首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
罗山珍 《航天员》2009,(3):22-25
屈指一数,哈勃空间望远镜漂泊太空已19年有余。在漫长而短暂的19年里,“哈勃”完成了88万多次宇宙观测,并对29万个宇宙天体拍摄了57万多张照片。这些被“哈勃”捕捉到的天体现象或宇宙奇观,不仅震撼眼球,而且震撼心灵——原来在那遥远得有些不敢想象的太空中,竟然存在着如此多数不胜数的壮丽景象。本刊特从“哈勃”拍摄的众多照片中,精选出极少数的经典作品,以飨读者!  相似文献   

2.
正Since the successful launch on September 15,the Tiangong2 space laboratory mission commenced,5 years after the successful operation of the Tiangong 1 target spacecraft.Tiangong2 is the first spacecraft that was launched into space as part of phase two of the second step of China’s manned space program.It is the first real space laboratory for the country.Compared with Tiangong 1,Tiangong 2 will conduct more  相似文献   

3.
The results of the determination of the uncontrolled attitude motion of the International Space Station during its unmanned flight in 1999 are presented. The data of onboard measurements of three components of the angular velocity are used for this determination. These data covering an interval of slightly less than one orbit were jointly processed by the least squares method, by integrating the equations of motion of the station relative to its center of mass. As a result of this processing, the initial conditions of the motion and the parameters of the mathematical model used were estimated. The actual motion of the station has been determined for 20 such intervals during April–November. Throughout these intervals, the station rotated about the axis of the minimum moment of inertia, the latter executing small oscillations relative to the local vertical. Such a mode, known as the mode of gravitational orientation of a rotating satellite or the mode of generalized gravitational orientation, was planned before the flight. The measurements were made to verify it. The quasistatic component of the microaccelerations aboard the station is estimated for this mode.  相似文献   

4.
桂北物流业发展在北部湾(广西)经济区确定以南、北、钦、防为城市经济带的情况下面临着区位边缘化的劣势,但桂北经济发展的积累和区位优势等条件也给桂北物流业发展提供了机遇,如何定位成为桂北物流业现阶段发展亟需解决的问题。  相似文献   

5.
Karatunov  M. O.  Baranov  A. A.  Golikov  A. R. 《Cosmic Research》2021,59(6):539-539
Cosmic Research - An Erratum to this paper has been published: https://doi.org/10.1134/S0010952521120030  相似文献   

6.
Abstract

Although the term “Wayfinding” has been defined by several authors, it subsumes a whole set of tasks that involve different cognitive processes, drawing on different cognitive components. Research on wayfinding has been conducted with different paradigms using a variety of wayfinding tasks. This makes it difficult to compare the results and implications of many studies. A systematic classification is needed in order to determine and investigate the cognitive processes and structural components of how humans solve wayfinding problems. Current classifications of wayfinding distinguish tasks on a rather coarse level or do not take the navigator's knowledge, a key factor in wayfinding, into account. We present an extended taxonomy of wayfinding that distinguishes tasks by external constraints as well as by the level of spatial knowledge that is available to the navigator. The taxonomy will help to decrease ambiguity of wayfinding tasks and it will facilitate understanding of the differentiated demands a navigator faces when solving wayfinding problems.  相似文献   

7.
赫鲁尼切夫国家科研生产航天中心始建于1916年4月,原是一家汽车生产厂。1922年开始转产飞机。1961年工厂更名为赫鲁尼切夫机器制造厂,并以前苏联当时的航空部长米哈伊尔·赫鲁尼切夫的名字命名。1962年工厂转产航天产品。由于其在俄罗斯航天工业中占有举足轻重的地位,1993年该厂被国家命名为“赫鲁尼切夫国家科研生产航天中心”。赫鲁尼切夫航天中心的发展史可以生动地反映出前苏联/俄罗斯战略轰炸机、洲际弹道导弹、运载火箭、空间站以及其它航天科技的历史发展情况。该中心曾先后研制和生产了M-4型高速战略轰炸机、质子号运载火箭、礼炮…  相似文献   

8.
9.
Alan Cooper   《Space Policy》2003,19(4):85-264
For the UK, space is primarily a means to an end and not an end in itself. This approach has been described as utilitarian. The British National Space Centre describes it as user oriented: the purpose of going into space should be to provide cost-effective information or services to the users, whether these are the science community, commercial operators and customers, or public sector bodies. The new draft UK Space Strategy, published on 22 January 2003, provides the underpinning rationale for this approach, which derives in part from the very individual way in which the UK organises its interests in space.  相似文献   

