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Characteristics of the lunar samples returned by the Chang'E-5 mission

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National Science Review 2022年第2期9卷 21-33页

作者： Chunlai Li Hao Hu Meng-Fei Yang Zhao-Yu Pei Qin Zhou Xin Ren Bin Liu Dawei Liu Xingguo Zeng Guangliang Zhang Hongbo Zhang Jianjun Liu Qiong Wang Xiangjin Deng Caijin Xiao Yonggang Yao Dingshuai Xue Wei Zuo Yan Su Weibin Wen Ziyuan Ouyang Key Laboratory of lunar and Deep space exploration National Astronomical Observatories Chinese Academy of Sciences lunar exploration and space Engineering center Beijing Institute of spacecraft System Engineering Department of Nuclear Physics China Institute of Atomic Energy State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Institute of Geochemistry Chinese Academy of Sciences

Forty-five years after the Apollo and Luna missions returned lunar samples,China’s Chang’E-5(CE-5)mission collected new samples from the mid-latitude region in the northeastern Oceanus Procellarum of the *** study shows that 95% of CE-5 lunar soil sizes are found to be within the range of 1.40-9.35 μm,while 95% of the soils by mass are within the size range of 4.84-432.27 μ*** bulk density,true density and specific surface area of CE-5 soils are 1.2387 g/cm~3,3.1952 g/cm~3 and 0.56 m~2/g,*** from the CE-5 regolith are classified into igneous clasts(mostly basalt),agglutinate and glass.A few breccias were also *** minerals and compositions of CE-5 soils are consistent with mare basalts and can be classified as low-Ti/low-Al/low-K type with lower rare-earth-element contents than materials rich in potassium,rare earth element and ***-5 soils have high FeO and low Mg index,which could represent a new class of basalt.

关键词： Chang’E-5 lunar soils physical properties petrography mineralogy chemistry

Primordial black hole mass functions as a probe of cosmic origin

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 164-171页

作者： Yi-Fu Cai Chengfeng Tang Geyu Mo Sheng-Feng Yan Chao Chen Xiao-Han Ma Bo Wang Wentao Luo Damien A.Easson Antonino Marcianò Deep space exploration Laboratory/School of Physical Sciences University of Science and Technology of ChinaHefei 230026China CAS Key Laboratory for Researches in Galaxies and Cosmology/Department of Astronomy School of Astronomy and Space ScienceUniversity of Science and Technology of ChinaHefei 230026China Istituto Nazionale di Fisica Nucleare(INFN) Sezione di MilanoMilano 20146Italy DiSAT Universitàdegli Studi dell'InsubriaComo 22100Italy Jockey Club Institute for Advanced Study The Hong Kong University of Science and TechnologyHong KongChina Department of Physics Arizona State UniversityTempe 85287-1504USA Department of Physics&center for Field Theory and Particle Physics Fudan UniversityShanghai 200433China Laboratori Nazionali di Frascati INFN Via Enrico Fermi 541 Frascati(Roma)00044Italy INFN sezione Roma Tor Vergata Rome I-00133Italy School of Physics University of Electronic Science and Technology of ChinaChengdu11731China

We discuss a novel window to probe the origin of our universe via the mass functions of primordial black holes(PBHs).The mass functions of PBHs are simply estimated using the conventional Press-Schechter formalism for two paradigms of cosmic origin,including inflationaryΛCDM and bounce *** standard inflationaryΛCDM model cannot generate an appreciable number of massive PBHs;however,non-trivial inflation models with blue-tilted power spectra at small scales and matter bounce cosmology provide formation mechanisms for heavy PBHs,which in turn,may seed the observed supermassive black holes(SMBHs).By fitting the SMBH mass functions at high redshift(z~6)derived from Sloan Digital Sky Survey(SDSS)and Canada-France High-z Quasar Survey(CFHQS)quasars,for two paradigms of cosmic origin,we derive constraints on the PBH density fraction fPBHat z~6 and the characteristic mass M_(★),with the prior assumption that all SMBHs stem from *** demonstrate that this newly proposed procedure,relying on astronomical measurements that utilize deep-field surveys of SMBHs at high redshift,can be used to constrain models of cosmic ***,although not the main focus of this paper,we evolve the mass function from z~6 to z~0 through an assumption of 3×10^(8)-year Eddington’s accretion,and give a rough estimation of fPBHat z~0.

