拉开外空采矿竞赛的序幕？-美国行星采矿立法的法律政策分析

2015年11月25日,美国通过了《2015外空资源探索和利用法》,为私人实体进行月球及行星采矿提供了法律依据,赋予了私人实体对其开采的任何小行星资源或外空资源的各项权利,包括占有、拥有、运输、使用和出售的权利。这一规定引起了国际社会的热议。在该法案起草、论证到通过的1年多时间里,国际空间法学界对其进行了多次讨论,以质疑声居多。虽然国际法没有明确的禁止规定,但大多数学者仍认为外空属于“公有区域”,任何国家和个人不得主张对外空包括其自然资源的所有权。     

美国商业对地观测数据政策发展综述

商业化是美国国家航天政策中非常重要的一部分,对地观测商业化更是整个商业航天领域非常重要的部分,有着广阔的前景和广泛的应用。经过数次重大修改和不断的补充完善,美国商业对地观测数据政策已形成较为成熟的体系,为美国对地观测卫星应用和产业化发展提供了强有力的支持。     

鹿死谁手-东西方主战坦克比较

在“沙漠风暴作战”（Operation Desert Storm）和“自由伊拉克作战”（Operation larqi Freedom）中，美军所使用的M1系列主战坦克可说是所向披靡，在战场上打遍天下无敌手。至于作为对手的俄制T72坦克则是一败涂地，根本毫无招架之力。从战场上的成绩来看，M1系列主战坦克的确是大获全胜，让对手完全报销。     

美国的战斧巡航导弹

3月19日,美英法三国开始对利比亚实行军事打击。在当天进行的空袭行动中,部署在地中海的美军和英军军舰与潜艇就向利比亚首都的黎波里郊区和东部城市米苏拉塔等地发射了110多枚战斧巡航导弹,袭击了20多处防空设施和民事目标。在随后的几天里,每天又都发射了一批这种导弹。截止到4月1日,美军共发射了221枚、英军共发射了7枚战斧巡航导弹。那么,战斧巡航导弹究竞     

美国成功发射移动用户目标系统-4

2015年9月2日,美国成功发射移动用户目标系统-4(MUOS-4)卫星,这是美国在2015年发射的第2颗MUOS卫星。目前,这一5星星座已完成4星发射,构成了海军所谓的"初始星座",基本实现了全球覆盖。经过数月在轨测试之后,MUOS-4卫星将投入使用。配合地面站的建设和大系统联合测试,整个系统将于2017年实现"全面运行能力"(FOC)。届时,MUOS卫星的数字化载荷将为战术部队卫星通信能力带来质的飞跃。     

美国,西德和意大利的真空计量

近几年来,我们先后访问了美国NBS、西德PTB和意大利IMGC,他们都是国际上重要的计量学研究中心。本文将着重介绍他们的真空计量工作,由此也可以了解到国际真空计量学研究的一些动向和趋势。NBS超声干涉仪水银压力计,为国际最高水平。PTB的超高真空计量标准——分子束法(10~(-10)P_a)为国际最好水平。IMGC建有从10~5～10~(-5)Pa区间的各种标准。     

美国内部争论:航天部队是否独立成军

正2017年6月,由众议员罗杰斯和库珀领导的众议院军事战略力量小组委员会提出了一项法律草案,决定设立太空部队(类似海军陆战队),将太空军事行动与空军其他军事行动分开。罗杰斯和库珀希望尽快促成此事。如果这一草案成为法律,空军将在2019年1月1日之前建立新的军种,司令官将在国防部参谋长联席会议上得到席位,并直接向空军部长汇报。2017年3月以来,美国空军部长希瑟·威尔逊和空军参谋长大卫·古德芬已在参议院拨款委员会、众议院     

美国用探空火箭发射学生卫星

<正>美国东部时间2010年3月27日10点09分,美国航宇局(NASA)从沃洛普斯飞行基地发射了一枚用于试验的探空火箭。火箭进入亚轨道之后,成功释放了两颗由学生建造的立方体卫星。     

