Jan 2022, Volume 9 Issue 1
    

  • Select all
  • Special Issue：Technology and Application of Deep Space Exploration
    A High-reliability and Scalable Lunar Surface Power Distribution Network Frame Vision Based on Micro-nuclear Reactor
    XIA Yan, HUANG Wen, FENG Yu, JIN Zhangtao, OU Xuedong, XU Jinghao, SHUAI Zhikang
    2022, 9(1): 3-13. https://doi.org/10.15982/j.issn.2096-9287.2022.20210138
    Download PDF
    The lunar surface distribution grid is the long-term stable power source and skeleton support for the lunar scientific research station. The miniature nuclear reactor is light in weight, compact in structure, and extensible in scale. It can provide a long-lasting energy source for the power generation devices of the lunar scientific research station. To meet the needs of lunar scientific research tasks and the construction of large-scale lunar bases in the future, the lunar power distribution grid must have high reliability and scalability. Therefore, a high-reliability and scalable power distribution grid, integrated with micro nuclear reactors, for the lunar surface, as well as its relevant reliability guarantee technologies was proposed in this paper. The feasibility and advantages of the power distribution grid frame proposed were discussed from the perspectives of the topology, partition interconnection and operation control methods of the distribution grid. This vision is aimed to provide inspiration for manned moon landing and extraterrestrial base construction plans.
  • Special Issue：Technology and Application of Deep Space Exploration
    Determination of the Orbit of Chang’E-4 Relay Satellite Under Sparse Observation
    LIU Siyu, HUANG Yong, LI Peijia, YANG Peng
    2022, 9(1): 14-20. https://doi.org/10.15982/j.issn.2096-9287.2022.20210071
    Download PDF
    Chang’E-4 relay satellite successfully entered the Earth-Moon L2 Halo orbit on June 14, 2018, and assumed the data transmission function between the ground-based measurement and control station and Chang’E-4 lander. At present, Chang’E-4 relay satellite is in sparse observation mode, with an average of 4~5 days for each observation. This paper analyzes the orbit determination accuracy of Chang’E-4 relay satellite circling the Earth-Moon L2 in January 2021. The orbit accuracy of the relay satellite around the L2 point is better than 2km, and the arc including the VLBI delay and delay rate reaches the level of 100 meters. Under the premise of VLBI observation, reasonable allocation of the coverage period of the ranging and velocity measurement arcs can effectively improve the orbit accuracy under the same data coverage.
  • Special Issue：Technology and Application of Deep Space Exploration
    Regenerative Pseudo-Random Code Ranging Orbit Determination Accuracy Analysis for Chang’E-4 Relay Satellite
    NIU Dongwen, DUAN Jianfeng, OUYANG Qi, ZHANG Yu, CHEN Lue, WANG Mei
    2022, 9(1): 21-28. https://doi.org/10.15982/j.issn.2096-9287.2022.20191213002
    Download PDF
    Flying on the mission orbit at the Earth-Moon L2, the Chang'e-4 relay sattellite carried out the experiment of regenerative pseudo-random code ranging, during which the regenerative pseudo-random code ranging and the sidetones ranging were both utilized. The regenerative pseudo-random code ranging data and the side tone ranging data of the Chang’E 4 relay satellite, which are flying on the mission orbit at the Earth-Moon L2 libration point, are used to evaluate their orbit determination accuracies. The results show that the RMS of the regenerative pseudo-random code ranging data is one order of magnitude better than that of the sidetones ranging data, and the orbit determination and prediction accuracy of the regenerative pseudo random code ranging data is twice as good as that of the side tone ranging data. This is a reliable reference for the application of regenerative pseudo-random code ranging in the future Chinese deep space exploration missions.
  • Special Issue：Technology and Application of Deep Space Exploration
    System Design and Experimental Verification of Mobile Lunar Lander
    JIA Shan, ZHOU Xianghua, CHEN Jinbao, WANG Yongbin, ZHAO Jianhua, ZHANG Sheng
    2022, 9(1): 29-41. https://doi.org/10.15982/j.issn.2096-9287.2022.20210141
    Download PDF
    A mobile lunar lander was proposed to address the problem that the conventional surface lander, which cannot actively adjust attitude and flexibly roam, is not suitable for future missions such as large-scale surface exploration and surface base construction. Firstly, the system composition of the mobile lunar lander and the composition of each subsystem were introduced. Secondly, the functions and implementation of the variable configuration body and the buffering/driving integrated buffer were introduced. Thirdly, a kinematic model of the buffering/walking integrated leg-foot mechanism was established, the walking gait and turning gait with fewer posture adjustment times were designed, and the trajectories of the joints of the leg-foot mechanism under the conditions of foot-end stepping and whole-unit posture adjustment were planned. The gait simulation was completed by building a virtual prototype model of the whole machine. Finally, a walking test prototype was developed and a test auxiliary facility was built, and the walking gait experiment was completed. The results show that the proposed mobile lander gait design is reasonable, the motion trajectory of the active drive joints is smooth and supple, the lander body has no large undulation and deflection during the movement, the walking speed can reach 0.01m/s, and the turning speed can reach 0.6°/s.
