可组装轻质空间结构技术研究进展

概述了当前可组装轻质空间结构的构建技术方法,具体包含嵌锁组装、堆叠组装、折叠成型、充气成型和张拉整体成型五种主流技术;以太空建造、月面栖息地和近空间飞行器为典型应用,介绍了现有可组装轻质空间结构技术的航空航天应用。最后,对比分析了各空间结构技术,讨论了现有挑战和技术难点,并对其未来发展方向进行了展望,旨在为今后航空航天任务中所需的轻量化空间结构研究提供参考。     

The relevance of economic data in the decision-making process for orbital launch vehicle programs,a U.S. perspective

Over the past fifteen years, major U.S. initiatives for the development of new launch vehicles have been remarkably unsuccessful. The list is long: NLI, SLI, and X-33, not to mention several cancelled programs aimed at high speed airplanes (NASP, HSCT) which would share some similar technological problems.The economic aspects of these programs are equally as important to their success as are the technical aspects. In fact, by largely ignoring economic realities in the decisions to undertake these programs and in subsequent management decisions, space agencies (and their commercial partners) have inadvertently contributed to the eventual demise of these efforts.The transportation revolution that was envisaged by the promises of these programs has never occurred. Access to space is still very expensive; reliability of launch vehicles has remained constant over the years; and market demand has been relatively low, volatile and slow to develop. The changing international context of the industry (launching overcapacity, etc.) has also worked against the investment in new vehicles in the U.S. Today, unless there are unforeseen technical breakthroughs, orbital space access is likely to continue as it has been with high costs and market stagnation.Space exploration will require significant launching capabilities. The details of the future needs are not yet well defined. But, the question of the launch costs, the overall demand for vehicles, and the size and type of role that NASA will play in the overall launch market is likely to influence the industry. This paper will emphasize the lessons learned from the economic and management perspective from past launch programs, analyze the issues behind the demand for launches, and project the challenges that NASA will face as only one new customer in a very complex market situation. It will be important for NASA to make launch vehicle decisions based as much on economic considerations as it does on solving new technical challenges.     

The relevance of economic data in the decision-making process for orbital launch vehicle programs, a U.S. perspective

Over the past fifteen years, major U.S. initiatives for the development of new launch vehicles have been remarkably unsuccessful. The list is long: NLI, SLI, and X-33, not to mention several cancelled programs aimed at high speed airplanes (NASP, HSCT) which would share some similar technological problems.The economic aspects of these programs are equally as important to their success as are the technical aspects. In fact, by largely ignoring economic realities in the decisions to undertake these programs and in subsequent management decisions, space agencies (and their commercial partners) have inadvertently contributed to the eventual demise of these efforts.The transportation revolution that was envisaged by the promises of these programs has never occurred. Access to space is still very expensive; reliability of launch vehicles has remained constant over the years; and market demand has been relatively low, volatile and slow to develop. The changing international context of the industry (launching overcapacity, etc.) has also worked against the investment in new vehicles in the U.S. Today, unless there are unforeseen technical breakthroughs, orbital space access is likely to continue as it has been with high costs and market stagnation.Space exploration will require significant launching capabilities. The details of the future needs are not yet well defined. But, the question of the launch costs, the overall demand for vehicles, and the size and type of role that NASA will play in the overall launch market is likely to influence the industry. This paper will emphasize the lessons learned from the economic and management perspective from past launch programs, analyze the issues behind the demand for launches, and project the challenges that NASA will face as only one new customer in a very complex market situation. It will be important for NASA to make launch vehicle decisions based as much on economic considerations as it does on solving new technical challenges.     

Inflatable composite habitat structures for lunar and mars exploration

Recent advances in materials technology have improved the performance capabilities of inflatable, flexible composite structures, which have increased their potential for use in numerous space applications. Space suits, which are comprised of flexible composite components, are a good example of the successful use of inflatable composite structures in space. Space suits employ inflatables technology to provide a stand alone spacecraft for astronauts during extra-vehicular activity. A natural extension of this application of inflatables technology is in orbital or planetary habitat structures. NASA Johnson Space Center (JSC) is currently investigating flexible composite structures deployed via inflation for use as habitats, transfer vehicles and depots for continued exploration of the Moon and Mars.

