U. S. Navy in Space: Past, Present, and Future

The announcement last summer of the establishment of the U. S. Navy Space Command, and its subsequent activation at Dahlgren, Va., in October 1983, may have come as a surprise to some. This, however, was the latest of a series of actions taken by the Department of the Navy over the last several years to consolidate the Navy's space efforts. In fact, since the beginning of the Space Age, the Navy has been interested in space and involved in space-related activities. Its contributions in space science and technology have been significant. Driven by a realization that space assets are exceptionally well matched to its global mission, the Navy has become a major user of space. Primary areas of current activity include command, control, and communication and navigation and collection of environmental information. The Navy's operational use of space systems, the nature of the evolving Soviet threat (both air and space) directed in a large measure at U. S. naval targets, and the recent advances made in space technology, all argue for an increased level of Navy involvement in future Department of Defense space activities to secure Navy interests. As viewed by Navy decision-makers, this increased level of involvement will be selective in nature, emphasizing space research and development and operations that are considered vital to Navy interests.     

Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research

This review discusses the current status of supermassive black hole research, as seen from a purely observational standpoint. Since the early ‘90s, rapid technological advances, most notably the launch of the Hubble Space Telescope, the commissioning of the VLBA and improvements in near-infrared speckle imaging techniques, have not only given us incontrovertible proof of the existence of supermassive black holes, but have unveiled fundamental connections between the mass of the central singularity and the global properties of the host galaxy. It is thanks to these observations that we are now, for the first time, in a position to understand the origin, evolution and cosmic relevance of these fascinating objects.This revised version was published online in July 2005 with a corrected cover date.     

美军产品保障的过去、现在和未来

美军武器装备产品保障发展经历了从事后保障到综合后勤保障的发展演变过程,自20世纪90年代后期开始进入基于性能的后勤(PBL)保障阶段。近十多年来,为适应国防预算不断吃紧的压力以及新的作战环境和作战样式对产品保障的要求,缩减后勤规模,降低使用和保障费用,提高经济可承受性以及装备的战备完好性,美军出台了一系列新的政策、策略和指南,通过采办改革和产品保障转型,不断改进PBL,加速PBL的有效实施。目前,PBL已演变为美军下一代产品保障策略——基于性能的寿命周期产品保障,仍简称PBL。     

Integrated Avionics: Past, Present and Future [Society News & Information]

With the advent of integrated avionics in defense and commercial systems in the late 1980s, AESS began to recognize the importance of providing a technical and management sounding board for this emerging technology domain. The panel undertook a series of special studies of interest to the general avionics community. The first study was an assessment of the Air Force's modular avionics systems architecture (MASA) program     

航空航天质量标准的过去、现在和未来

航空航天行业的原设备制造商 (ＯＥＭ)和供应商们都十分关心有关质量体系要求的各种标准的繁衍。当这种情况已被所有行业都普遍关注时 ,我们仍有必要认真研究一下这个问题。　　多年来 ,航空航天领域的ＯＥＭ们采用一系列标准和法规 (如ＭＩＬ -Ｑ -985 8、ＭＩＬ -Ｉ-4 5 2 0 8、ＭＩＬ -Ｉ-1 5 35、ＮＡＴＯＡＱＡＰ -1和ＦＡＲ 2 1部等 ,还有一些公司的特殊要求 ) ,以满足客户的要求。这些要求被转换为公司的各种专用文件并作为对质量体系的要求提交给供应商 ,以供各制造商进行质量审核。这些大同小异的要求有时在各自的范围内具有一定的…     

The Radio Frequency Subsystem and Radio Science on the MESSENGER Mission

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Radio Frequency (RF) Telecommunications Subsystem is used to send commands to the spacecraft, transmit information on the state of the spacecraft and science-related observations, and assist in navigating the spacecraft to and in orbit about Mercury by providing precise observations of the spacecraft’s Doppler velocity and range in the line of sight to Earth. The RF signal is transmitted and received at X-band frequencies (7.2 GHz uplink, 8.4 GHz downlink) by the NASA Deep Space Network. The tracking data from MESSENGER will contribute significantly to achieving the mission’s geophysics objectives. The RF subsystem, as the radio science instrument, will help determine Mercury’s gravitational field and, in conjunction with the Mercury Laser Altimeter instrument, help determine the topography of the planet. Further analysis of the data will improve the knowledge of the planet’s orbital ephemeris and rotation state. The rotational state determination includes refined measurements of the obliquity and forced physical libration, which are necessary to characterize Mercury’s core state.     

发动机维护服务的现状与未来

航空发动机大修业务开始企稳,而且预计未来还将有所增加. 据MRO Prospector统计,目前在役的窄体飞机机队数量约是宽体飞机的3倍,2011年窄体飞机的发动机返厂维修量将会有大幅增加.     

