美国将建立私营航天港

美国私营工业界正在开发一次性运载器发射业务。为便于进行商业发射,在今后10年,美国很可能会建造若干个商业性服务设施——航天港。 由于联邦政府采取了鼓励政策,美国已有三个州为建造航天港做了基本准备工作。 美国运输部商业航天运输办公室(OCST)的一位经济学家说,美国在商业航天方面的竞争能力在很大程度上取决于私营航天港的建造。他说,外国竞争者     

美再次向俄购买空间核反应堆

美国白宫于1993年9月3日批准了国防部再从俄罗斯购买4个总价值2000万美元的黄玉2空间核反应堆的请求。早在1992年5月,美国曾以1300万美元的价格从俄购买了两个黄玉2反应堆并利用新墨西哥大学的设备进行无燃料试验。据美国防部官员说,美国购买黄玉2反应堆的目的是从中获得制造可为美国侦察卫星和其他航天器提供40千瓦电源系统所需的技术。美国在     

关于美国建设下一代航空运输系统的一些体会和感受

今年,笔者有幸参加了中美合作举办的中国民航高级管理培训班(EMDT)。在美国培训的5个月,使我有机会比较深入地了解美国民用航空运输业的现状和发展方向,在这里就美国建设下一代航空运输系     

这里的夜晚静悄悄——“联盟11”号返回舱悲剧

1971年,人类进入太空的第11个年头。 彼时,美国已经有5批航天员小组抵达月球并安全返回。一系列成功使得苏联在这一点上似乎难以望其项背。然而,阿波罗计划将于1972年终止,用余下的阿波罗登月硬件开发的天空实验室将成为美国的第一个空间站,作为去月球和火星的跳板。在美国的刺激下,苏联也将重心转向了“空间站”的建设……     

美苏战略核导弹的新趋向

当前,美苏两个超级大国在两个领域内展开了新一轮军备竞赛:一方面,是围绕“星球大战”计划,美国负责国际安全政策的助理国防部长理·珀尔1986年5月12日说,美国“星球大战”体系中的部分系统可能在九十年代部署;苏联国防部第一副部长、苏军总参谋长阿赫罗梅耶夫5月8日强调,美国部署打击性太空武器也夺取不了苏联的军事优势。另一方面,在地球上的战略进攻武器方面,也展开了激烈争夺,并且出现了如下几个引入注目的新动向。     

国外遥感卫星接收站布局及建设管理研究(上)

<正>一、引言据统计,全球具有一定规模的遥感卫星接收站有25个,其中18个是通过接收美国"陆地卫星"(Landsat)数据发展起来的。从数据服务能力和技术水平看,美国和欧洲接收站位居前两名,尤其是欧洲,不仅建设了完善的接收站网,而且积累了丰富的运行管理经验,这得益于欧洲国家实施的军民融合航天管理体制。美国的接收站分属不同机构,现行航天管理体制确定     

欧空局1993年航天活动安排

3月 用美国航天飞机将德国第二个空间实验室送入轨道; 用美国航天飞机将宇宙神2卫星送入轨道,进行大气层应用和科学试验。 4月 用阿里安火箭将 Astra 1C通信卫星送入轨道,同时搭载Arsene卫星; 用美国航天飞机回收欧空局的尤里卡平台。 5月 用阿里安火箭发射西     

近20年美国火星探测战略演化分析

2011年3月,美国发布的《2013～2022年行星科学的愿景与航程》将火星定为首要行星探测目标。历史上,火星就是美国探测次数最多的地外天体,进入21世纪第二个十年,火星探测将继续在美国整个太空探测活动中扮演重要角色。     

美国航天飞机的不同命运

12 400 000 000美元,这是美国研制航天飞机的费用:2 000 000 000美元,这是美国“奋进”号航天飞机的造价;500 000 000美元,这是美国维护和发射一次航天飞机的耗资;3 500个分系统,2 500 000多个零部件,这是一架美国航天飞机的构成,在飞行的过程中,航天飞机身上任何一个细节出现问题都可能将自己推向万劫不复的深渊。正是有如此高昂的造价和复杂程序导致的风险,所以航天飞机被人称作是“用黄金筑就的大蛋壳”。时至今日,美国当初建造的“大蛋壳”历经多年磨难,近况如何?它们的未来又在何方?——     

