微小碎片对航天器舷窗玻璃损伤状况的跟踪研究

空间微小碎片环境比较复杂,其来源包括人为产生的碎片及微流星体。空间微小碎片不仅速度较高,而且数量庞大。它们频繁撞击航天器外表面,包括舷窗部位,特别是对航天飞机舷窗已造成巨大危害,使长期服役的国际空间站舷窗玻璃存在安全隐患。文章简要介绍了空间微小碎片对航天飞机和空间站舷窗玻璃的损伤状况,以及NASA对此做出的改进措施,这些跟踪研究成果可为我国长寿命、高可靠航天器舷窗结构设计提供参考依据。     

美国载人航天商业运输的发展

研究了美国载人航天商业运输的发展现状和趋势。美国在取消星座计划之后,实施商业乘员和货物项目,将依靠商业运输器实现＂国际空间站＂的乘员和货物运输,以缩短＂后航天飞机＂时代（航天飞机退役后）运输的断档期。美国商业乘员和货物项目包括商业轨道运输服务（COTS）计划、商业再补给服务（CRS）计划和商业乘员开发（CCDev）计划...     

The private solution to the space transportation crisis

Confused and short-sighted decisions dominated by political expediency have been made about US space policy in the past 30 years. Overly large and ambitious systems have been chosen, resulting in today's crisis in space transportation. The history of commercial aircraft development offers an alternative example of producing in a range of sizes and capabilities for a wide variety of users, and shows that the space transport industry could benefit from applying the decision-making processes used in private enterprise. The authors examine strategies for privatization of space transportation and conclude that policy support for the commercial launch industry must be continued. NASA must be reoriented towards its basic research function, and more government services should be bought from the private sector.     

Problems of providing completeness of the methane-containing block-jet combustion in a rocket-ramjet engine's combustion chamber

Some problems of methane-containing hydrocarbon fuel combustion are discussed. It seems that reduction of methane burnout zone length is one from main problems of designing new type engine. It is very important at the creation of combustion chambers of a rocket-ramjet engine for prospective space shuttle launch vehicles.     

Nuclear waste disposal in space: Implications of advanced space transportation

Previous studies have shown that the disposal of nuclear waste in space is promising as a practical and economically plausible option, based on use of the first generation space shuttle. The promise brightens if we consider use of more effective second generation systems such as fully reusable single-stage-to-orbit transports. These vehicles, with simpler more reliable flight characteristics and with operational economics at least twenty times more favorable than the first shuttle, can become available in the early 1990s when the nuclear waste problem will have grown to truly serious proportions. This paper surveys both vertical and horizontal-takeoff vehicles as they could be used for the Earth-to-orbit phase of nuclear waste disposal mission. The international nature of the nuclear waste issue is emphasized, and the suggestion is made that an international equatorial launch site be established. This launch center, apart from its inherent safety features, would serve as a focus for an international solution of the truly worldwide problem of nuclear waste disposal.     

Results of studies on advanced winged space transportation systems

This paper reviews advanced space transportation studies that have been conducted at the NASA Langley Research Center over the past several years and presents the impact of technology on vehicle size and weight. The focus of this work has been on systems that could become operational in the late 1990s and beyond with the primary emphasis on winged vehicles, both single-stage-to-orbit and two-stage concepts.     

Cost Engineering – The new paradigm for space launch vehicle design

The paper describes the basic definition and application of 'Cost Engineering' which means to design a vehicle system for minimum development cost and/or for minimum operations cost. This is important now and for the future since space transportation has become primarily a commercial business in contrast to the past where it has been mainly a subject of military power and national prestige. Several examples are presented for minimum-cost space launch vehicle configurations, such as increasing vehicle size and/or the use of less efficient rocket engines in order to reduce development and operations cost. Further a cost comparison is presented on single-stage (SSTO)-vehicles vs. two-stage launchers which shows that SSTOs have lower development and operations cost although they are larger, respectively have a higher lift-off mass than two-stage vehicles with the same performance. The design of a space tourism-dedicated launch vehicle is an extreme challenge for a cost-engineered vehicle design in order to achieve cost per seat not higher than $50,000. Finally an outlook is presented on the different options for manned Earth-to-Moon transportation modes and vehicles – another most important application of 'cost engineering', taking into account the large cost of such a future venture.     

