International cooperation and competition in civilian space activities

This article considers how the USA can best maintain its commercial and governmental competitiveness in space, while facilitating private investment and international marketing, and at the same time keeping up significant cooperation with other nations. The current state of US civilian space activities in each of these areas is summarized, and several alternative solutions are presented. The article concludes that strengthening US competition with other space-capable nations, and improving US ability to cooperate effectively, will require careful coordination of the activities of federal agencies with each other and with the private sector.     

Arms control and disarmament in space: the rough road to Vienna 1984: Part I

This article examines the international legal and diplomatic questions relating to arms control and disarmament, focusing on space-based activities. These relate importantly to the development of anti-satellite satellites (ASATs) and ballistic missile defence systems (BMDs). Part I of the article examines the goal of ‘peaceful uses’ of outer space as elaborated in national policies and in international fora, the debate that has has taken place at the international level over the meaning and definition of peaceful purposes, legal manoeuvres, particularly in the UN, and US responses, and recent Soviet initiatives relating to space militarization. Part II will appear in the next issue, and will consider the US Presidential-Congressional dialogue on these questions and recent Presidential initiatives.     

基于ICCD的空间微光成像系统成像性能研究

研究基于像增强型CCD（ICCD）的空间高分辨率微光成像系统的成像性能。通过理论推导及数学仿真的方法，对系统在微光条件下的能量传递、极限分辨力、信噪比以及调制传递函数进行分析计算。研究表明，系统在黎明照度条件下具有较好探测能力，通过对ICCD器件制冷可以有效提高系统信噪比，实现满月照度的探测成像。     

推进剂稳态燃速最优化辨识

考虑侵蚀燃烧对推进剂稳态燃速的影响,将推进剂稳态燃速模型参数辨识问题转化为非线性规划问题求解。采用Powell方法和并行遗传算法组成的混合优化方法,提高了非线性规划问题求解的效率和质量,得到了推进剂稳态燃速模型参数的全局最优辨识值。通过对设计空间的可视化进行优化收敛过程的参数分析,近似得到侵蚀燃烧模型参数的不确定性区间。     

行星际空间环境对探测器可靠性影响分析

空间环境是影响航天器可靠性的重要因素。与地球轨道航天器相比,行星际探测任务可能会遭受更加恶劣的空间环境,例如极端温度环境,辐射环境,腐蚀性大气环境、宇宙尘等,再加上行星际任务寿命长,采用先进的器件和材料,空间环境对行星际探测器的可靠性构成严重的威胁,直接关系到探测目标能否实现。因此考虑空间环境对行星际探测器的影响,开展相关的预先研究无论是对于制定行星际空间探测计划,还是搭载仪器的设计都具有非常重要的意义。文章分析了极端温度、辐射环境和行星表面综合环境对探测器的影响,并对开展相关研究提出了建议。     

一种新的导航星选取算法研究

在导航星表的建立过程中，由于恒星的数量太多，往往要进行筛选，通常这种选择复杂费时，而结果往往并不是最优的。本文引入了动态星等阈值分布函数，将传统星等阈值过滤算法中的静态阈值用动态星等阈值代替，建立了一种新的动态星等阈值过滤选择模式。而基于统计学习理论的支持向量机方法为求解高维非线性动态星等阈值分布函数提供了新的途径。本文讨论了这种基于支持向量机的导航星自动选择算法——回归选取算法。实验表明，用该算法所选取的导航星表，导航星数量少、分布均匀性好。同时它还能适应多种任务的导航星选取要求，具有很强的通用性。     

基于波形综合的雷达目标识别的自相关法

讨论雷达反隐身技术中的目标识别方法。重点介绍基于自然频率的波形综合雷达目标识别方法。针对实际雷达目标均被噪声污染 ,提出一种抗干扰能力强的自相关函数算法 ,给出该算法的实现步骤 ,进行计算机仿真试验 ,仿真结果表明 ,所提出的雷达目标识别方法有效。     

地球静止轨道空间碎片的处置

介绍了国际机构间碎片协调委员会提出的关于地球静止轨道（GEO）空间碎片问题的研究结果和碎片处置的建议，主要内容包括：GEO与GEO环的概念、EGO上物体现状，EGO空间碎片处置的基本原则和8条具体处置措施建议。该建议已于2000年2月提交联合国和平利用外层空间委员会科技小组委员会第37届会议。     

利用条形码测量电荷耦合成像系统的调制传递函数的方法

本文介绍了一种利用条型码来测量电荷耦合器件（CCD）在成像系统装置的调制传递函数的测量方法。同时分析了减少误差的方法，并给出了理论和实验数据。     

Cost Engineering – The new paradigm for space launch vehicle design

The paper describes the basic definition and application of 'Cost Engineering' which means to design a vehicle system for minimum development cost and/or for minimum operations cost. This is important now and for the future since space transportation has become primarily a commercial business in contrast to the past where it has been mainly a subject of military power and national prestige. Several examples are presented for minimum-cost space launch vehicle configurations, such as increasing vehicle size and/or the use of less efficient rocket engines in order to reduce development and operations cost. Further a cost comparison is presented on single-stage (SSTO)-vehicles vs. two-stage launchers which shows that SSTOs have lower development and operations cost although they are larger, respectively have a higher lift-off mass than two-stage vehicles with the same performance. The design of a space tourism-dedicated launch vehicle is an extreme challenge for a cost-engineered vehicle design in order to achieve cost per seat not higher than $50,000. Finally an outlook is presented on the different options for manned Earth-to-Moon transportation modes and vehicles – another most important application of 'cost engineering', taking into account the large cost of such a future venture.