美国的空间探测盲区问题

美国目前还不能探测到苏联在深空中某些关键区域的活动。然而,苏联已有能力用其机动洲际弹道导弹进行航天发射,而且航天飞机即将运行,这将给美国空间探测带来更大的压力。 苏联的航天飞机即将运行,这对美国的空间观察哨来说是个不祥之兆,因为航天飞机能神不知鬼不觉地把卫星从低空轨道发射到深空。 美国的陆军空间监测和跟踪系统很难探测到这种秘密发射的卫星或识别其有效载荷,这一点使美国大伤脑筋。 如果苏联航天飞机的轨道     

ADS-B在美国

美国是“广播式自动相关监视”(ADS-B)技术研究和应用的先行者之一。继1991年,瑞典首次成功利用飞行座舱显示器(CDTI)演示ADS-B功能之后,美国从1992年就开始在芝加哥的O’Hare机场开展ADS-B技术的早期应用研究。进入21世纪,美国首先在阿拉斯加地区通用航空飞机上推广应用ADS-B技术。2002年,美国联邦航空局FAA终于出台了ADS-B数据链发展政策以及支持ADS-B技术发展的规划蓝图。一、美国的AD S-B技术发展规划(一)近期规划:(2002年—2006年)(1)定义ADS-B最初发展阶段的国内技术系统底层结构;(2)允许“袖珍型”(不具备上行广播…     

Summary of medical investigations in the U.S.S.R. manned space missions.

The results of biomedical investigations carried out in the U.S.S.R. manned space missions are discussed. Their basic result is well-documented evidence that man can perform space flights of long duration. The investigations have demonstrated no direct correlation between inflight or postflight physiological reactions of crewmembers and flight duration. In all likelihood, this can be attributed to the fact that special exercises done inflight efficiently prevented adverse effects of weightlessness. However, human reactions to weightlessness need further study. They include negative calcium balance and anemia as well as vestibulo-autonomic disorders shown by crewmembers at early stages of weightlessness. Attention should be given to psychological, social-psychological and ethical problems that may also limit further increase in flight duration.     

U.S. biological experiments in space.

Past U.S. space biological experiments in space, using non-human specimens, are discussed and evaluated. Current plans for future experimentation in this field are also given.     

Aquatic modules for bioregenerative life support systems based on the C.E.B.A.S. biotechnology