升力式火箭动力航班化航天运输系统的关键技术挑战

航班化航天运输系统是重复使用航天运输系统的高级形式,具有高可靠、低成本、智能化、规模化、产业化等特点。基于火箭动力发展航班化航天运输系统是切实可行的技术途径之一,升力式火箭动力航班化航天运输系统具备实现类似飞机航班形式的快速周转发射能力,同时对航天运输技术也提出了新的挑战。结合航班化航天运输系统的发展态势和技术方案,重点分析了升力式火箭动力航班化航天运输系统面临的技术挑战,提出了后续研究重点与发展建议。     

一种未来大型天地往返运输系统平台气动方案

针对未来低运行成本、可直接水平起降、重复使用的大型天地往返运输系统平台飞行器研制所需重点解决的全速域气动力性能需求与气动热防护匹配等难题,分析了典型航天飞机方案所存在的能量运行缺陷等主要问题及可能的改善方案。基于放宽气动热防护设计、涡轮/冲压/火箭发动机三动力组合、嵌套式旋转机翼全速域变体、在爬升阶段将飞行动能转化为高度势能以及再入阶段“跳跃式”盘旋减速飞行轨迹控制等设计思想,从能量损失速率控制和回收利用等角度出发,开展了一种新型大型天地往返运输系统平台气动布局概念设计研究。全速域气动力/热性能工程估算以及内/外流整体气动效能初步分析结果表明,该方案可有效满足整个飞行包线内的升重平衡需求,相比航天飞机方案具有显著的整体气动效能优势,值得进一步开展深入研究。     

中国运载火箭技术发展

中国航天运输系统建设起步于20世纪60年代,经过近50年的发展,取得了举世瞩目的成就,建设了布局合理、覆盖全面的空间运输系统体系,能够将不同有效载荷发射到低、中、高不同轨道。国际合作方面,在搭载发射、商业卫星发射服务和在轨交付3个方面也取得了一定成绩。对中国航天运输系统发展成就进行了总结,对航天运输系统未来发展特别是人工智能技术应用进行了展望。     

美、俄航天器与"国际空间站"交会的轨道分析

发射航天器与"国际空间站"进行交会对接是美国和俄罗斯两国常规性的航天活动,在每次这类飞行的全过程中因特网的有关网站都将北美航天防空司令部(NORAD)追踪测量得到的航天器的轨道根数予以公布。据此对2005年7月美国航天飞机与"国际空间站"的交会对接以及2006年3-4月俄罗斯的联盟TMA-8载人飞船与"国际空间站"的交会对接过程的轨道进行了分析。     

Launch vehicles and the commercial uses of outer space : The underlying economic issues

This article discusses the economics of the demand for and supply of launch vehicles. Demand is derived from both commercial and governmental uses of space, while the supply of launch vehicles is determined by governmental needs which are rarely based on economic criteria alone. Multipurpose launches such as the Space Shuttle should be viewed as a national resource instead of a profit-seeking venture. Because of the mixing of government and private uses for space vehicles, traditional economic analysis provides only a starting point for policy decisions.     

Rationale and systems architecture for a near-term human lunar return

Early human missions to the Moon have landed on six different sites on the lunar surface. These have all been in the low-latitude regions of the near side of the Moon. Early missions were designed primarily to assure crew safety rather than for scientific value. While the later missions added increasingly more challenging science, they remained restricted to near-side, low-latitude sites. Since the 1970s, we have learned considerably more about lunar planetology and resources. A return within the next five to ten years can greatly stimulate future human space exploration activities. We can learn much more about the distribution of lunar resources, especially about hydrogen, hydrated minerals, and water ice because they appear to be abundant near the lunar poles. The presence of hydrogen opens the possibility of industrial use of lunar resources to provide fuel for space transportation throughout the solar system.This paper discusses the rationale for near-term return of human crews to the Moon, and the advantages to be gained by selecting the Moon as the next target for human missions beyond low-Earth orbit. It describes a systems architecture for early missions, including transportation and habitation aspects. Specifically, we describe a primary transportation architecture that emphasizes existing Earth-to-orbit transportation systems, using expendable launch vehicles for cargo delivery and the Space Shuttle and its derivatives for human transportation. Transfer nodes should be located at the International Space Station (ISS) and at the Earth-Moon L1 (libration point).Each of the major systems is described, and the requisite technology readiness is assessed. These systems include Earth-to-orbit transportation, lunar transfer, lunar descent and landing, surface habitation and mobility, and return to Earth. With optimum reliance on currently existing space systems and a technology readiness assessment, we estimate the minimum development time required and perform order-of-magnitude cost estimates of a near-term human lunar mission.     