Inflatable composite structures are being investigated because they offer significant benefits over conventional structures for aerospace applications. Inflatable structures are flexible and can be packaged in smaller and more complex shaped volumes, which result in the selection of smaller launch vehicles which dramatically reduce launch costs. Inflatable composite structures are typically manufactured from materials that have higher strength to weight ratios than conventional systems and are therefore lower in mass. Mass reductions are further realized because of the tailorability of inflatable composite structures, which allow the strength of the system to be concentrated where needed. Flexible composite structures also tend to be more damage tolerant due to their “forgiveness” as compared to rigid mechanical systems. In addition, inflatables have consistently proven to be lower in both development and manufacturing costs.

Several inflatable habitat development programs are discussed with their increasing maturation toward use on a flight mission. Selected development programs being discussed include several NASA Langley Research Center habitat programs that were conducted in the 1960s, the Lawrence Livermore National Laboratory inflatable space station study, the NASA JSC deployable inflatable Lunar habitat study, and the inflatable Mars TransHab study and test program currently ongoing at NASA JSC. Relevant technology developments made by ILC Dover are also presented.     

全复合材料航天器结构探讨

质轻、价优是选择航天器结构材料的主要条件,用复合材料作航天器结构材料显然比金属材料优越。文中将通过美国海军研究所空间技术中心研制的全复合材料克莱门汀(Clementine)航天器,详细介绍采用复合材料作航天器结构件的利与弊。     

Russia's resurgence: Prospects for space policy and international cooperation

Based on a joint study initiated in 2007–2008 by the Policy planning staff (CAP) of the French Foreign Ministry and the space agency CNES, which brought together experts, researchers and industry insiders, this article considers the factors behind Russia's recent resurgence and the possible revival of its space programme. It examines how far the latter will require international cooperation in order to progress further and discusses likely areas of profitable collaboration with Europe in general and France in particular, given that country's long history of space cooperation with Russia and the need in the mid-term future to share the burden of developing ambitious new space programs. While there is in principle much potential, especially in the area of space transportation, there are also numerous challenges and uncertainties. How these are resolved will affect the level and success of any cooperative efforts of both sides.     

What is wrong with space system cost models? A survey and assessment of cost estimating approaches

Despite several decades of research and refinement in cost estimating tools and practices, the final cost of US space programs continues to exceed initial cost estimates by an average of more than 45%. Thus, program cost models not only exhibit error, they are seriously biased. A structured review surveyed techniques, approaches, models and conceptual tools related to space program cost estimating, to understand cost in complex space systems. Analysis shows problems of cost estimating result from the growing complexity of space programs, failures in managing growth, and mission failures. Although there is greater expectation for the models to accurately predict program costs, the current models used for seeking funding for large space programs are inadequate due to (1) inability to predict future, (2) lack of insight, and (3) process replaces judgment in decision making.     

Space technology for humanity: A profile for the coming 50 years

Applications of space technology have provided remarkable benefits for humanity since the dawn of the Space Age and India presents an excellent example of the way space is able to benefit developing countries in areas as divergent as communications, education, disaster management, health-care, environmental monitoring, agriculture, water management and mapping. Nevertheless access to these benefits remains inequitable, with a large number of mainly developing countries and poorer sections of society not yet able to share in them. In addition, the world faces serious global challenges in the coming 50 years. The author discusses these challenges and the way they can be met using space technology, as well as ways of making space more inclusive. Key will be creating multilateral systems of systems. Some reform of laws and policies will also be needed.     