Most concepts for bioregenerative life support systems are based on edible higher land plants which create some problems with growth and seed generation under space conditions. Animal protein production is mostly neglected because of the tremendous waste management problems with tetrapods under reduced weightlessness. Therefore, the “Closed Equilibrated Biological Aquatic System” (C.E.B.A.S.) was developed which represents an artificial aquatic ecosystem containing aquatic organisms which are adpated at all to “near weightlessness conditions” (fishes Xiphophorus helleri, water snails Biomphalaria glabrata, ammonia oxidizing bacteria and the rootless non-gravitropic edible water plant Ceratophyllum demersum). Basically the C.E.B.A.S. consists of 4 subsystems: a ZOOLOGICASL COMPONENT (animal aquarium), a BOTANICAL COMPONENT (aquatic plant bioreactor), a MICROBIAL COMPONENT (bacteria filter) and an ELECTRONICAL COMPONENT (data acquisition and control unit). Superficially, the function principle appears simple: the plants convert light energy into chemical energy via photosynthesis thus producing biomass and oxygen. The animals and microorganisms use the oxygen for respiration and produce the carbon dioxide which is essential for plant photosynthesis. The ammonia ions excreted by the animals are converted by the bacteria to nitrite and then to nitrate ions which serve as a nitrogen source for the plants. Other essential ions derive from biological degradation of animal waste products and dead organic matter. The C.E.B.A.S. exists in 2 basic versions: the original C.E.B.A.S. with a volume of 150 liters and a self-sustaining standing time of more than 13 month and the so-called C.E.B.A.S. MINI MODULE with a volume of about 8.5 liters. In the latter there is no closed food loop by reasons of available space so that animal food has to be provided via an automated feeder. This device was flown already successfully on the STS-89 and STS-90 spaceshuttle missions and the working hypothesis was verified that aquatic organisms are nearly not affected at all by space conditions, i . e. that the plants exhibited biomass production rates identical to the ground controls and that as well the reproductive, and the immune system as the the embryonic and ontogenic development of the animals remained undisturbed. Currently the C.E.B.A.S. MINI MODLULE is prepared for a third spaceshuttle fligt (STS-107) in spring 2001. Based on the results of the space experiments a series of prototypes of aquatic food production modules for the implementation into BLSS were developed. This paper describes the scientific disposition of the STS-107 experiments and of open and closed aquaculture systems based on another aquatic plant species, the Lemnacean Wolffia arrhiza which is cultured as a vegetable in Southeastern Asia. This plant can be grown in suspension culture and several special bioreactors were developed for this purpose. W. arrhiza reproduces mainly vegetatively by buds but also sexually from time to time and is therefore especially suitable for genetic engineering, too. Therefore it was used, in addition, to optimize the C.E.B.A.S. MINI MODULE to allow experiments with a duration of 4 month in the International Space Station the basic principle of which will be explained. In the context of aquaculture systems for BLSS the continuous replacement of removed fish biomass is an essential demand. Although fish reproduction seems not to be affected in the short-term space experiments with the C.E.B.A.S. MIMI MODULE a functional and reliable hatchery for the production of siblings under reduced weightlessness is connected with some serious problems. Therefore an automated “reproduction module” for the herbivorous fish Tilapia rendalli was developed as a laboratory prototype. It is concluded that aquatic modules of different degrees of complexity can optimize the productivity of BLSS based on higher land plants and that they offer an unique opportunity for the production of animal protein in lunar or planetary bases.     

DR.Q.SCIENCE QUEST

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U.S. prebreathe protocol

This paper identifies and describes the prebreathe protocol currently used by the U.S. Space Shuttle Program to provide astronauts the capability to safely perform extravehicular activity. A comparison of planned vs actual prebreathe experience through the STS-37 Mission is also provided.     

A 6 D.O.F. opto-inertial tracker for virtual reality experiments in microgravity.

Gravity plays a role in many different levels of human motor behavior. It dictates the laws of motion of our body and limbs, as well as of the objects in the external world with which we wish to interact. The dynamic interaction of our body with the world is molded within gravity's constraints. The role played by gravity in the perception of visual stimuli and the elaboration of human movement is an active research theme in the field of Neurophysiology. Conditions of microgravity, coupled with techniques from the world of virtual reality, provide a unique opportunity to address these questions concerning the function of the human sensorimotor system. The ability to measure movements of the head and to update in real time the visual scene presented to the subject based on these measurements is a key element in producing a realistic virtual environment. A variety of head-tracking hardware exists on the market today, but none seem particularly well suited to the constraints of working with a space station environment. Nor can any of the existing commercial systems meet the more stringent requirements for physiological experimentation (high accuracy, high resolution, low jitter, low lag) in a wireless configuration. To this end, we have developed and tested a hybrid opto-inertial 6 degree-of-freedom tracker based on existing inertial technology. To confirm that the inertial components and algorithms will function properly, this system was tested in the microgravity conditions of parabolic flight. Here we present the design goals of this tracker, the system configuration and the results of 0g and 1g testing.     

美国高超声速技术飞行器

介绍了美国正在开展的猎鹰计划及该计划的目标、组成和各组成部分的任务目标。重点介绍了该计划下研制的高超声速技术飞行器(HTV)。此外,还对HTV所涉及的关键技术进行了总结。