超低轨道卫星应用离子电推进技术方案

低地球轨道大气环境对诸如科学探测和对地观测卫星的阻尼作用十分明显,而且阻尼随太阳和地磁活动以及昼夜、季节交替变化范围宽.为了保证卫星轨道精度或飞行状态满足任务要求,需要利用推进系统对卫星受到的阻尼进行实时或间歇式补偿以实现轨道或飞行状态的保持.针对轨道高度220～268 km的无拖曳飞行和轨道维持应用,基于卫星轨道阻尼...     

双自旋通信卫星姿态的选择方法

给出一种选择双自旋通信卫星在任意轨道飞行时最佳通信姿态的计算方法。根据测得的轨道平根数及姿态值,应用微机可对卫星轨道参数、星下点轨迹、地面站跟踪条件、姿态测量参数、卫星的太阳角、对应于各测控站的卫星测控天线增益、对应于各通信站的通信天线增益和波束中心地面轨迹进行快速计算,给出飞行试验需要的全部卫星飞行参数。根据飞行试验中对卫星姿态选择的附加限制,可以选择出最佳通信姿态,保证获得最长的通信时间。     

卫星编队飞行动力学仿真及其应用

由若干颗小卫星编队飞行组成一个虚拟卫星,其功能相当或超过一颗大卫星,这将开拓小卫星一个完全崭新的应用领域。文章首先研究轨道动力学,系统地研究编队飞行三种动力学模型,其次进行定位卫星和区域导航系统两个实例数学仿真,分析研究各种数学模型的精度和它们的应用场合。     

椭圆轨迹编队飞行轨道分析

国际航天界在探讨小卫星的应用过程中产生了8虚拟卫星9的新概念2这种虚拟卫星是由若干颗按一定的队形飞行的小卫星构成:这种编队飞行的卫星星群的轨道设计;轨道演变及控制是一个重要的研究课题:文章针对椭圆轨迹的编队飞行2直接利用轨道的分析理论研究了轨道的特征;轨道摄动的影响以及轨道控制方法和所需的速度增量:     

纳卫星热系统的在轨动态特性分析与建模

纳卫星热系统是在复杂空间热环境下实现纳卫星被动热控制任务的基本技术途径,对其进行在轨动态特性分析与建模对纳卫星的热控方法与效果研究及评价具有重要意义.通过详尽的机理分析建立了描述纳卫星热系统在轨飞行过程中瞬态温度变化的3维非线性动态特性模型,阐述了与之配套的外热流分析与轨道运动计算方法,并以一太阳同步轨道纳卫星为例,对其飞行过程中的外热流变化、在轨温度变化响应等动态特性进行了详细的分析和讨论,为进一步深入研究纳卫星热控制、热管理理论及技术提供了简便的分析计算模型与方法.      

GEO卫星快速发射入轨定点控制方法

提出了一种GEO卫星快速发射入轨定点方法,运载火箭将卫星发射进入GTO轨道后,由上面级或卫星自身在48h内快速定点到GEO轨道任意指定定点位置。考虑时间、测控等约束,在选定变轨策略基础上,以燃料消耗最小为目标,优化给出了快速入轨定点标称轨迹。采用无奇异的春分点根数描述轨道运动,基于最小二乘法给出了航天器在有限推力条件下变轨的闭环显式制导方法,控制航天器沿标称轨迹飞行。仿真算例表明,采用该变轨策略、轨道优化设计方法和制导律,可以完成GEO卫星快速入轨定点控制。     

编队飞行卫星群构型保持及初始化

导出了基于相对轨道要素的编队飞行卫星群轨道相对运动控制的轨道机动方程；提出了编队飞行卫星群轨道相对运动控制的轨道机动控制策略，利用不同方向的脉冲控制相对运动的轨道参数，包括轨道平面内机动和轨道平面外机动控制。根据相对轨道要素的变轨机动控制，进行编队飞行卫星群构型的初始化。这样的构型初始化可以视作一次特殊的变轨机动控制，很容易实现编队飞行构型的初始化机动。     

备受青睐的火星探测——著名火星探测器一瞥

最先进的人造火星卫星 经过近7个月的飞行,当今世界最先进、最大的人造火星卫星--"火星勘测轨道器"于美国东部时间2006年3月10日进入火星轨道.开始于2002年的这次飞行任务耗资7.2亿美元,     

中国月球探测卫星飞行程序

我国月球探测卫星的飞行过程将主要分为三个阶段:(1) 调相轨道段:月球探测卫星与运载火箭分离后,将先围绕地球运行一段时间。通过三次近地点变轨,逐步抬高轨道的远地点。在第三次变轨后(11),卫星脱离地球轨道,进入奔向月球的地—月转移轨道。(2) 地—月转移轨道段:地—月转移轨道是一条复杂的曲线,卫星要飞行5～6天,其间根据轨道的具体参数进行1～2次中途修正(13,15),以保证卫星正确进入预定的月球轨道。(3) 环月轨道段:当卫星达到距月球200千米时,卫星进行减速制动(18),进入环绕月球南—北极运动的月球极轨道。此后经过两次近月点制动(20,2…     