  • Special Issue：Technology and Application of Deep Space Exploration
    Analysis of High Resolution SAR Data and Selection of Landing Sites in the Permanently Shadowed Region on the Moon
    LIU Niutao, SHI Xianzheng, XU Feng, JIN Yaqiu
    2022, 9(1): 42-52. https://doi.org/10.15982/j.issn.2096-9287.2022.20210134
    Download PDF
    There is no direct solar illumination in the permanently shadowed regions (PSR) at the polar region of the Moon. Detecting water-ice in PSR is a significant scientific question. Until now, no spacecraft has landed in PSR. Chang’E-7 mission plans a rover landing at the solar illuminated region near PSR. A mini-flyer carried by the lander will fly to the PSR to collect regolith samples for analysis. Selection of landing site and sampling site is critical for the mission. The Polarization Synthetic Aperture Radar (Pol-SAR) onboard Chang’E-7 satellite can evaluate the roughness of lunar surface, the landing site, the sampling site and the flying trajectory with the assistance of high-resolution digital elevation model. By comparing the SAR data acquired by the Mini-RF onboard Lunar Reconnaissance Orbiter with the optical images at the solar illuminated region, we analyze the role that Pol-SAR play in selecting the flat landing site and sampling site. Regions near Hyginus crater and the landing site of Chang’E-4 mission are taken as examples. HRNet is used in lunar SAR image segmentation. The application of neutral network in lunar SAR image segmentation is discussed. Craters Shoemaker and Shackleton at lunar south pole are analyzed to find flat surface in PSR as potential landing sites. This paper provides a reliable reference for SAR detection in Chang’E-7 mission.
  • Special Issue：Technology and Application of Deep Space Exploration
    Design and Verification of Relay Communication System During Entry Descent and Landing for Tianwen-1 Mars Probe
    ZHANG Ting, HAN Yu, SUN Zezhou, RAO Wei, QIANG Huiping, BAI Fan, XUE Ji
    2022, 9(1): 53-61. https://doi.org/10.15982/j.issn.2096-9287.2022.20210131
    Download PDF
    Tianwen-1 Mars exploration mission is a mission for China to “Orbit, Fall and Patrol” Mars though a launch. Entry, Descent and Landing (EDL) of Mars exploration mission is a key part in the whole mission process. Based on the characteristics of relay communication task in this process, this paper introduces the relay communication system scheme and key technology of Tianwen-1 Mars probe adapted to the characteristics of complex timing，high autonomy, black barrier phenomenon and high dynamics of EDL segment communication task. At the same time, combined with the landing mission of Tianwen-1, the in orbit verification of relay communication in EDL is summarized and analyzed. The relay communication scheme proposed in this paper successfully supports the relay communication mission of the EDL section of the Mars Exploration of Tianwen-1.
  • Special Issue：Technology and Application of Deep Space Exploration
    High Precision Localization of Zhurong Rover Based on Multi-source Images
    WANG Jia, LI Dafei, HE Ximing, CHENG Ziqing, XU Qian, QIAN Xueru, WAN Wenhui
    2022, 9(1): 62-71. https://doi.org/10.15982/j.issn.2096-9287.2022.20210124
    Download PDF
    Zhurong rover landed on the southern part of Utopia Planitia of Mars on 15 May, 2021(UTC+8), marking that China successfully fulfilled the goals of “orbiting, landing on and roving around” Mars on its own for the first time. Localization of the rover is critical for supporting science and engineering operations in planetary rover missions, such as rover traverse planning and hazard avoidance. This paper introduced the localization method of Zhurong rover based on multi-source images in detail. Based on the coarse-to-fine strategy, the accurate landing positioning was achieved in the Digital Orthophoto Map (DOM) generated by the high resolution orbiter-image. Using the ground correction method combining relative localization and absolute localization, high-precision continuous localization of the rover was realized. Simulation experiment shows that the localization accuracy of the lander was within a pixel of the DOM generated by the high resolution orbiter-image, and the relative localization accuracy based on the Bundle Adjustment (BA) was better than 3% when the distance was about 10 meters. The methods have been successfully applied to the localization of Zhurong rover. The high-precision localization results greatly support the rover’s efficiently roving on Mars surface and avoiding potentially dangerous regions.
