May 2022, Volume 1 Issue 2
    

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  • Review
    Development Trend Analysis of Solar System Explorationand the Scientific Vision for Future Missions
    ZHENG Yongchun, OUYANGZiyuan
    2014, 1(2): 83-92.
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    This paper summarizes the history of solar system exploration and the major scientific achievements.We can find out significant trends for future solar system exploration.Firstly,from the Moon to the Mars is theMain line for future solar system exploration.China has carried out three lunar missions.The next objective bodyWill focus on the Mars.Secondly,the general survey of the solar system is not popular as be fore.Future solarSystem exploration will focus on some high interested asteroids,planet sand their moons.Thirdly,the solar systemExploration in the last century was focused on technology realization,while that in the new century will be driven byscience.Fourthly,we must face the technology difficulties,shortage of professionals,and unaffordable budgets in The solar system missions These problems are difficult for any country to solve by itself.Therefore,international Cooperation is necessary and needed.This paper also analyzes the three major science themes of the solar system exploration:the origin and evolution of the solar system and planets,and the search for extraterrestrial life and Habitable environment,guard against the catastrophic events of the strong solar activity and asteroid impact on the Earth.With the progress of China’s Lunar Exploration Program,China should carry out its Mars mission as soon as possible.After that,China will promote its missions to the asteroids,Sun,Venus,Jupiter system,and otherbodies.
  • Review
    Review of Orbital Dynamicsin the Vicinity ofSolar System Small Celestial Bodies
    YU Yang, BAOYIN Hexi
    2014, 1(2): 93-104.
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    The orbital dynamics in the vicinity of solar system small bodies(SSSB) is an important aspect of modern celestial mechanics, which has abundant physical phenomenon and may offer a deep insight into the referred dynamics. During last two decades,several deep space probes have been sent to SSSB for in-situ explorations of these small worlds, which high lighted the orbital dynamics in around SSSB as one of the biggest challenges in space engineering.This paper first reviewed the history of SSSB studies and explorations, and gave a summary on the generality and merit of the orbital dynamics.Then we introduced indetail the developments of astronautics,planetary science and nonlinear dynamics on this issue,and presented the relevant hot topics in these fields.Based on the reviews, the last part of this paper attempted to outline the tendency of future researches on this issue.
  • Review
    Key Technologies in the Chang’e-3 Soft-Landing Project
    WU Weiren, YU Dengyun
    2014, 1(2): 105-109.
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    On Dec.14,2013,Chang’e-3 lunar probe successfully landed on the Rainbow Bay area at44.12°N/19.51°W of the moon,then the lunar lander and rover successfully separated and took photos of each other,which achieved the mission objective of our nation’s first soft landing and roving exploration on a celestial body beyond the Earth,and made China the third country achieving lunar soft landing after the UnitedStates and the former SovietUnion.In this paper,based on the briefint roduction of the development process of Chang’e-3 project,the key technologies of the project are summarized
  • Article
    Navigation,Guidance and Control of Mars Science Laboratory in Cruis
    HOU Jianwen, ZHOU Jie
    2014, 1(2): 110-116.
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    The guidance,navigation and control system,the restrict condition of cruise trajectory,the control strategy design and its implementation process of the recent U.S. Mars landing mission,Mars Science Laboratory,are introduced.Then the experience of cruise navigation,guidance and control is analyzed and summarized.This paper has some reference to future Mars exploration mission of China.Some suggestions including establishing strictflight path control strategy by Monte Carlo method,studying non-gravitation effect,fining various fault scenario,choosing appropriate injection aim point,and increasing the space measurement and control station abroad.
  • Article
    Three-Dimensional Analytical Model for Mars Atmospheric Density
    QIN Tong, WANG Shuo, GAO Ai, ZHU Shengying, CUI Pingyuan
    2014, 1(2): 117-122.
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    This paper utilizes the data from the Mars atmosphere database and establishes a three-dimensional analytical atmospheric density model of Mars with the altitude,longitude and latitude as its input..The layered exponential model is adopted vertically.At horizontal direction,the reference density and reference altitude are assumed to be polynomial functions of longitude and latitude.The coefficients of the polynomial are obtained bysurface fitting which is based on the method of least squares.Compared with the traditional exponential density model,the3-D model proposed in this paper expresses the variation of density with not only altitude but also long itude and latitude.Compared with the Mars atmosphere data,the 3-D model has an analytical formulation and requires less calculation time.As long as the polynomial coefficients are stored in simulation,the real-time calculation and calling of the atmospheric density can be achieved,which applies to the ground real-time simulation.
  • Article
    Automatic Detection of Martian Impact CratersBased on Digital Elevation Model
    ZHANG Tengyu, JIN Shuanggen, CUI Hutao
    2014, 1(2): 123-127.
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    Due to uncertainties of illumination and incidence in image processing,a method that impact craters are automatically detected and recognized based on the DEM from Mars Orbiter Laser Altimetery (MOLA) aboard Mars Global Surveyor (MGS) is proposed in this paper.Topographic curvature,which delineates impact craters,can be deduced from topography data.The thresholding map of curvature is transformed in to a binary map,from which we can detect impact craters by combination of segmentation and flooding algorithms.The true rate is 73.4% in detecting craters.More impact craters on Mars with confirmation algorithm can be effectively detected truly,which are added to the existing catalog of manually identified Martian craters.
