDFA WDM characteristics under deep space radiation conditions. The effects of deep space radiation and temperature field on the performance of EDFA,non-uniform characteristics are analyzed,and the gain influence model between EDFA WDM signals under deep space radiation conditions are established,and the evaluation method of the influence of nonuniform variation of gain is given. Deep space radiation environment was simulated, and the electron irradiation and neutron irradiation were used as radiation sources to simulate the effects of radiation ionization and radiation displacement,respectively. The correctness of the model is verified by experimental results. Using this model,the non-uniform characteristics of the gain of each wavelength of EDFA in WDM application under different types of radiation and different temperatures in deep-space radiation environment can be obtained,providing reference for WDM application of EDFA in deep space laser communication.
  • Article
    Link Assignment Algorithm Research on Earth-Moon Spatial Information Network
    LIU Bingyi, WANG Luqi, GUO Wei, ZHU Weige
    2019, 6(6): 553-560. https://doi.org/10.15982/j.issn.2095-7777.2019.06.006
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    When we design the topology,how to assign the numerable communication terminals on each satellite to build communication links,and then construct a well performing network topology,becomes a significant research problem. With the object of minimizing the average distance between lunar relay satellites to ground station, and subject to the communication terminal quantity on satellites as well as the connectivity between lunar relay satellites and ground station,we proposed the link assignment algorithm based on competitive decision(LAA-CD)and the link assignment algorithm based on simulated annealing (LAA-SA),and then compared the performances of those two algorithms with the greedy algorithm. The simulation result shows that both resulted topologies of LAA-CD and LAA-SA have shorter average distance than the greedy algorithm,and LAA-SA can greatly reduce the time complexity. This paper further compares two different constellations and finds out the network topology based on the lunar polar orbit satellite constellation always has a shorter average distance than the Earth-Moon Lagrange satellite constellation. It will provide technology support for the future satellite networks assignments.
  • Article
    Principle and Characteristics Analysis of Two-Way Scaling Transfer Slope of Mars Rover
    MA Chao, LIU Wei, MAN Jianfeng, LIU Fei, PAN Qiuyue, CHEN Ming, JIANG Shengyuan
    2019, 6(6): 561-569. https://doi.org/10.15982/j.issn.2095-7777.2019.06.007
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    China's first scheduled Mars exploration mission will be implemented in 2020,achieving the goal of surrounding, landing,and patrolling in one step. Among them,after the lander softly landing on the surface of Mars,whether the rover can be safely transferred to the surface of Mars along the transfer ramp is the key to the mission success. Based on the functional requirements of the rover's transfer ramp. In this paper, a two-way pumping ramp scheme is proposed,which solves the key problems of large exhibition ratio, drive sharing and reliable deployment, and its unfolding principle and mechanical characteristics are analyzed. The unfolding test in the simulated martian gravity environment is carried out to provide reference for the design of the Mars transfer ramp in China.
  • Article
    Orbit Prediction and Dynamical Analysis of Phobos
    GAO Wutong, XIE Pan, YAN Jianguo
    2019, 6(6): 570-579. https://doi.org/10.15982/j.issn.2095-7777.2019.06.008
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    In this paper,numerical integration is used to calculate and predict the orbit of one of the Martian moons,Phobos. First,the considered force models,parameters and integration methods are introduced. Then the effect of different force models and parameters are analyzed by simulation,and a suggested model is given according to the analysis result. Finally,the difference in position and orbital elements between the proposed model and existing ephemeris is compared. The result shows the same order in magnitude in comparison with the difference of the ephemeris themselves,which proves the precision and reliability of the proposed model. The Phobos dynamical force models analysis and the orbit prediction will help to the exploration missions of Phobos.