U.S. operational space program for climate observations

Satellites provide two important characteristics to earth climate studies not available from other, conventional sources: (1) full global coverage, and (2) consistency within the data set. This latter arises from the fact that the satellite data are usually derived from one instrument (or at least from a small number) whereas other sources involve large numbers of separate instruments and hence exhibit a substantial standard deviation. Satellite data, of course, are more subject to bias and must therefore be carefully validated, usually via ground truth.The ISCCP and ISLSCP are examples of the increasing reliance on satellite data for climate studies. In addition to the multispectral images, quantitative products of importance are: (1) atmospheric temperature structure, (2) snow cover, (3) precipitation, (4) vegetation index, (5) maximum/minimum temperature, (6) insolation, and (7) earth radiation balance. The U.S. civil space program is presently committed to its current geostationary (GOES) and polar (NOAA) programs through this decade and to continue both programs into the next decade with spacecraft carrying improved and augmented instrumentation. GOES VISSR Atmospheric Sounder (VAS) data, presently in research status and available only for special observation periods, will become available operationally in 1987 from the current spacecraft series. GOES-Next will provide additional spectral channels, simultaneous imaging, atmospheric soundings, and possibly increased resolution starting in 1990. The NOAA follow-on spacecraft, in the same time frame, is expected to provide additional spectral channels, improved passive microwave radiometry, and possibly increased spatial resolution. The Landsat program is expected to be continued by a commercial operator following the useful life of Landsat-5. All three follow-on programs are presently at various stages of definition and procurement. Final definition may not be completed until late in 1984. However, their status as of the time of this presentation will be reviewed in detail.     

U.S. planetary protection program: Implementation highlights

The implementation of planetary protection in the United States space program has reflected the trend in policy from an absolute to a probabilistic prohibition of the contamination of the celestial bodies of the solar system. The early emphasis on spacecraft sterilization (e.g. Ranger) was replaced by the imposition of contamination control procedures on later missions such as Pioneer, Viking, and Voyager. Similarly, analytical and laboratory techniques were developed to demonstrate compliance with probabilistic requirements. Microbial burden reduction methods that are not hazardous for spacecraft reliability supplanted the abstract concept of sterilization. The United States implementation of planetary protection has been completely successful. In an exploration program that has included Mercury, Venus, Mars, the Jovian system, and the Saturnian system, there have been no accidental impacts or detection of false positives (terrestrial microbes). Further, the contamination control and microbial burden procedures have proved beneficial to spacecraft systems and on-board science instruments. We review in this paper the implementation of planetary protection procedures by the Pioneer (10 and 11), Viking and Voyager projects.     

美国载人太空探索的艰难进程

正奥巴马政府中止了重返月球的载人航天计划以后,其提出的载人登火星构想给美国载人航天出了一个大难题。虽然咬住了低地球轨道以远的大方向未曾放松,但遥远的火星如何去,美国经历了关于未来载人航天的争论和艰难抉择。现在,以载人登火星为背景的小行星探索计划又遇到了新问题—2016年4月提出的"太空复兴"法案对该计划提出了质疑,特朗普政府的决策仍很艰难。1"灵活性途径"显示美国低地球轨道以远载人航天的无奈过渡     

美国GPS系统及其国际合作进展

当前世界各卫星导航系统竞相发展。为适应新的发展局面,全球导航卫星系统(GNSS)供应商纷纷利用各类多双边平台开展国际协调,围绕卫星导航领域的国际合作不断加深。美国GPS自20世纪90年代建成以来,一方面不断优化星座结构,进行系统升级,保持技术领先;另一方面也针对国际形势不断调整对外合作战略,加强与其他系统间的对话与交流,通过各类多双边平台积极扩大国际合作范围,从而维护其在卫星导航领域的主导地位。     

美国“天基太空监视”系统卫星投入运行

据美国空军太空司令部网站2011年3月14日报道,经过5个多月的在轨试验与评估,美国空军最近已把首颗"天基太空监视"系统卫星的控制权移交给了位于施里弗空军基地的第50作战大队第1太空作战中队。它具有里程碑的意义,是美国为提高空间目标和活动监视能力,完全掌握空间战场态势研制的天军武器系统。该卫星投入正式运行后,能按照     