  • Article
    Mars Entry Trajectory Tracking Using Constrained Predictive Control
    WU Chao, ZHAO Zhenhua, YANG Jun, LI Shihua, GUO Lei
    2014, 1(2): 128-133.
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    Aiming at tracking the vehicle’s entry optimized trajectory for Mars Landing,a new method based on constrained predictive control is proposed.The vehicle’s nonlinear dynamics,the initial state uncertainties, saturation limit of the control input and the parameter perturbation are taken into consideration synthetically.A constrained predictive control (CPC) is developed which consists of a linearized step-response predictive model,feedback correction and constrained rolling optimization.The simulation results indicate that:constrained predictive control has a more accurate guidance command tracking performance compared with the PID method,therefore its radius error at the parachute deploying point is far smaller than that of the PID method;a smooth control curve canbe obtained under the saturation constraint of the control input.
  • Article
    Impact Analysis of Dynamic Parameters Uncertaintyon Small Celestial Body Landing
    YUAN Xu, ZHU Shengying, QIAO Dong, CUI Pingyuan
    2014, 1(2): 134-139.
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    To the challenge of high degree irregularity,complex gravity field and relatively high degree of physical parameters uncertainty of small celestial bodies,the impact of dynamic parameters uncertainty is analyzed,based on the approximate linearized analytical solution of the small celestial body landing dynamic equations.A calibrating method is used to compensate the errors brought in by linearization.And the sensitivity equations ofspacecraft trajectories to dynamic parameters are established.Taking the asteroid Eros 433 as an example,the impact of the uncertainty of the mass,rotation rate and gravitational potential coefficients of the target body on the spacecraft landing trajectory,the initial state of the spacecraft and the thrust acceleration are analyzed elaborately.Mathematical simulation shows that for this selected target body,the thrust acceleration disturbance is the primary factor of such impact,and the initial state of the spacecraft the secondary one.And the impact of other parameters are relatively small
  • Article
    3D Shape Reconstruction for Small Celestial Body Based on Sequence Images
    LAN Chaozhen, GENG Xun, XU Qing, CUI Pingyuan
    2014, 1(2): 140-145.
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    A method for 3D shape reconstruction of small celestial body based on sequence images is proposed.Using the internal geometric constraints of sequence images,the relative position and attitude parameters ofsequence images are estimated based on sparse bundle adjustment.In order to reconstruct the 3D shape of the small celestial body,such solutions as epipolar line geometric constraints,semi-global matching strategy and multi-view least squares matching are combined to perform dense image matching.In order to solve the mis-matching problem caused by the different scale and lack of texture details,the search strategy of random KD tree and RANSAC method with perspective model are used to detect outliers.Then,the 3D shape of VESTA is reconstructed using the method above by sequence images obtained from the Dawn mission.The results demonstrate our method’s effectiveness.
  • Article
    Analysison Interferometric Tracking Technology by ChinaDeep Space Network in the Chang’e-3 Mission
    TANG Geshi, HAN Songtao, CHEN Lue, CAO Jianfeng, REN Tianpeng, WANG Mei
    2014, 1(2): 146-149.
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    Based on the first implementation of interferometric tracking technology in the Chang’e-3 projectby China DSN (DeepSpaceNetwork),this paper describes the differential interferometric tracking technique with the sparse quasar calibration.And the tracking data during Chang’e-3’s cruise to the moon is analyzed as well. Compared with high accuracy orbit ephemeris,time delay observation error is less than 1ns which corresponds to anangular accuracy of about 90nrad.And delay rate error is below 1ps/s.Interferometric tracking has played an important role in Chang’e-3 project.
  • Article
    Dynamic Analysis of Landing Impact for Deep Space Reentry Capsules
    ZHANG Dapeng, LEI Yongjun
    2014, 1(2): 150-155.
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    Firstly the finite element model including the deep space reentry capsule and landing bed for dynamic analysis of landing impact is established.Then the parameters of the landing bed are calibrated according to the experimental data of Shenzhou spacecraft.The landing impact of deep space reentry capsule is simulated and analyzed by using LS-DYNA.The landing attitude change,the stress distribution,the acceleration response curves of the key point and the impact energy absorption are got according to the simulation and analyses of the landing impact in the typical working conditions.These results can provide reference to the structural optimization,the landing attitude selection and the study to ground test for deep space exploration reentry capsules.
  • Article
    A Conception of Mars Multi-mode Combination Exploration Mission
    CHEN Ying, ZHOU Lu, WANG Li
    2014, 1(2): 156-160.
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    Focusing on the requirements of scientific findings and Mars exploration mission innovations,and exploring advanced exploration modes,a novel scenario of Mars multi-mode combination exploration mission is proposed.Its characteristics rest with the combination of several exploration modes such as orbiting,landing,multi-point penetrating and ballooning,and consequently three-dimensional multi-layer and multi-source informationis obtained and scientific exploration is carried out in depth through one mission. Therefore,Mars can be exploredin three-dimensional multi-mode combinational ways,which not only develops the capability and technology for exploration activity but also helps to get a good grasp of Mars and heighten a comprehensive effect of exploration activity.The design results of multi-mode combination exploration not only apply to Mars exploration but also help to explore other extraterrestrial bodies such as Venus and Saturn.