关键词： origin cosmic massive

Rescheduling of observing spacecraft using fuzzy neural network and ant colony algorithm

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Chinese Journal of Aeronautics 2014年第3期27卷 678-687页

作者： Li Yuqing Wang Rixin Xu Minqiang Deep space exploration Research center Harbin Institute of Technology

This paper aims at rescheduling of observing spacecraft imaging plans under uncertainties. Firstly, uncertainties in spacecraft observation scheduling are analyzed. Then, considering the uncertainties with fuzzy features, this paper proposes a fuzzy neural network and a hybrid rescheduling policy to deal with them. It then establishes a mathematical model and manages to solve the rescheduling problem by proposing an ant colony algorithm, which introduces an adaptive control mechanism and takes advantage of the information in an existing schedule. Finally, the above method is applied to solve the rescheduling problem of a certain type of earth-observing satellite. The computation of the example shows that the approach is feasible and effective in dealing with uncertainties in spacecraft observation scheduling. The approach designed here can be useful in solving the problem that the original schedule is contaminated by disturbances.

关键词： Ant colony algorithm Planning and scheduling Rescheduling spacecraft observing Uncertainty

Fault detection of flywheel system based on clustering and principal component analysis

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Chinese Journal of Aeronautics 2015年第6期28卷 1676-1688页

作者： Wang Rixin Gong Xuebing Xu Minqiang Li Yuqing Deep space exploration Research center Harbin Institute of Technology

Considering the nonlinear, multifunctional properties of double-flywheel with closed- loop control, a two-step method including clustering and principal component analysis is proposed to detect the two faults in the multifunctional flywheels. At the first step of the proposed algorithm, clustering is taken as feature recognition to check the instructions of ＂integrated power and attitude control＂ system, such as attitude control, energy storage or energy discharge. These commands will ask the flywheel system to work in different operation modes. Therefore, the relationship of parameters in different operations can define the cluster structure of training data. Ordering points to identify the clustering structure （OPTICS） can automatically identify these clusters by the reachability-plot. K-means algorithm can divide the training data into the corresponding operations according to the teachability-plot. Finally, the last step of proposed model is used to define the rela- tionship of parameters in each operation through the principal component analysis （PCA） method. Compared with the PCA model, the proposed approach is capable of identifying the new clusters and learning the new behavior of incoming data. The simulation results show that it can effectively detect the faults in the multifunctional flywheels system.

关键词： Attitude control Cluster analysis Energy storage Fault detection Flywheels

Disturbance observer-based robust guidance for Mars atmospheric entry with input saturation

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Chinese Journal of Aeronautics 2015年第3期28卷 845-852页

作者： Zheng Yiyu Cui Hutao Deep space exploration Research center Harbin Institute of Technology

Abstract With low-lifting capability taken into account, a robust guidance law for Mars entry vehicles with low lift-l：o-drag ratios, such as Mars Science Laboratory （MSL）, is presented. Consider the nonlinear term in the drag dynamic equation and bounded disturbances as a lumped disturbance, and design a linear disturbance observer （DOB） to estimate it. With the consideration of the control input saturation, an innovative sliding surface and a virtual system are introduced to design the guidance law. Analyses of disturbance observer performance and Lyapunov-based transient performance are also presented. It is shown explicit choices of design parameters. Simulation guidance law. that the drag tracking error can be adjustable by results confirm the effectiveness of the proposed

关键词： Disturbance observer Guidance Input saturation Mars atmospheric entry Robustness

Simultaneous state and actuator fault estimation for satellite attitude control systems

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Chinese Journal of Aeronautics 2016年第3期29卷 714-721页

作者： Cheng Yao Wang Rixin Xu Minqiang Li Yuqing Deep space exploration Research center Harbin Institute of Technology

In this paper, a new nonlinear augmented observer is proposed and applied to satellite attitude control systems. The observer can estimate system state and actuator fault simultaneously. It can enhance the performances of rapidly-varying faults estimation. Only original system matrices are adopted in the parameter design. The considered faults can be unbounded, and the proposed augmented observer can estimate a large class of faults. Systems without disturbances and the fault whose finite times derivatives are zero piecewise are initially considered, followed by a discussion of a general situation where the system is subject to disturbances and the finite times derivatives of the faults are not null but bounded. For the considered nonlinear system, convergence conditions of the observer are provided and the stability analysis is performed using Lyapunov direct method. Then a feasible algorithm is explored to compute the observer parameters using linear matrix inequalities （LMIs）. Finally, the effectiveness of the proposed approach is illustrated by considering an example of a closed-loop satellite attitude control system. The mance in estimating states and actuator faults. It also successfully. simulation results show satisfactory perfor- shows that multiple faults can be estimated

