美国主力运载火箭的性能和管理

运载火箭技术是航天事业的基础技术之一。研究美国运载火箭技术的发展有助于中国相关领域的技术进步和规划。分析美国现役主力运载火箭的性能特点、项目整合、发射任务和未来规划可以看出：美国采取整合航天企业的形式促进国内火箭技术的发展；中型和重型运载火箭市场定位层次分明；运载火箭技术的发展注重降低成本；发射新型太空栽具的任务将使运载火箭在未来的太空事业中扮演更为重要的角色。     

月球借力发射火星探测器方法研究

为了使运载火箭能够适应更多的火星探测器发射窗口要求,本文提出了一种借用月球引力发射火星探测器的新方案：在满足运载火箭要求的条件下将探测器送入经过月球附近的过渡轨道,利用月球引力改变探测器的运动速度,使得探测器进入地火转移轨道.文中给出了一种两阶段搜索的数值方法,设计了月球借力的火星探测器入轨参数,得到满足运载火箭入轨要求的月球借力地火转移轨道.与传统的地火转移轨道相比,探测器入轨速度差别不大,但是本文提出的转移轨道改善了对入轨点近地点俯角的约束条件,降低了对火箭上面级滑行时间的要求.文中通过一个算例表明了该方法的可行性,仿真结果表明,该方法提高了火箭对发射窗口的适应性,同时也为今后的火星及其他行星际探测器发射任务提供了一种新的选择.     

俄设计出新型液体燃料火箭发动机

俄罗斯“能源机器”科学生产联合公司最近设计出新型液体燃料火箭发动机“RD - 12 0” ,新型发动机将能使“天顶- 3SL”液体燃料运载火箭的推力从目前的 85吨提高到 93吨。据俄塔社报道 ,“RD - 12 0”发动机是俄罗斯与乌克兰合作完善“天顶 - 3SL”液体燃料运载火箭计划的内容之一。今后 ,乌克兰“南方机器”科学生产联合公司将利用新设计出的“RD - 12 0”发动机 ,对“天顶 - 3SL”运载火箭的第二级推进器进行改造 ,提高火箭的推进能力 ,同时减少大量火箭元件的重量 ,以提高火箭的运载能力。“天顶 - 3SL”液体燃料运载火箭长 61米 …     

俄研制6座多次往返式载人飞船

为了满足未来空间站的建设需要,俄罗斯正在研制有6个座位的多次往返式太空载人飞船。据报道,新式飞船将在俄现有的“联盟”型载人飞船的基础上开发而成,其形状如同没有手柄的熨斗。飞船将由2名太空飞行员控制飞行,可乘坐4名宇航员或乘客,此外还可搭载70 0公斤的货物。按设计,飞船的发射重量为14 5吨,与“联盟”飞船一样,新式飞船在发射时位于运载火箭的顶部。俄“能源”火箭航天集团负责飞船开发项目的科学计算中心副主任索特尼科夫介绍说,已被命名为“快速帆船”的新式飞船从2 0 0 0年开始研制,如果开发资金充足将在2 0 10年前开发出来,他…     

意大利公布再入飞行器试验计划

意大利航天局（CIRA）公布了投资1．2亿美元的实验性无人太空载具（USV—X）再入飞行器计划。USV—X将于2010年搭载欧空局的“织女”号运载火箭或印度火箭发射进入亚轨道。     

国内外运载火箭POGO抑制技术研究进展

本文描述了美国、前苏联、欧洲、日本和中国等国内外运载火箭跷振（POGO）抑制技术研究的发展历程及进展,并总结出国内外火箭POGO抑制技术的特点,以及在小POGO和气蚀动力学等方面带来的启示.美国的POGO抑制技术研究经历了大力神2——土星V——航天飞机——具体问题具体分析等4个阶段的发展历程,中国的POGO抑制技术研究也类似经历了331工程——载人航天工程——新一代火箭——40 Hz问题等4个阶段.由此可知,POGO振动抑制呈现出＂事前理论预示难度大、事后危害后果严重、解决过程漫长曲折＂的特点,必须在重大航天工程实施前开展研究.     

