转型下的美军空间力量发展

美国从1997年明确“军事转型”以来，相继制定了一系列重要的军事空间力量发展规划，如美国空军航天司令部(AFSPC)于1998年公布的《长期规划——2020年设想》(43称《2020设想》)以及分别于2001年和2003年公布的《2004财年及以后战略主导规划》和《2006财年及以后战略主导规划》(简称《2004规划》和《2006规划》)。这些规划从作战概念、作战任务领域的思路提出了美军的空间力量结构，《2006规划》还进一步明确提出美军必须实现军事能力向空间转型，要分阶段、有重点地发展“空间力量增强、空间对抗、空间力量运用和空间支持”等武器装备，确保美军空间作战能力的优势地位，以获得“全谱”优势。     

发射消息

美空间探索技术公司的“猎鹰”1火箭8月2日在太平洋中部夸贾林环礁奥麦利克岛美国陆军里根试验场进行发射时因级间分离问题失败。箭上携带了3颗小卫星，分别是太空开发公司为美国国防部作战快速反应航天办公室建造的“开路者”（重83.5公斤）以及美国航空航天局的“纳帆”D和“制药星风险评定”（PRESat）（各重4公斤），另外还利用上面级上的空间携带了太空服务有限公司的“天堂”07天葬有效载荷。     

太空资源开发技术体系研究

为解决地球可持续发展面临的战略性资源重大问题和规模化太空探索面临原位资源补给重大挑战,太空资源开发已成为当前国际航天发展的前沿热点领域。在阐明太空资源开发的概念和内涵、深入分析国内外技术发展现状与趋势的基础上,结合太阳系资源分布特点,提出了太阳系资源开发体系架构和“天工开物”倡议设想。以人类社会发展紧密相关的战略性矿产资源开发为核心,以水冰资源开发和水基推进剂制备为基础,以地球为中心,由近及远,分阶段建设月球资源开发体系、近地小天体采矿体系、火星资源开发体系、主带小行星采矿体系、类木行星探索开发体系及内行星探索开发体系,逐步构建全太阳系资源的开发能力。     

我国首颗“种子卫星”将上天

据《解放日报》报道，我国准备发射第一颗专门用于空间农作物育种的返回式“种子卫星”。目前发射所需的各种技术条件已经具备，国家农业部、中国空间技术研究院以及中科院正在积极做好各项准备工作，一旦时机成熟，即可操作实施。利用返回式卫星搭载农作物种子，开展空间育种技术研究和探索，是发展现代农业的一项全新尝试，也为培育更多农作物优质良种，实现农业高产、优质、高效开辟了诱人的前景。在此之前，我国已成功地完成了十多次农作物种子卫星搭载育种试验，并培育出了“太空水稻”、“太空小麦”、“太空青椒”、“太空番茄”等一…     

中国三管齐下应对空间碎片

作为一个负责任的航天大国，中国高度重视“太空环保”，目前已逐渐形成监测预警、航天器防护和空间环境保护三大工程体系应对空间碎片问题，有效减缓了空间碎片的产生，得到国际社会好评。空间碎片是指人类在航天活动中产生的太空废弃物，也称“太空垃圾”。     

国际空间资源开发与利用现状及趋势研究

<正>近年来,作为提升国家基础创新能力、丰富人类认知、拓展人类生存空间的重要领域,太空持续受到主要航天国家的高度关注,各国纷纷制定太空政策,加强对空间探索的战略部署,尤其是对提升深空探测技术创新和空间资源开发利用的投入。但目前来看,空间资源开发处于“窗口期”,太空军事化趋势明显,空间资源“争夺”日趋白热化。随着越来越多的国家和组织进入太空领域,我国太空力量建设、空间资源开发与利用面临严峻复杂形势。     

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”系统卫星的控翩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，能按照美国联合太空运行中心的需求与空军的地面太空监视系统（由光学望远镜、雷达组成）整合共同执行任务。     

建设空间作战实验室开展太空作战研究

“谁能控制空间，谁就能控制地球”。美军的太空作战演习首次将太空作为作战行动的主要场所，标志着美军太空战略正在发生巨大转变。演习的直接目的是检验美国空军航天司令部的作战指挥系统、航天系统的运行状况以及航天系统与地面系统的配合能力。更深层次的目的，则是 加强美军的太空战威慑能力，凭借其太空系统向美国的敌人发出微妙但却清晰的警告。本文分析了美国太空演习的种种情况，提出了建设航天作战实验室，以研究由空间军事开发而引起的太空作战理论、作战原则与战争形态嬗变性产生的巨大影响。     

载人月球科研试验站建设规划及设想

进入21世纪以来，月球再次成为太空探索的焦点，许多国家提出各自的探月计划。区别于在美国60年前完成的阿波罗工程，未来月球探测的重点聚焦月球的长期建设与开发。如何充分利用当前的技术积累，在有限的运载能力和合理的发射运营成本条件下，建设载人月球科研试验站，实现月球极端环境下的长期运行是一个值得关注和研究的课题。结合当前国内外载人航天与探月工程发展情况，提出我国载人月球科研试验站人货分落、分段建设的规划设想。通过对安全性设计、乘组规模、环控生保需求、选址等展开分析，明确初步月球科研试验站建设需求，并提出满足2人长期月面驻留“2+1”构型月球科研试验站方案。     