10.
航天活动包括探索、开发和利用三个层次。文章从4个方面论述探索在整个航天活动中的作用和地位,认为探索是开发和利用之母,是航天国际化的主要途径,是航天软实力的重要体现,是发挥我负责任大国作用的展示;最后建议中国要加强探索类航天项目和航天活动的开展。  相似文献   

11.
Kazuto Suzuki   《Space Policy》2007,23(3):144-146
As we celebrate the 50th anniversary of the start of spaceflight and of the initiation of European integration, both these symbols of modernity seem to have stalled. We have learnt that some forms of modernity bore a heavy price, such as environmental issues. The social value of ‘progress’ has changed; this affects the types of programme that publics support. Although prestige may still be important to new spacefaring nations, it is the utility of space technology in solving terrestrial problems that is most important, while economic changes, which have made government funding tighter, have opened the door to private initiatives. As we enter the 21st century, we can still be proud of our achievements in space, but we must understand that the reasons we pursue such activity has changed.  相似文献   

12.
The value of a space traffic management system must weigh the historical and legally entrenched concept of the freedom of operation in near-Earth orbit against the potential benefits of a new regulatory regime. Most spacefaring nations do not yet exert control over the selection of orbital parameters for new space systems within their own countries, much less in an international context. The need for and potential effectiveness of such intrusive space traffic management in the foreseeable future have not yet been clearly established.  相似文献   

13.
为改善在空间站长期值守的航天员的业务生活,提出建立空间站网吧,为航天员提供因特网服务的构想。为此分析研究空间站空间因特网服务系统及其关键技术,提出空间站空间因特网服务系统构建方案。结合这一系统构建方案,一是研究解决了支持复杂异构网络运行的空间因特网网络协议设计技术,空间站空间因特网直接采用TCP/IP协议,并通过系统设计,较好地克服了TCP/IP协议不能适应空间通信链路的难题,支持采用基于TCP/IP协议的商用货架(COTS)软、硬件产品,可明显降低空间站空间因特网服务系统建设与维护成本;二是研究解决了涉及空间站测控通信网运行安全和空间信息安全的空间通信链路设计技术,空间站在同一条空间通信链路同时传输空间因特网数据和空间站测控通信数据,空间通信链路采用CCSDS的AOS协议,并通过建立虚拟的物理信道,解决了空间因特网数据和空间站测控通信数据的安全隔离问题,能满足空间站测控通信网运行安全和空间信息安全的要求。  相似文献   

14.
15.
韩增尧 《中国航天》2006,(7):39-41,46
2005年8月9日,发现号航天飞机在执行完14天的太空飞行任务后,安全返回美国爱德华兹空军基地。此次飞行是哥伦比亚号航天飞机失事后的首次飞行。虽然在此前两年半的时间里美国航宇局(NASA)耗资30多亿美元,在六个方面改善了航天飞机的性能,但整个过程并不顺利,可谓一波三折,引起了全世界的广泛关注。让美国人引以自豪的航天飞机日显老态,逐渐暴露出诸多问题,这对美国今后的航天事业也将产生深远的影响。  相似文献   

16.
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。  相似文献   

17.
道德学习和道德教育是教育上的两种不同理念的体现,其存在是有一定的哲学、心理学和伦理学理论基础的.实现道德学习的方式在于把学习的自动权交还给学生、通过创设情景来唤醒学生的道德体验、进行道德对话教学、使学生学会价值辨析、让学生进行自我的道德反思.道德学习的自主性体现了人的存在价值和生命意义,道德学习的开放性防止对学生的道德教育流于形式,道德学习的实践性培养了学生的道德能力.道德学习是一个持续的、终身的过程.  相似文献   

18.
19.
20.
China's space industry has been developed quickly and consistently setting new records for mankind in space exploration in the past 60 years. Four principles are upheld during its development. Systems engineering and overall thinking have played an important role in the development of China's space industry. What's more, the concept of systems engineering which originated from the space industry, being rooted in society, is a successful example of "Chinese theory" answering "Chinese question" and "Chinese wisdom" guiding "Chinese development", which is a trump card for the country and provides a unique business governance mode with Chinese characteristics.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号