韩国向航天国家行列迈进

韩国第一个航天中心日前在全罗南道高兴郡外罗老岛开工建设 ,按计划到 2 0 0 5年具备发射卫星的能力。这标志着韩国正在迈向自主研发卫星和运载火箭并具有独立发射能力的航天国家行列。外罗老岛航天中心占地 5 0 0万平方米 ,计划投资额为1 5 0 0亿韩元 (约合 1 2 7亿美元 )。整个航天中心包括火箭发射架、发射总控室、火箭总装厂、火箭推进器试验室、气压中心和供参观的太空体验馆等 1 1项设施 ,全部工程计划在2 0 0 5年完工。韩国总统卢武铉说 ,韩国正在实施“第二次科学技术立国”战略 ,而航天技术是韩国必须掌握的战略技术 ,韩国应当推…     

欧洲将全力增强航天业的国际竞争力

为增强欧洲航天业的国际竞争力 ,欧洲航天局 15国航天部长不久前一致通过了旨在继续支持阿丽亚娜 5型大推力火箭研制发射的决议 ,并就欧洲伽利略全球卫星导航定位系统计划的具体实施达成一致。欧洲航天局 15国主管航天事务的部长在航天局位于巴黎的总部举行了为期一天的部长理事会。此次会议主要讨论如何建立起欧洲独立的航天体系 ,增强与美国等国在航天领域的竞争力。欧洲航天局局长罗多塔在会后举行的新闻发布会上说 ,为增强阿丽亚娜 5型火箭在火箭发射市场上的竞争力 ,欧洲航天局成员国决定简化这种火箭工业生产中的组织环节 ,由欧洲航空…     

科技政策、科研管理评论与报道

俄航天预算明年将超过 2 50亿卢布俄罗斯联邦航天署联邦项目实施与财务执行处处长舒托夫介绍说 ,根据联邦航天署制定的航天预算草案 ,俄 2 0 0 5年航天预算资金将超过 2 5 0亿卢布 (1美元约合 2 9卢布 ) ,比今年增长 2 0亿卢布。据悉 ,明年俄航天预算资金中约有 182 .7亿卢布将被用于实施联邦航天项目 ,占全部航天预算资金的 72 .6 % ,用于发展“格洛纳斯”卫星定位系统目标项目的资金为 11.7亿卢布 ,用于租赁拜科努尔发射场等军事技术合作的费用为 34.5亿卢布 ,用于建设专门设施的费用为 10 .7亿卢布 ,其他费用为 11.9亿卢布。根据俄联邦航…     

中国载人运载火箭POGO抑制技术研究

系统研究中国载人运载火箭飞行中出现的POGO现象.为解决首次载人飞行中出现的POGO问题,提出变能量蓄压器的POGO抑制方案,成功抑制了＂8 Hz＂POGO异常振动,改善了航天员的乘坐环境.     

运载火箭全箭动特性三维建模技术

目前国内运载火箭动力学特性建模以梁模型为主,但梁模型是对运载火箭三维结构的一种简化,存在若干弊端.采用三维建模方法可以克服这些弊端.总结了作者近几年开展的运载火箭三维建模的研究工作,提出了运载火箭三维建模方法,包括硬壳与半硬壳结构建模方法、夹芯结构建模方法、发动机架及发动机建模方法、燃料液体建模方法、非结构质量建模方法以及连接建模方法.尤其针对液体建模,提出了燃料液体杆单元建模方法,使液体建模工作大为简化.通过工程实例应用以及和试验的对比,证明了建模方法的适用性.同时也提出了运载火箭建模当中的不确定因素.     

嫦娥三号月球车机械臂探测点定位方法

结合中国嫦娥三号月球车探测的科学应用目标,提出了一种基于投影变换的机械臂探测点定位方法.该方法在总结鱼眼镜头成像模型基础上,建立球面投影与透视投影间的转换关系,求得球面投影中像主点坐标和球半径,利用相关参数将球面投影图像转化为透视投影图像;结合月球车上鱼眼相机的安装位置相对固定,将转换后的透视投影图像重采样生成核线影像.利用相关系数和最小二乘匹配,在鱼眼相机核线影像上实现特征点的亚像素级匹配.通过前方交会计算探测点的三维坐标,并结合探测点邻域点坐标拟合最佳空间平面,获取平面的法向量,即机械臂探测点的定位.采用该方法对仿真图像进行了定位计算,并将计算值与仿真真值进行比较,总误差约为2 mm.实验结果表明,该方法完全能够满足嫦娥三号月球车机械臂探测的定位精度.     

Studies in Babylonian lunar theory: part III. The introduction of the uniform zodiac

This paper is the third of a multi-part examination of the Babylonian mathematical lunar theories known as Systems A and B. Part I (Britton, AHES 61:83–145, 2007) addressed the development of the empirical elements needed to separate the effects of lunar and solar anomaly on the intervals between syzygies, accomplished in the construction of the System A lunar theory early in the fourth century B.C. Part II (Britton, AHES 63:357–431, 2009) examines the accomplishment of this separation by the construction of a successful theory depicting the variations due to lunar anomaly in System A and its subsequent adaptation in System B. The present paper examines the introduction of the uniform zodiac, necessary for any theory depicting variations depending on the position of syzygy. It addresses three questions: (1) In light of all available evidence, what is the magnitude of the constant term in the expression Δλ* = C ? 1.3828°Y, describing the difference between the Babylonian sidereal longitudes and modern tropical longitudes? (2) What considerations governed the placement of the Babylonian sidereal zodiac relative to the fixed stars? (3) When was the uniform zodiac introduced? To the first question it finds C = 3.20° ± 0.1°, scarcely different from Huber’s (Centaurus 5:192–208, 1958) estimate of 3.08°, essentially confirming Huber’s result obtained from much less data. For the second it shows that accommodating the three asterisms comprising Taurus limited the placement of the zodiac to within 3°, while the prominence of half sign multiples among the measured intervals between prominent Normal Stars led irresistibly to the choice adopted. Finally, it finds that the zodiac was introduced between ?408 and ?397 and probably within a very few years of ?400.     

