嫦娥一号卫星数据高可靠性保护设计

针对我国第一个月球探测器的特点,对星载网络数据保护做了专门的设计。文章着重介绍了嫦蛾一号卫星星载数据高可靠性保护的设计方案与具体实现情况。     

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...     

8m×6m 风洞测控处系统

８ｍ×６ｍ风洞测控处系统以ＶＡＸ－Ⅱ为上位机,通过ＱＢＵＳ总线连接数据采集、速压控制、模型姿态角控制和数据实时分析与显示等四个子系统,完成对风洞试验的管理和数据测量与分析及显示。本文介绍了该系统的构成、主要功能和技术指标等。     

高超声速轴对称模型密度场的激光全息干涉测量

激光全息干涉技术在 2 0 0m自由飞弹道靶的初步应用中 ,对高速和高超声速的轴对称模型周围气流密度场定量测量进行了初步探索。给出了 M =2 .2的弹头和M =2 .45、Φ =2 0mm的球标模以及M =9.35的钝锥模型的全息干涉图和处理结果 ,同时与钝锥模型的理论数值计算结果进行了比较 ,首次在弹道靶上获得了流场密度的定量结果。     

试车台氧化剂系统增压能力影响因素分析

试车台进行改造后,管路和容器参数都发生了变化,试车过程中需在要求时间内完成发动机氧化剂入口压力从前稳段升压至过载段。首次试车过程中由于贮箱增压计算出现误差,导致氧化剂升压过程中增压阀门多次动作。为避免升压过程中增压阀门的多次动作,获得试车台的实际增压能力,对其影响因素及试车数据进行了分析,修正了调整计算过程。试验结果表明:调整计算正确,改进措施有效,满足了试验任务要求。     

In-orbit assessment of laser retro-reflector efficiency onboard high orbiting satellites

The navigation and geodetic satellites that orbit the Earth at altitudes of approximately 20,000 km are tracked routinely by many of the Satellite Laser Ranging (SLR) stations of the International Laser Ranging Service (ILRS). In order to meet increasing demands on SLR stations for daytime and nighttime observations, any new mission needs to ensure a strong return signal so that the target is easily acquirable. The ILRS has therefore set a minimum effective cross-section of 100 million square metres for the on-board laser retro-reflector arrays (LRAs) and further recommends the use of ‘uncoated’ cubes in the arrays. Given the large number of GNSS satellites that are currently supported by SLR, it is informative to make an assessment of the relative efficiencies of the various LRAs employed. This paper uses the laser ranging observations themselves to deduce and then compare the efficiencies of the LRAs on the COMPASS-M1 navigation satellite, two satellites from the GPS and three from the GLONASS constellations, the two GIOVE test satellites from the upcoming Galileo constellation, the two Etalon geodetic spheres and the geosynchronous communications test satellite, ETS-8. All the LRAs on this set of satellites employ back-coated retro-reflector cubes, except those on the COMPASS-M1 and ETS-8 vehicles which are uncoated. A measure of return signal strength, and thus of LRA-efficiency, is calculated using the laser-range full-rate data archive from 2007 to 2010, scaled to remove the effects of variations in satellite range, atmospheric attenuation and retro-reflector target total surface area. Observations from five SLR stations are used in this study; they are Herstmonceux (UK), Yarragadee (Australia), Monument Peak and McDonald (USA) and Wettzell (Germany). Careful consideration is given to the treatment of the observations from each station in order to take account of local working practices and system upgrades. The results show that the uncoated retro-reflector cubes offer significant improvements in efficiency.     

飞行管理系统下降路径构建及应用研究

在飞行管理系统下降设计中，通过下降路径的构建可为接近目的机场提供一个垂直轨迹，使飞机遵守终端区各种限制要求，从而精确控制下降路径，满足安全性要求。本文分析了下降路径的定义及其在典型机型中的构建方法，给出了下降路径的描述方法及实现途径，并对具体机型中的应用做了简要介绍。     

LabWindows/CVI环境下调用Word文档的实现方法

目的介绍一种在Labwindows/CVI环境下调用Word的实现方法;方法结合具体的实例,实现对Word文档的调用;结果该方法可以按照规定的格式自动生成Word文档;结论提高了软件的效率和自动化程度。     

Method of virtual trajectories for the design of gravity assisted missions

A method of virtual trajectories is proposed for the design of multiple gravity assist trajectories. The method comprises two principal stages. First, for a chosen planetary sequence, a database of virtual trajectories is tabulated. Then the database screening and refinement are performed. The design of trajectory to Jupiter is presented.     

试验数据管理系统的需求与实现

现在的工程试验产生大量的试验数据,而这些试验数据在储存和使用中存在着大量的问题。试验数据管理系统(TDM)通过梳理和优化试验流程,可以提高试验数据的利用率。