The cost benefits of the Spacelab system to scientific investigations and space applications

In the past, one of the major problems in performing scientific investigations in space has been the high cost of developing, integrating, and transporting scientific experiments into space. The limited resources of unmanned spacecraft, coupled with the requirements for completely automated operations, was another factor contributing to the high costs of scientific research in space. In previous space missions after developing, integrating and transporting costly experiments into space and obtaining successful data, the experiment facility and spacecraft have been lost forever, because they could not be returned to earth. The objective of this paper is to present how the utilization of the Spacelab System will result in cost benefits to the scientific community, and significantly reduce the cost of space operations from previous space programs.The following approach was used to quantify the cost benefits of using the Spacelab System to greatly reduce the operational costs of scientific research in space. An analysis was made of the series of activities required to combine individual scientific experiments into an integrated payload that is compatible with the Space Transportation System (STS). These activities, including Shuttle and Spacelab integration, communications and data processing, launch support requirements, and flight operations were analyzed to indicate how this new space system, when compared with previous space systems, will reduce the cost of space research. It will be shown that utilization of the Spacelab modular design, standard payload interfaces, optional Mission Dependent Equipment (MDE), and standard services, such as the Experiment Computer Operating System (ECOS), allow the user many more services than previous programs, at significantly lower costs. In addition, the missions will also be analyzed to relate their cost benefit contributions to space scientific research.The analytical tools that are being developed at MSFC in the form of computer programs that can rapidly analyze experiment to Spacelab interfaces will be discussed to show how these tools allow the Spacelab integrator to economically establish the payload compatibility of a Spacelab mission.The information used in this paper has been assimilated from the actual experience gained in integrating over 50 highly complex, scientific experiments that will fly on the Spacelab first and second missions. In addition, this paper described the work being done at the Marshall Space Flight Center (MSFC) to define the analytical integration tools and techniques required to economically and efficiently integrate a wide variety of Spacelab payloads and missions. The conclusions reached in this study are based on the actual experience gained at MSFC in its roles of Spacelab integration and mission managers for the first three Spacelab missions. The results of this paper will clearly show that the cost benefits of the Spacelab system will greatly reduce the costs and increase the opportunities for scientific investigation from space.     

The shuttle development and its growth potential

During the next two decades, we will establish the foundation for the 21st century's accomplishments in space. The Space Shuttle vehicle will become the cornerstone for that foundation by providing economical opportunities for space exploration and utilization.Reusability of the Shuttle vehicle is the key to its economy. The major developmental challenges encountered in the Shuttle program are typified by the complexities involved in designing the reusable propulsion and thermal protection subsystems. We successfully met such challenges and are nearing the launch of the first Shuttle orbital flight.Our immediate goal is to enter the Space Shuttle operational phase because only then will we fully understand the unique capabilities of the Shuttle. Concurrent with our effort to begin Shuttle operations are our initial efforts to expand Shuttle capabilities, extending them significantly beyond those of the current baseline system.Shuttle payload capacity and mission-duration capabilities are to increase considerably during the next decade. Just as present Shuttle performance specifications and development timetables were guided by the space program plans and forecasts of the 1960s, so will the development of long-range space programs be determined by our near-future achievements. We anticipate that the Space Shuttle will play a critical role in those achievements.     

The essential role of human spaceflight

The question is: should the United States and nations at large pursue a human spaceflight program (and if so, why)? I offer an unwavering positive answer to this question, and state the reasons for it while considering the broad challenges and benefits of (human) spaceflight. Space exploration is a human activity that is intrinsically forward-looking, and as such, has positive potential. Both national and international space programs can galvanize the population, inspire the youth, foster job-creation, and motivate the existing workforce. The nature of the enterprises involved—their scale, novelty, and complexity—requires a steady and continuous upward progression toward greater societal, scientific and technological development. That is, in order to overcome the challenges of human spaceflight, progress is required. More to the point, the survival of humanity depends on expanding beyond the confines of our planet. Human spaceflight, in short, presents us with an opportunity to significantly advance the nation and the global community.     

Is it time to create a World Space Agency?