The realizers and vehicles of mental representation

The neural vehicles of mental representation play an explanatory role in cognitive psychology that their realizers do not. Cognitive psychology individuates neural structures as representational vehicles in terms of the specific causal properties to which cognitive mechanisms are sensitive. Explanations that appeal to properties of vehicles can capture generalisations which are not available at the level of their neural realizers. In this paper, I argue that the individuation of realizers as vehicles restricts the sorts of explanations in which they can participate. I illustrate this with reference to Rupert’s (2011) claim that representational vehicles can play an explanatory role in psychology in virtue of their quantity or proportion. I propose that such quantity-based explanatory claims can apply only to realizers and not to vehicles, in virtue of the particular causal role that vehicles play in psychological explanations.     

嫦娥三号“玉兔号”巡视器遥操作中的关键技术

2013年12月14日,"嫦娥三号"成功地将月面着陆器和"玉兔号"巡视器送抵月球,这标志着我国已完成了探月工程中"落"月的重要阶段.嫦娥三号任务的一个关键组成部分是由地面遥操作中心控制"玉兔号"巡视器在月面非结构化环境中进行巡视和科学探测,而遥操作技术正是该组成部分成功实施的关键."玉兔号"巡视器遥操作技术主要包括巡视器的导航定位、月面地形重构、行驶路径规划和机械臂探测等关键步骤,这些步骤相互支撑与融合,保证了嫦娥三号任务的顺利实施.本文在对上述4个方面关键技术的发展和应用现状进行总结的基础上,阐述了相关的主要技术途径及其应用特点,分析了各种技术在"玉兔号"月面巡视与科学探测任务实施中的发挥的重要作用,并评述了它们的发展潜力和应用前景,对中国探月工程以及后续火星探测工程中的遥操作具有一定的指导意义.     

Swedenborg's Lunars

The celebrated Swedish natural philosopher and visionary theologian Emanuel Swedenborg (1688–1772) devoted major efforts to the establishment of a reliable method for the determination of longitude at sea. He first formulated a method, based on the astronomical observation of lunar position, while in London in 1710–12. He issued various versions of the method, both in Latin and in Swedish, throughout his career. In 1766, at the age of 78, he presented his scheme for judgment by the Board of Longitude in London. The rich archive of Swedenborg's career allows an unusually detailed historical analysis of his longitude project, an analysis rather better documented than that available for the host of contemporary projectors who launched longitude schemes, submitted their proposals to the Board of Longitude, and have too often been ignored or dismissed by historians. This analysis uses the longitude work to illuminate key aspects of Swedenborg's wider enterprises, including his scheme to set up an astronomical observatory in southern Sweden to be devoted to lunar and stellar observation, his complex attitude to astronomical and magnetic cosmology, and his attempt to fit the notion of longitude into his visionary world-view. Swedenborg's programme also helps make better sense of the metropolitan and international networks of diplomatic and natural philosophical communication in which the longitude schemes were developed and judged. It emerges that his longitude method owed much to the established principles of earlier Baroque and Jesuit natural philosophy while his mature cosmology sought a rational and enlightened model of the universe.     

The Lunar Theories of Tycho Brahe and Christian Longomontanus in the Progymnasmata and Astronomia Danica

Tycho Brahe's lunar theory, mostly the work of his assistant Christian Longomontanus, published in the Progymnasmata (1602), was the most advanced and accurate lunar theory yet developed. Its principal innovations are: the introduction of equant motion for the first inequality in order to separate the determination of direction and distance; a more accurate limit for the second inequality although requiring a more complex calculation; additional inequalities of the variation and, in place of the annual inequality in Tycho's earlier theory, a reduction in the equation of time; in the latitude theory a variation of the inclination of the orbital plane and an inequality of the motion of the nodes; a reduction in the range of variation of distance, parallax, and apparent diameter. Some of these were already present in Tycho's earlier lunar theory (1599), but all were changed in notable ways. Twenty years later Longomontanus published a modified version of the lunar theory in Astronomia Danica (1622), for the purpose of facilitating the calculation through new correction tables, and also explained his reasons for parts of the theory in the Progymnasmata. This paper is a technical study of both lunar theories.