  • Special Issue：Technology and Application of Deep Space Exploration
    Design and Construction of a Simulating and Testing System for the Remote Operation of Planetary Surface Exploration
    LI Lichun, LI Jian, WANG Jia, YU Tianyi, LIU Chuankai, LI Nan, WAN Wenhui
    2022, 9(1): 72-79. https://doi.org/10.15982/j.issn.2096-9287.2022.20210133
    Download PDF
    According to the requirements and characteristics of simulation and verification for celestial surface remote operating, a simulating and testing system is build for remote operation of planetary rover. The system is composed of the 3D terrain environment, a simulating planetary rover, a terrain scanning system and a remote operating testing software. The simulated deformable 3D terrain is made of large man-made sand. A simulated planetary vehicle is installed with sensing cameras, movable mechanisms]. A method of terrain survey, rover position and gesture measurement based on laser scanning is proposed. A simulation and verification system for celestial surface exploration teleoperation based on simulation scene and planetary rover is established. The system is used in the simulation and verification of the key operational processes of Mars surface exploration, such as perception and planning, and provides strong support for the practical implementation of celestial surface remote operation.
  • Special Issue：Technology and Application of Deep Space Exploration
    Design and Application of Flexible Intelligent System for Sampling on the Extraterrestrial Body
    DENG Xiangjin, JIN Shengyi, ZHENG Yanhong, PENG Jing, YAO Meng, SHI Wei
    2022, 9(1): 80-87. https://doi.org/10.15982/j.issn.2096-9287.2022.20210128
    Download PDF
    Sampling of extraterrestrial bodies is an important development direction for future deep space exploration. Different from low Earth orbit missions, sampling of extraterrestrial bodies is usually restricted by many factors, such as long communication delay, limited energy and unstructured mission execution environment. On the one hand, the ground system cannot support such tasks in real time, which requires the spacecraft to have high autonomy. On the other hand, the limited computing resources of the system on the spacecraft and the high uncertainty of the mission environment lead to the complexity and low reliability of the fully autonomous design on the spacecraft, which still needs the decision support from the ground system to a large extent. The two contradictory aspects affect and hinder the smooth implementation of the task. According to this, in this article, through the analysis of celestial sampling system and its demand for artificial intelligence technology, a celestial sampling flexible system was designed and constructed based on artificial intelligence technology, to systematically support task execution task function modules by flexible configuration of the spacecraft and the ground system in the process, so as to gradually achieve high spacecraft autonomous ability to improve the efficiency of task execution. The system has been verified and applied in Chang’e-5 sampling package test, and the verification results show that the efficiency and reliability of sampling tasks can be significantly improved with the support of the system.
  • Special Issue：Technology and Application of Deep Space Exploration
    Design of a Sensorless Liquid Hydrogen Circulation Precooling Control System for Rockets
    ZHANG Xueying, MU Hui, LU Di, LU Wei, HUANG Hui, LI Dong
    2022, 9(1): 88-98. https://doi.org/10.15982/j.issn.2096-9287.2022.20210063
    Download PDF
    Circulation precooling driven by pump is used by Large-Thrust Hydrogen/Oxygen rocket engine of CZ-5 Launch Vehicle. The Circulation precooling pump of liquid hydrogen is driven by a permanent magnet synchronous motor. The circulation precooling control system control the motor of circulation precooling pump by sensorless vector control technology. This paper introduces the scheme of circulation precooling control system, expounds the key technology design, such as coordinate transformation and mathematical modeling, space vector pulse width modulation technology, sensorless control technology and so on, The two cable design methods are compared and analyzed in this paper. The research contents of period of oscillation, pump resonance in liquid nitrogen and motor stall in liquid hydrogen are simulated to verify the system design in liquid nitrogen and liquid hydrogen environment. The results show that the circulation precooling control system with sensorless vector control technology has the advantages of simple installation， flexible speed regulation and strong adaptability to load change.