  • Article
    Remarks on Chinese Autonomous Exploration of the Liquid Oceans beneath the Icy Moons’Surfaces of Jupiter System
    XU Xiyu, ZHU Di, YANG Shuangbao
    2019, 6(6): 580-585. https://doi.org/10.15982/j.issn.2095-7777.2019.06.009
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    Icy Moons of Jupiter System (especially Europa) have abundant exploring value,and they are among the hottest objectives in solar system exploration throughout the world. In this paper,the recent advances in pertinent exploration technology in the international community are summarized, and some science issues, such as sub-surface model, temperature profile, penetration depth,and the influence of icy moons' ionosphere,are addressed. A few new ideas are presented,a preliminary system framework is proposed,and some simulation results of the sub-surface dielectric property are shown. The forthcoming Chinese autonomous Jupiter system exploration mission focusing on the exploration of the liquid oceans beneath the icy moons' surfaces is expected to benefit much from the investigation of new methodology and new configuration in this paper.
  • Article
    Research on Extensional Constraint Filtering Method Based on Dynamic Constraint Sets
    JIANG Xiao, XU Rui, CHEN Lijun
    2019, 6(6): 586-594. https://doi.org/10.15982/j.issn.2095-7777.2019.06.010
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    With the development of deep space missions and the complexity of scientific tasks, the autonomous mission planning and scheduling of deep space explorers has become a research hotspot. On the basis of the task characteristics and the analysis of the system constraints of deep space probes,combined the intelligent planning theory with the constraint satisfaction technology,the dynamic characteristics of the constraints in the multi-layer constraint programming model is studied,and the fast extensional constraint filtering algorithm is designed based on the dynamic constraint sets. In this method, the newly added activities are classified according to the conflict between activities in the domain information,and the consistency of variables in the constraint table are checked. The results show that the proposed algorithm can effectively reduce the number of invalid constraints in the constraint processing,reduce the algorithm backtracking in the process of problem processing,and improve the efficiency and success rate of the planning.
  • Article
    Development and Application of Modular Deep-Space Probe Based on On-Orbit Assembly and Maintenance
    LIU Huawei, LI Weijie, TIAN Baiyi, DING Jifeng, ZENG Fuming, WANG Yaobing, WANG Guangyua
    2019, 6(6): 595-602. https://doi.org/10.15982/j.issn.2095-7777.2019.06.011
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    Deep space exploration tasks are developing rapidly both at home and abroad. In recent years,a number of new deep space probe projects have been proposed,which are adopted modular design and on-orbit assembly and maintenance. On-orbit assembly and maintenance are the basic contents of spacecraft on-orbit service technology. Foreign countries have achieved fruitful results after decades of development in this field,and modular design is a major supporting technology for on-orbit assembly and maintenance of spacecraft. In this paper,the modular design and on-orbit assembly and maintenance programs in the deep space exploration are summarized,mainly including modular exoplanets landing probes,large on-orbit assembly deep space probe,the very large on-orbit assembly space telescope system in the SEL2 orbit,and so on. The key elements of the deep space probe modular design for the on-orbit assembly and maintenance are analyzed. At the same time,aiming at the technical requirements of long life,high reliability,special propulsion system and its supporting equipment of deep space exploration spacecraft,a multimission Mars probe system is proposed,which applies the on-orbit assembly and maintenance technology. The mission framework, the basic composition and the orbit strategy of the probe system are introduced. The above investigations and analyses will provide the reference for the development of the deep space detection technologies and the development of new deep space probes in China.
  • Article
    A Reliability Analysis Method for On-Orbit Repairable Single-Unit
    LI Jie, YANG Hong, QIAO Junqing, ZHAO Guoqing
    2019, 6(6): 603-608. https://doi.org/10.15982/j.issn.2095-7777.2019.06.012
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    During deep space exploration,the ability of being able to be repaired for an on-orbit unit can greatly improve the reliability of spacecraft system. However,researches on single-unit reliability with the influence caused by the on-orbit repair are really scarce. An availability model and its state equations of on-orbit repairable single-units are studied, and its transient availability formula is proposed. The availability with different repair rates of a repairable single-unit is calculated,and compared with a non-repairable one. A method for quick estimating the expected reliability at the end of mission by applying the relationship between repair rate and failure rate is presented. It is shown that the higher on-orbit repair rate,the higher reliability of a singleunit. The high on-orbit repair ability can also reduce the requirement on the reliability of a developing single-unit.