美国反卫星武器综述

虽然近年来禁止太空军事化的呼声与日俱增，但鉴于卫星在现代战争中的重要作用，为争夺空间优势，保证国家安全，研制发展反卫星武器必将成为军事强国竞相研究的一个具有战略意义的课题。美国虽公开表示不进行太空军事化的相关研究，但美国国家安全和空间管理组织委员会的一份报告认为，当前世界上没有任何一个国家像美国这样依赖空间系统，因此美国必须有能力“保护太空资产免受敌方攻击”。“使敌方不能利用太空来威胁美国利益”，并且在更广泛的意义上有助于“阻止和防御针对美国本土、军事基地、盟国、海外和空间利益展开的攻击”。     

Spaceflight effects on consecutive generations of peas grown onboard the Russian segment of the International Space Station

In the period from March 2003 to April 2005 we fulfilled five experimental cultivations of genetically marked dwarf pea species in greenhouse Lada installed in the Russian segment (RS) of the International Space Station (ISS). The purpose of this series of experiments was to make morphologic and genetic analysis of pea plants grown in successive generations.According to our results, pea growth and development over the full cycle of ontogenesis (from seed to seed) taking place in space greenhouse Lada were not different as compared with the ground control plants. In addition, four successive pea crops gathered in space flight did not loose their reproductive functions and formed viable seeds.Genetic analysis of the plants grown from the “space” and “ground” seeds produced by the first to fourth successive crops was performed using the methods of chromosomal aberrations count and Random Amplified Polymorphic DNA (molecular method). No genetic polymorphism was found either in the experimental or control crops. This can serve as a sound argument for the supposition that the genetic apparatus of plants is not impacted by exposure of several successive generations to the conditions of space flight.     

小天体柔性附着状态协同估计方法

针对小天体附着过程易发生倾覆、反弹导致任务失败问题,提出“柔性附着”概念,替代传统小天体探测的刚性附着模式,为提高小天体附着任务可靠性提供新的解决思路和技术途径。在此基础上,针对柔性着陆器的状态估计问题展开研究。首先建立了柔性着陆器近似模型,提出了柔性着陆器“等效面”概念及柔性着陆器姿态的近似表征方式,进而提出了柔性附着状态协同估计方法,并通过数值仿真检验了柔性着陆器状态协同估计的可行性。     

利用载人航天器进行热控涂层舱外搭载试验研究

为了解空间环境对热控涂层性能的影响,文章设计了舱外热控涂层搭载试验方案,包括试验件配置、在轨试验和回收方法。试验件在轨试验期间安放在载人航天器密封舱前舱门外,暴露于空间环境中;在实现对接、建立组合体后,航天员不需太空行走即可实施对搭载试验件的回收及再次安装等操作。该方案若成功应用并回收试验件至地面,我国将首次获得热控涂层空间飞行试验数据。     

运载火箭摇摆发动机与全箭动力学特性耦合关系研究

针对运载火箭“摆动发动机-伺服回路”负载频率低,可能影响全箭弹性模态稳定性的问题,首先建立了包含“发动机-伺服回路”动力学模型的全箭动力学模型,分析了“发动机－伺服回路”负载频率对伺服机构传递函数和控制系统开环传递函数特性的影响,指出了“发动机－伺服回路”负载频率与箭体弹性模态之间的动力学耦合关系,给出了保证弹性模态稳定的谐振频率判据,最后计算了保证全箭弹性模态稳定的负载频率边界值,并通过仿真算例验证了结果的正确性。研究结果表明,“发动机－伺服回路”局部的负载频率通过惯性负载力矩作用与全箭弹性模态形成耦合,当负载频率位于上、下边界值范围之内时就会导致某些弹性模态不稳定,因此在实际工程中应对负载频率进行限制,以保证运载火箭的飞行安全。
     

Symmetric periodic solutions of the Hill’s problem. I

The planar circular Hill’s problem is considered, as well as its limiting integrable variant called the Hénon problem, for which the original Hill’s problem is a singular perturbation. Among solutions to the Hénon problem there are a countable number of generating solutions-arcs that are uniquely determined by the condition of successive passage through the origin of coordinates—singular point of equations of motion of the Hill’s problem. Using the generating solutions-arcs as “letters” of a certain “alphabet”, one can compose, according to some rules, the “words”: generating solutions of families of periodic orbits of the Hill’s problem. The sequence of letters in a word determines the order of orbit transfer from one invariant manifold to another, while the set of all properly specified words determine the system’s symbolic dynamics.     