梦想从这里开始——2010年赴美太空营训练夏令营

<正>2010年8月10日～23日,由中国宇航学会组织承办的赴美国太空营训练夏令营在美国举行,来自北京、上海、西安、苏州、无锡的56位师生参加了本次活动。在阿拉巴马太空营训练中心,营员们按年龄分成4组,由教官带领分别进     

U.S. FGGE special data sets and special effort

Three topics are considered, all resulting from the desire to maximize the utilization and overall quality of the FGGE data sets.First, the production of Level III-b oceanographic and meteorological analyses in the FGGE format has been undertaken by the Fleet Numerical Oceanography Center. The oceanographic data, in particular the sub-surface oceanographic data, is a unique addition to the FGGE data base.Next, the FGGE Level II-b data set is the most comprehensive set of synoptic-scale meteorological data ever assembled to date. Under development is a program aimed at compacting and restructuring the Level II-b data according to observing systems, so that the data will be more readily usable and more economical for users interested in smaller and/or different portions of the total FGGE Level II-b data set.Lastly, as a result of the United States pre-FGGE Data Systems Tests, a need was indicated for a special effort to edit and enhance satellite soundings and cloud motion wind data during FGGE. A formal program to carry out such an effort has been established jointly by NASA, NOAA, and the University of Wisconsin.     

美国商业航天发展分析

当前,美国商业航天正处于快速发展的新阶段,其业务范围正从传统的商业卫星发射、商业卫星应用,扩展到政府从私营企业购买商业发射服务和发展商业载人航天飞行等领域,以美国太空探索技术公司（SpaceX）、轨道科学公司（OSC,现更名为轨道-阿连特技术系统公司,简称轨道-ATK公司）、天空盒子成像公司（Skybox Imaging）等为代表的新兴航天企业快速崛起,以谷歌公司（Google）为代表的互联网巨头也开始进军航天。商业航天发展的新思维、新理念与新模式对传统航天产业产生了巨大冲击和影响。     

美国未来太空政策的 颠覆与维持之斗

1 唐纳德·特朗普——颠覆现有太空政策唐纳德·特朗普曾一度表达对现有太空政策的不满,认为就像是第三世界国家.他提出美国需要一个全新的太空政策,需要将公共任务、商业手段,以及快速及时地解决现实威胁和把握现实机会三者结合起来.唐纳德·特朗普要求其竞选政策顾问罗伯特·沃克,为竞选活动提出一个有远见的、颠覆性的、合作性的、具有弹性的、具有实质性改变的太空政策.     

美国太空高新装备的发展与前景展望

正太空是关系国家战略安全的高边疆。早在20世纪60年代初期,时任美国总统肯尼迪就公开宣称:谁能控制太空,谁就能控制地球。今天,太空的军事、政治、民用、商业价值愈发凸显,主要航天强国均大力发展空间装备,谋求更好地实现进入太空、利用太空、控制太空的目标。     

美国“扩展空间传感器体系结构”研发及应用分析

正用于空间监视的传感器水平十分重要,因其决定着所获取空间态势感知数据的多少。空间态势感知数据的传输与共享技术在空间作战中也同样扮演着重要角色,受限时也会导致数据无法充分利用。由于空间资产在国家安全中的重要性日益提升,美国对空间态势感知越来越重视。为了保护美国的空间资产免于自然灾害和人为     

Estimating irrigation water use and withdrawal of ground water on the High Plains,U.S.A.

In four decades following the Dust Bowl days of the 1930's, extensive areas of dry farming and rangeland on the semi-arid U.S. High Plains were transformed into a vast region of irrigated oases, producing meat and grain for much of the world. The agricultural economy has experienced such rapid growth in part because of the availability of ground water and because of development of new irrigation technology to use that water for agriculture. However, more water is being used than is being replaced. To estimate both the volume of water withdrawn and the regional scope of the problem a technique has been developed that combines multispectral data from Earth-orbiting satellite with known pumpage data for the same growing season. The location and extent of irrigated cropland—some with different crops watered at different times—is inventoried using computer-assisted analysis of the data from Landsat. The amount of water used is estimated by multiplying and summing surface area of irrigated agriculture and the average measured pumpage from sampled sites. Published findings to date are cited in the Selected References. All suggest transferability of a promising technology to the study of land transformation processes elsewhere.