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Marius Hills is a volcanic plateau on the nearside of the Moon. It is of great interest for its high concentration of volcanic features, including domes, cones, ridges, and rilles. However, the morphological and chronological characteristics of this plateau were not well studied due to the low resolution of early mission data. This study describes the detailed morphology of the volcanic features using the latest high spatial resolution images of the Terrain Camera （TC） onboard Selene-1 （10 m/pix） and Narrow Angle Camera （NAC） onboard the Lunar Reconnaissance Orbiter （LRO） （0.5 m/pix）. We report here some new structures such as skylights and remnants of lava tubes. We have divided spectrally homogenous areas with Clementine UVVIS data and did crater size frequency distribution （CSFD） measurements with Lunar Orbiter （LO） IV and TC images in every spectral unit. We first report absolute model ages of 1.10 Ga for Marius basalt 1, 1.49 Ga for Fiamsteed basalt, and 1.46 Ga for Schiaparelli Basalt. In addition, we h

The lunar probe often has some remaining fuel on completing the predefined Moon exploration mission and may carry out some additional tasks from the Moon orbit using the fuel. The possibility for the lunar probe to escape from the Moon and the Earth is analyzed. Design and optimization of the trajectory from the Moon orbit to the Near Earth Asteroids （NEAs） using the spacecraft＇s residual fuel is studied. At first, the semi-major axis, inclinations and the phase relations with the Earth of all the numbered NEAs are investigated to preliminarily select the possible targets. Based on the Sun-centered two-body problem, the launch window and the asteroid candidates are determined by calculating the minimum delta-v for two-impulse rendezvous mission and one-impulse flyby mission, respectively. For a precise designed trajectory, a full ephemeris dynamical model, which includes gravities of the Sun, the planets and the Moon, is adopted by reading the JPL ephemeris. The departure time, arrival time, burning time duration and thrust angles are set as variables to be designed and optimized. The optimization problem is solved via the Particle Swarm Optimization （PSO） algorithm. Moreover, two feasible NEA flyby missions are presented.

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 orbit.First,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 conditions.The effects of trajectory maneuver errors on the mission are also analyzed.Second,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 strategies.The mission status based on our maneuver schemes is then presented,and the results of control operation and corresponding analysis are provided in detail.Finally,the future trajectory maneuver in the Lissajous orbit is discussed.According to the analysis of the CHANG＇E-2 TT＆C data,the trajectory maneuver schemes proposed in the article work properly and efficiently.

月球重力场可用来研究月球演化过程和内部结构,是影响绕月卫星精密定轨的重要因素。基于GRAIL任务数据解算的GL0660B重力场模型,极大提高了月球重力场空间频谱信号的强度和范围。本文首先通过计算相应重力场的阶方差和地形相关性分析,对GL0660B模型进行了精度分析;其次,利用GL0660B模型和其他几个月球重力场模型进行比较,对月球重力场的特征进行了分析;然后通过绘制GL0660B模型和LP150Q模型在月球外部不同高度处的重力异常图,分析比较了月球重力场模型在不同高度上所反映的月球重力场的特征和差异;最后,利用GEODYN软件模拟计算了不同高度卫星的轨道变化。可以看出绕月卫星离心率随时间的变化,以及周期性变化趋势,而且不同高度卫星轨道处质量瘤的摄动影响不同,远月点、近月点和偏心率的变化也存在差异。

本文以我国即将发射的＂嫦娥五号＂＂嫦娥四号＂任务为背景,系统性地讨论了行星探测器精密定轨和重力场解算的原理、技术和具体算法,完善月球卫星精密定轨的各个细节,开发了一套具有自主知识产权的月球探测器精密定轨与重力场解算软件系统LUGREAS;提出了基于月球着陆器-轨道器的四程中继跟踪测量模式,定量计算了该跟踪模式对轨道器精密定轨和着陆器精密定位的贡献。

在传统星座自主定轨中,SST（satellite to satellite tracking）可以同时提供轨道的大小、形状和星座相对方位信息,但不能确定星座的绝对定向。针对这一亏秩问题,联合圆型限制性三体模型CRTBP（circle restricted three bodyproblem）下的一种平动点周期轨道-Halo轨道飞行器,与二体问题轨道卫星组成扩展星座。利用两种力模型的特性差异,可以去除星座系统上的相关性,避免星座的整体旋转,从而确定星座的全部轨道状态参量。分析Halo轨道的力模型及性态特点,从系数矩阵的相关性角度讨论引进Halo轨道对定轨法矩阵正定性的改善作用,利用地月系L1平动点附近的Halo轨道与月球低轨卫星（LMO）的星间链路,在理想CRTBP框架下进行自主定轨仿真。初步验证了LMO-Halo星座定轨可行性,为开展附加平动点轨道的星座SST定轨提供了参考依据。