空间碎片国际机制发展趋势分析

文章通过对空间碎片国际机制(多边谈判机制)的分析,指出其发展趋势,从而为中国参加相关谈判工作提供参考。空间碎片国际机制的发展已呈现出明显的政策化、法律化和制度化的趋势。无论是从外空利益争夺、外空战略实现,还是从中国航天事业可持续发展、中国航天立法体系完善的角度来讲,积极参加空间碎片技术合作与规则制定的国际谈判都具有重要意义。从国内建设上来看,中国应尽快制定“技术—政策(战略)—法律”三位一体的解决思路和具体方案;从国际层面看,可以借鉴美国一直坚持和贯彻的“技术—政策—国内规则—国际软法—国际法”外空策略,来开展空间碎片减缓和清除等方面的技术与规则制定的合作。     

Space manufacturing in the construction of solar power satellites

This paper deals with ongoing research work concerning energy budget and cost of the solar Satellite Power System (SPS).The fundamental model of such a total system including ground and space facilities, transportation vehicles, power satellites and rectennas is presented. The main purpose of this model is to examine the applicability of different construction scenarios to allow comparison under nearly identical constraints.Using this model in a first attempt the blankets—meaning the main part of the space segment by weight, energy investment needs and cost—are chosen representatively for the energy and cost comparison of two construction alternatives of the same SPS concept. These construction alternatives are defined just by ground and space based manufacturing of the solar blankets, while all other subsystems, operations and the transportation profiles are considered to be kept the same.It can be shown that the energy “payback” time does not only depend on the SPS concept selected but also very much on the construction and implementation scenario. The cost comparison of these alternative approaches presents not very significant differences but advantages for the space manufacturing option with potential higher differences for a less conservative approach which may apply benefits of space manufacturing meaning, for example, considerable mass savings in space.Some preliminary results are discussed and an outlook is given over the next steps to be investigated, comprising the extension of the fundamental model to include use of lunar raw materials.     

World economics for mankind's frontier

In Acta Astronautica, Vol. 56, No. 5, March 2006, at ISSN0094-5765 there appears the article entitled “Will space actually be the Final Frontier of humankind?” written by Giancarlo Genta, and Michael Rycroft. This Acta Astronautica article requires amplification on the economic side. The writer of this article was personally present at the Apollo 11th launchings for the first landing on the Moon, by Buzz Aldrin and others. The Apollo 11 take off to the Moon, from Cape Carnival, did not leave the situation “so humankind seems forever to be bound to its own planet!” There was nothing pessimistic about the launch of Apollo 11. It is written that there was a lack of vision at that time, which is also not correct. The ‘Final Frontier’ myth was never mentioned on that occasion. At Apollo 11 we did take planet earth's “first faltering step for mankind” on the path towards a space faring civilization, exactly as these two authors later correctly mention. Now with the US Presidential initiatives “Moon, Mars and Beyond,” the authors suggested that it “will depend on social, political and economic issues rather than technological and scientific ones.” This Academy Note respectfully submits that all of these factors social, political and economic issues, plus psychological and scientific ones, instead of, “rather than technical and scientific ones” are going to be the determining factors of the speed of progress of the exploration of the entire universe, and particularly the sun in our Milky Way Galaxy. Russia and Ukraine are now on same, deep-space policy directions. The attention of the readers of this Academy Note is called to the current “Cosmic Collision” excellent presentation at the Hayden Planetarium, located at the Museum of National History in the City of New York. It shows the past, the present and the future of international humankind in exploring space and the creation of the universe, with particular reference to the protons of our sun, for our Milky Way Galaxy.     

Walter Hohmann's contributions towards space flight: an appreciation on the occasion of the centenary of his birthday

In 1923 Hermann Oberth published his book “Die Rakete zu den Planetenräumen” (The Rocket into Planetary Space), in 1924 Max Valier's book “Der Vorstoss in den Weltenraum” (The Advance into Space) appeared while in the U.S.A. already in 1919 Robert H. Goddard reported on his rocket experiments. Altogether different from the publications just mentioned was a book entitled “Die Erreichbarkeit der Himmelskörper” (The Attainability of Celestial Bodies) published in 1925. Its author was Dr.-Ing. Walter Hohmann, born 18 March 1880, civil engineer for the city authorities of Essen, who had already made, during World War I, calculations as to the amount of fuel, initial mass and flight time necessary for flights from the Earth to other planets. The transfer trajectories investigated by Hohmann and today attributed with his name have a great practical significance for space flight onto the present. In the lecture a critical appreciation of Hohmann's work is given.     

航天器反应式碎片规避动作规划方法

提出一种航天器反应式碎片规避动作规划方法，首先以扰动流体动态系统(IFDS)算法作为动作规划的基础算法，通过其中的总和扰动矩阵对航天器的轨道速度矢量进行修正，实现轨道机动规避；然后，建立基于双延迟深度确定性策略梯度(TD3)深度强化学习算法的反应式动作规划方法，通过TD3在线优化IFDS规划参数，实现对碎片群的“状态-动作”最优、快速规避决策。在此基础上，将优先级经验回放和渐进式学习策略引入该方法中，提升训练效率。最后，仿真结果表明，所提方法可使航天器安全规避多发、突发、动态且形状各异的空间碎片群，且具有较好的实时性。