苏联预警卫星的轨道与频率

说美国先驱者11号79年9月3日探测土星时受到苏联预警卫星无线电频率的干扰,中断传输信号45分钟。在苏联宇宙号卫星中,有些卫星的轨道参数与苏联闪电型通信卫星的轨道参数很相似,但又有所不同。通过对这些卫星轨道的分析,很清楚地看出,宇宙号中的这些卫星负有新的飞行使命,它们属于宇宙号中的预警卫星系列。     

深空卫星重力测量计划研究综述

地球卫星重力测量计划CHAMP(CHAllenging Minisatellite Payload)、GRACE(Gravity Recovery and Climate Experiment)、GOCE(Gravity field and steady-state Ocean Circulation Explorer)和月球卫星重力测量计划(Gravity Recovery and Interior Laboratory,GRAIL)的成功实施,以及下一代地球重力卫星(GRACE Follow-On)的即将发射昭示着我们将迎来一个前所未有的高精度和高空间分辨的深空卫星重力探测时代。围绕深空卫星重力测量的研究背景、必要性、可行性、卫星重力反演软件平台构建、轨道摄动和未来研究方向开展了研究论证。研究表明:深空卫星重力测量作为新世纪重力探测技术,在精化量体重力场、提高惯性导航精度、天体动力学、天体物理学和军事技术的研究,以及促进国民经济发展和提高社会效益等方面具有广泛的应用前景。     

椭圆轨道卫星空间任意位置悬停的方法

对任务星施加持续的控制加速度,使其在飞行过程中相对于目标卫星的空间位置保持不变,即实现任意位置悬停飞行。通过对任务星与目标星的相对运行分析和重力差异补偿分析,给出了在飞行过程中任务星相对于运行在椭圆轨道上的目标星实现任意位置悬停所需的径向、切向和法向控制加速度公式。最后对典型悬停飞行过程进行了动力学仿真,并对不同悬停飞行任务的能量消耗进行了对比分析,表明在一段时间内对任务星进行轨道悬停是可行的。     

Mission planning optimization of video satellite for ground multi-object staring imaging

This study investigates the emergency scheduling problem of ground multi-object staring imaging for a single video satellite. In the proposed mission scenario, the ground objects require a specified duration of staring imaging by the video satellite. The planning horizon is not long, i.e., it is usually shorter than one orbit period. A binary decision variable and the imaging order are used as the design variables, and the total observation revenue combined with the influence of the total attitude maneuvering time is regarded as the optimization objective. Based on the constraints of the observation time windows, satellite attitude adjustment time, and satellite maneuverability, a constraint satisfaction mission planning model is established for ground object staring imaging by a single video satellite. Further, a modified ant colony optimization algorithm with tabu lists (Tabu-ACO) is designed to solve this problem. The proposed algorithm can fully exploit the intelligence and local search ability of ACO. Based on full consideration of the mission characteristics, the design of the tabu lists can reduce the search range of ACO and improve the algorithm efficiency significantly. The simulation results show that the proposed algorithm outperforms the conventional algorithm in terms of optimization performance, and it can obtain satisfactory scheduling results for the mission planning problem.     

行星着陆自主导航与制导控制研究现状与趋势

行星着陆自主导航与制导控制技术是行星着陆过程的核心技术之一,关系到行星着陆任务的成败。本文基于未来火星和小天体着陆对自主导航与制导控制技术的发展需求,阐述了进一步开展自主导航与制导控制研究的必要性,围绕行星着陆过程环境特点,分析了自主导航与制导控制技术所遇到的挑战,随后概括了行星着陆自主导航与制导控制所涉及的关键技术,并综述了关键技术的研究现状。最后对我国未来行星着陆探测自主导航与制导控制技术的发展方向进行了展望。     

An introduction to the lunar and planetary science activities in Korea

Korea is planning a series of lunar space programs in 2020 starting with a lunar orbiter and a lander with a rover. Compared to other countries, Korea has a relatively brief history in space and planetary sciences. With the expected Korean missions on the near-term horizon and the relatively few Korean planetary scientists, Korea Institute of Geoscience and Mineral Resources (KIGAM) has established a new planetary research group focusing on development of prospective lunar instruments, analysis of the publicly available planetary data of the Moon, organizing nationwide planetary workshops, and initiating planetary educational programs with academic institutions. Korea has also initiated its own rocket development program, which could acquire a rocket-launch capability toward the Korean lunar mission. For the prospective Korea’s lunar science program, feasibility studies for some candidate science payloads have been started since 2010 for an orbiter and a lander. The concept design of each candidate instrument has been accomplished in 2012. It is expected that the development of science payloads may start by 2014 as Phase A. Not only developing hardware required for the lunar mission but also educational activities for young students are high priorities for Korea. The new plan of the Korean lunar mission can be successfully accomplished with international cooperative outreach programs in conjunction with internationally accessible planetary data system (PDS). This paper introduces the KIGAM’s international cooperative planetary research and educational programs and also summarizes other nationwide new developments for Korean lunar research projects at Kyung Hee University and Hanyang University.     