海派张园:从过去到未来

素有海上第一名园之称的静安区张园,地处南京西路风貌保护区的核心区域,是清末民初老上海三大私家园林之一,是近代各式花园洋房和里弄建筑的博览园。今年1月末,张园地块保护性旧改征收正式生效,这也标志着这里一千多户居民将告别老房子,开启新生活。据相关部门介绍,未来张园地块将保留几乎全部历史建筑,进行修旧如故的保护改造。     

深空导航无线电干涉测量技术的发展历程和展望

结合世界各航天大国和组织所开展的深空探测活动和深空测控系统建设中,对无线电干涉测量技术的开发、应用以及深空导航技术试验验证情况,系统地梳理和总结了深空导航无线电干涉测量技术的发展历程,并通过该技术未来在国际上几个主要深空探测任务中的应用规划,分析了无线电干涉测量领域未来的发展方向.该领域技术的最新发展对我国深空测控网无线电干涉测量系统的后续建设也具有重要的借鉴意义.     

Studies of Comets in the Ultraviolet: The Past and the Future

The remote sensing of comets in the ultraviolet bandpass has been a valuable tool for studying the structure, composition, variability, and physical processes at work in cometary comae. By extension, these studies of comae have revealed key insights into the composition of cometary nuclei. Here we briefly review the ultraviolet studies of comets, and then take a look toward the future of such work as anticipated by the advent of several key new instruments. This revised version was published online in June 2006 with corrections to the Cover Date.     

未来军用频谱的管理和应用

无线电频谱是一项有限的自然资源，是全人类的共同财富，任何一个国家都不可忽略其他国家的存在，独自操纵它。军用频率的使用也不例外，同样受到国际频谱使用规则和程序的约束。对无线电频谱拥有足够的使用权是进行未来战争准备和高效战斗的决定因素之一，也是减少战争间接损失和避免不必要伤亡的重要因素，军用频谱管理正面临越来越多的挑战     

航空制造业无线射频识别技术应用进展

伴随着科技的进步和经济社会的快速发展,自动识别技术在人类社会发展中的作用变得越来越重要,已成为推动经济和社会发展不可或缺的力量.近年来,无线射频识别(Radio Frequency Identification,RFID)技术分外受人注目.     

航天大国的合作与角逐点评未来世界航天探索活动的发展趋势

在征服宇宙的漫漫征程中,财大气粗、技术实力雄厚的美国不乏令人眩目的各项计划;欧洲对开发太空资源同样梦寐以求,但其受巨额开支限制,只能推行以"实用太空"计划为首的策略;以俄罗斯、日本为代表的一些综合实力远不及美欧的国家,走的则是另一种适于自己的发展道路.未来太空资源的开发之争将主要在航天大户间展开.     

无线射频识别(RFID)技术标准化工作介绍

阐述了无限射频识别技术的基本概念、国内外相应的标准化组织及标准化动态、ISO/IEC的标准体系和相关标准的主要内容,反映了无限射频识别技术的发展趋势.     

无线电干涉测量在深空航天器导航中的应用

介绍了用于确定航天器相对于自然射电源或另一颗航天器角位置的几种无线电干涉测量技术及其在深空探测航天器导航中的应用。差分干涉测量通过对传播时延进行差分消除了大量公共误差,可以达到很高的测角精度,对深空航天器的导航具有重要意义。针对几种干涉测量技术中包含的相位整周模糊这一关键问题,介绍了当前国际上的几种解决方法。系统地分析了影响干涉测量的主要误差源,并对这一领域未来的发展趋势进行了展望。     

飞机环境控制系统的现状与未来

综述了飞机环境控制系统研究的发展与前景。通过对现有各种环控系统的优点与不足的讨论 ,提出了蒸汽循环制冷系统由于其高可靠性和使用了无污染制冷剂 ,有可能成为飞机环控系统的一个发展方向 ,而基于模糊理论和神经网络的微处理器控制方式的导入 ,将提高飞机环控系统的控制技术水平。     

月球与深空探测频率规划研究

介绍国际电（ITU）和空间频率协调组（SFGC）关于月球与深空探测频率使用的一些规定和建议,研究国外月球与深空探测频率使用规划和发展趋势,探讨我国月球与深空探测频率使用需求,提出我国月球与深空探测频率建议和发展方向。     

Future Commercial Directions in Environmental Remote Sensing from Space

Potential developments are considered for commercial applications of environmental remote sensing from space. The key areas affecting the possible growth of commercial markets that apply the sciences of meteorology, oceanography, and hydrology are discussed and projections made for 1985-2000. These areas include technology developments, markets, fiscal issues, political/legal/regulatory issues, and others. The growth will not be primarily limited by technology, but important uncertainties exist in the fiscal, political, and market development areas. With proper definition of government and commercial roles, both sectors can continue to maintain U. S. leadership in this area.