固体运载火箭的技术特点与研制规律分析（英文）

Solid-propellant and liquid-propellant launch vehicles have their own characteristics, both playing an important role in space transportation systems of space powers. This paper reviews and summarizes the development history of solid-propellant launch vehicles, and analyzes their technical characteristics including multiple stages, large payloads, complex separation, diverse operation modes, fast response, and mission adaptability as well as unique advantages in launch activities. This paper analyzes and proposes four development laws for solid-propellant launch vehicles, including improving comprehensive performance, infusing heritage with innovation, unitization and seriation, and optimizing power systems. Finally, this paper proposes the opportunities and challenges faced by solid-propellant launch vehicles based on market demands.     

Launch vouchers for space science research

Recent US space policy proposes the use of space transportation ‘vouchers’ for space science payloads. Vouchers could affect the pace of space science and developments in space transportation both in the USA and internationally. This article focuses on the economic costs and benefits of vouchers, and strategies for effective programme design.     

The USA and international competition in space transportation

This article discusses the crisis facing the USA in the formulation of its space transportation policy, within the context of its overall national space policy. The author examines developments in international space transportation from 1982 to 1992, and the failure of US policies to meet foreign commercial competition in space launches. Two goals have emerged from the US policy debate: to achieve assured access to space, and to reduce the costs of sending payloads to orbit. Both goals need to be faced within the context of a wider commitment by government and private industry to space investment.     

The space elevator in the context of current space exploration policy

The space elevator is an advanced space transportation system that someday could replace chemical rockets as humanity's primary means of reaching Earth's orbit. However, before this can occur, a number of enabling technologies will need to be developed, and a variety of economic and policy questions must be addressed. The goal of this paper is to examine the feasibility of the space elevator in the context of current space exploration policy. The paper reviews the space elevator's critical enabling technologies and presents their wide variety of applications. The challenges of funding the space elevator and of building support for the program are discussed. The potential for international cooperation is considered, and the role of the space elevator in the Vision for Space Exploration is examined. The paper argues that each of the space elevator's component technologies ought to be developed independently to meet separate nearer-term objectives. The space elevator should be just one of many applications considered in making decisions to pursue research and development related to each component technology. The enabling technologies, once mature, might eventually be integrated in the construction of a full-scale space elevator from the Earth's surface to geosynchronous orbit and beyond.     

航天飞机的再入飞行走廊及再入飞行轨迹

在研究航天飞机再入返回问题时,确定再入飞行走廊和再入飞行轨迹是基础的研究问题之一。对于这方面的工作,参考文献[1]作了较详细的介绍。国内的一些作者在航天飞机方案论证时开始注意考虑这类重要的问题[2、3、4]。然而,他们所讨论的基本模型没有考虑地球自转对再入运动的影响。这种近似模型,对深入一步的方案论证就显得不能满足了。本文建立了一个精确的模型,给出与方案论证有关的仿真结果。     

Redefining safety in commercial space: Understanding debates over the safety of private human spaceflight initiatives in the United States

In 2009 President Obama proposed a budget for the National Aeronautics and Space Administration (NASA) that canceled the Constellation program and included the development of commercial crew transportation systems into low Earth orbit. This significant move to shift human spaceflight into the private sector sparked political debate, but much of the discourse has focused on impacts to “safety.” Although no one disputes the importance of keeping astronauts safe, strategies for defining safety reveal contrasting visions for the space program and opposing values regarding the privatization of U.S. space exploration. In other words, the debate over commercial control has largely become encoded in arguments over safety. Specifically, proponents of using commercial options for transporting astronauts to the International Space Station (ISS) argue that commercial vehicles would be safe for astronauts, while proponents of NASA control argue that commercial vehicles would be unsafe, or at least not as safe as NASA vehicles. The cost of the spaceflight program, the technical requirements for designing a vehicle, the track record of the launch vehicle, and the experience of the launch provider are all incorporated into what defines safety in human spaceflight. This paper analyzes these contested criteria through conceptual lenses provided by fields of science and technology policy (STP) and science, technology, and society (STS). We ultimately contend that these differences in definition result not merely from ambiguous understandings of safety, but from intentional and strategic choices guided by normative positions on the commercialization of human spaceflight. The debate over safety is better considered a proxy debate for the partisan preferences embedded within the dispute over public or private spaceflight.