一种面向动态需求的多优先级天文观测卫星任务重规划方法

针对多优先级天文观测卫星任务动态规划问题，分析了高优先级任务动态插入以及未知事件中断原任务规划方案执行的情况，研究了原任务规划方案相应的动态规划问题.在关于SVOM （Space multi-band Variable Object Monitor）卫星任务规划系统的研究中，针对单星机遇目标任务重规划问题，提出一种基于滚动优化策略的任务重规划求解方案.在每个滚动周期内，优先安排高优先级动态到达任务，回滚处理原方案中受未知事件和高优先级机遇目标影响的任务，或者删除原方案中受影响的任务.目标函数综合考虑了全年卫星任务规划总时长和机遇目标的规划总时长.仿真验证结果表明，本文设计方法对于快速响应高优先级机遇目标以及提高服务质量具有一定意义.      

非圆轨道卫星实现共面悬停的方法

通过矢量控制,使任务卫星始终在目标卫星的轨道平面内飞行,同时保证"任务卫星-目标卫星-地心"的夹角和两颗卫星间的相对距离保持不变,从而实现共面悬停飞行。重点进行了任务卫星悬停飞行的动力学理论分析,推导了悬停飞行过程中任务卫星相对于目标卫星的径向和切向加速度需求,给出了开环控制方案,对不同悬停任务的能量需求进行了对比分析,最后对悬停飞行过程进行了动力学仿真。     

A neutral gas mass spectrometer to measure the chemical composition of the stratosphere

The Polar Balloon Atmospheric Composition Experiment (P-BACE) is a new generation of neutral gas mass spectrometer based on the time-of-flight principle. P-BACE is the scientific experiment on the Mars Environment Analog Platform (MEAP) flown successfully on a balloon mission in summer 2008. The MEAP mission was flown with a 334,000 m³ helium balloon in the stratosphere on a semicircular trajectory from northern Sweden around the North Pole to Canada using the summer northern hemispheric wind current. The atmospheric conditions at an atmospheric altitude of 35–40 km are remarkably similar to those on the surface of Mars and thus the balloon mission was an ideal testbed for our mass spectrometer P-BACE. Originally this instrument was designed for in situ measurements of the chemical composition of the Martian atmosphere.P-BACE has a unique mass range from 0 to 1000 amu/q with a mass resolution m/Δm (FWHM) > 1000, and the dynamic range is at least six orders of magnitude. During this experiment, the acquisition of one mass spectrum is a sum of 65,535 single spectra, recorded in a time frame of 66 s.The balloon mission lasted 5 days and had successfully demonstrated the functionality of the P-BACE instrument during flight conditions. We had recorded more than 4500 mass spectra. With little modifications, P-BACE can be used on a planetary mission for Mars, but for example also for Venus or Mercury, if placed on a satellite.     

Planetary environment protection ID no: F3.3-M.1.05 implications for the development of a network of surface stations on Mars.

The European Space Agency's studies of a Comet Nucleus Sample Return mission (ROSETTA) as its Planetary Cornerstone in its long-term programme 'Horizon 2000' and the Marsnet mission, a potential contribution of the Agency to an international network of surface stations on Mars, has revived the interest in the present state of Planetary Protection requirements. MARSNET was one of the four candidate missions selected in April 1991 for further Design Feasibility (Phase A) Studies. Furthermore, of all space agencies participating in planetary exploration activities only the United States National Aeronautics and Space Administration had a well established Planetary Protection Policy on Viking and other relevant planetary missions, whereas ESA is considering the feasibility and potential impact of a planetary protection policy on its Marsnet mission, within the framework of a tight budgetary envelope applicable to ESA's medium (M) class missions. This paper will discuss in general terms the impact of Planetary Protection measures, its implications for Marsnet and the issues arising from this for the implementation of the mission in ESA's scientific programme.     

Proposal for a multiple-asteroid-flyby mission with sample return

Asteroid exploration provides a new approach to study the formation of the solar system and the planetary evolution. Choosing a suitable target and designing of feasible profile for asteroid mission are challenging due to constraints such as scientific value and technical feasibility. This paper investigates a feasible mission scenario among the potential candidates of multiple flybys and sample return missions. First, a group of potential candidates are selected by considering the physical properties and accessibility of asteroids, for the sample return missions. Second, the feasible mission scenarios for multiple flybys and sample return missions to various spectral-type asteroids are investigated. We present the optimized design of preliminary interplanetary transfer trajectory for two kinds of missions. One is the single sample return mission to asteroids with various spectral types. The other is the multiple flybys and sample return mission to several asteroids. In order to find the optimal profiles, the planetary swing-by technique and Differential Evolution algorithm are used.