关键词： Actuator fault estimation Augmented state observer Fault diagnosis Lipschitz nonlinear systemSatellite attitude controlsystem

Groove formation on Phobos from reimpacting orbital ejecta of the Stickney crater

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Earth and Planetary Physics 2022年第3期6卷 294-303页

作者： XiangYu Xi Min Ding MengHua Zhu State Key Laboratory of lunar and Planetary Sciences Macao University of Science and TechnologyMacaoChina China National space Administration Macao Center for Space Exploration and ScienceMacaoChina

Numerous linear grooves have long been recognized as covering the surface of Phobos, but the mechanisms of their formation are still unclear. One possible mechanism is related to the largest crater on Phobos, the Stickney crater, whose impact ejecta may slide,roll, bounce, and engrave groove-like features on Phobos. When the launch velocity is higher than the escape velocity, the impact ejecta can escape Phobos. A portion of these high-velocity ejecta are dragged by the gravitational force of Mars, fall back, and reimpact *** this research, we numerically test the hypothesis that the orbital ejecta of the Stickney crater that reimpact Phobos could be responsible for a particular subset of the observed grooves on Phobos. We adopt impact hydrocode i SALE-2 D(impact-Simplified Arbitrary Lagrangian Eulerian, two-dimensional) to simulate the formation of the Stickney crater and track its impact ejecta, with a focus on orbital ejecta with launch velocities greater than the escape velocity of Phobos. The launch velocity distribution of the ejecta particles is then used to calculate their trajectories in space and determine their fates. For orbital ejecta reimpacting Phobos, we then apply the sliding boulder model to calculate the ejecta paths, which are compared with the observed groove distribution and length to search for causal relationships. Our ejecta trajectory calculations suggest that only ~1% of the orbital ejecta from the Stickney crater can reimpact Phobos. Applying the sliding boulder model, we predict ejecta sliding paths of 9-20 km in a westward direction to the east of the zone of avoidance, closely matching the observed grooves in that region. The best-fit model assumes an ejecta radius of ~150 m and a speed restitution coefficient of 0.3, consistent with the expected ejecta and regolith properties. Our calculations thus suggest the groove class located to the east of the zone of avoidance may have been caused by reimpact orbital ejecta from the Stick

关键词： Phobos groove formation Stickney crater reimpact ejecta

Pre-LOI trajectory maneuvers of the CHANG'E-2 libration point mission

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Science China(Information Sciences) 2012年第6期55卷 1249-1258页

作者： WU WeiRen 1,LIU Yong 2,3,LIU Lei 2,3,ZHOU JianLiang 3,TANG GeShi 2,3 & CHEN YongZhi 3 1 Chinese lunar exploration and space Project center,Beijing 100037,China 2 Science and Technology on Aerospace Flight Dynamics Laboratory,Beijing 100094,China 3 Beijing Aerospace Control center,Beijing 100094,China Chinese lunar exploration and space Project center Beijing China Science and Technology on Aerospace Flight Dynamics Laboratory Beijing China Beijing Aerospace Control center Beijing China

This paper addresses pre-LOI (before Lissajous orbit insertion) trajectory maneuvers for the libration point mission of CHANG'E-2,which is the first Chinese satellite to fly to the Sun-Earth L2 libration point and the first satellite ever to fly to the L2 point from lunar ***,a transfer trajectory for the mission is designed based on InterPlanetary Superhighway theory under the constraint of the remaining propellant,TT&C (telemetry,track and command) and sunlight *** effects of trajectory maneuver errors on the mission are also ***,based on the analysis results,the article investigates the trajectory maneuver schemes for the lunar escape and transfer trajectory maneuvers employing mathematical models and operational *** mission status based on our maneuver schemes is then presented,and the results of control operation and corresponding analysis are provided in ***,the future trajectory maneuver in the Lissajous orbit is *** to the analysis of the CHANG'E-2 TT&C data,the trajectory maneuver schemes proposed in the article work properly and efficiently.

关键词： CHANG’E-2 libration point trajectory maneuver escape trajectory transfer trajectory

The Present Situation And Future Development Of Chang'e program

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Aerospace China 2006年第3期7卷 15-17页

作者： Hao Xifan Zhou Jishi lunar exploration program center of China National space Administration

The first lunar orbiter of China＇s Chang＇e program will be launched in 2007. The lunar orbiting project, the first phase of Chang＇e program, includes five major engineering systems. Three engineering objectives and four scientific objectives will be realized during the first phase. This paper gives a brief introduction to the present situation and future development of Chang＇e program.

关键词：当前局势未来发展人造卫星中国