The end of the Cold War has allowed the proposal for a World Space Agency, originally proposed by the USSR, to be given serious consideration. There are clearly benefits that could accrue from the emergence of such an organization. Nevertheless it would be premature to establish it now. Rather, current efforts should be directed towards fashioning structures and activities that could serve as solid building blocks for a permanent global space institution.     

未来的深空探测与空间环境模拟

文章介绍了国内外有代表性的深空探测计划的内容、特点和意义,包括:欧空局的Exo Mars火星车、美国"2020火星车"以及中国的2020火星探测计划;金星着陆探测进展情况;欧空局木星系统探测计划"木星冰月亮探索者(JUICE)"和美国的"木卫二飞越任务(Europa Clipper)";"蜻蜓号(Dragonfly)"土卫六探测项目;美国的"彗星天体生物学探索取样返回(CAESAR)"项目;月球探测计划等。还分析了未来深空探测对空间环境模拟的具体要求,空间环境模拟对推动深空探测发展的重要意义;提出了对我国未来开展空间环境模拟试验的建议。     

Challenges to US space sustainability

With space now crucial to such a wide range of activities on Earth, the USA must ensure the sustainability of its efforts, a task that involves technological feasibility and political will. Near-term challenges include US human access to space and the Shuttle transition, funding NASA sufficiently in a time of recession, and rebuilding the country's space industrial base. Longer-term challenges will be better protecting the space environment (including the electromagnetic spectrum) from overcrowding and the effects of space weather and NEOs, and defining responsibilities for distributing climate change data and recognition of property rights for the commercial development of in-space resources. As an aid to dealing with these challenges the USA must ask itself whether there is a human future in space and seek to answer the question in the course of human and robotic exploration beyond Earth.     

Composites for large space structures

A preliminary study of advanced composites and truss-type designs for application to large space structures is discussed. The benefits of advanced composite materials for large space structures and examples of large space structure design concepts and construction techniques are presented. Criteria are developed to guide the selection of structural elements, joints, and on-orbit fabrication techniques for truss-type structures and a ranking of candidate on-orbit fabrication techniques is accomplished in accordance with the criteria developed. On the basis of study results, recommended research and development goals for design, construction, and on-orbit fabrication of large space structures are established.     

The challenge of the US space station

We are on the verge of a new era of commercial and industrial expansion in space that will have a major impact on America's future and on the future of the world. It is a turning point that will set the US national agenda in space well into the 21st century, and, as such, will have an important impact on space-related activities worldwide. The USA is now gearing up to face the challenges of this new era. James Beggs, NASA Administrator, describes the US space station programme.     

Power—industry orbital complexes of the 21st century

Soviet scientist, Leonid Leskov, discusses the state of the art and future projections of the Soviet and global industrialization of space. International cooperation for peaceful use of space are required if the huge benefits of industrialization, such as solar power stations, are to be realized.     

Human missions to Mars: new psychological challenges and research issues

Human exploratory missions to Mars represent the most exciting future vision of human space flight. With respect to the distance to travel and mission duration, these missions will provide unique psychological challenges that do not compare to any other endeavor humans ever have attempted. The present paper presents outcomes of two recent projects sponsored by the European Space Agency--Humex and Reglisse--where these challenges and risks have been analyzed in some detail, and where concepts for future research have been developed. This presentation involves three steps. At first, it will be shown that our current psychological knowledge derived from orbital spaceflight and analogue environments is not sufficient to assess the specific risks of mission into outer space. Secondly, new psychological challenges of missions to Mars will be identified with respect to three different areas: (1) individual adaptation and performance, (2) crew interactions, and (3) concept and methods of psychological countermeasures. Finally, different options and issues of preparatory psychological research will be discussed.     

The role of the united nations in promoting international cooperation in peaceful uses of outer space

The Committee on the Peaceful Uses of Outer Space (COPUOS) was established in 1959 by the United Nations General Assembly in order to review and foster international cooperation in the peaceful uses of outer space and to consider legal issues arising from the exploration of outer space. Since its establishment, the Committee has addressed such issues as benefits from space activities, the definition and delimitation of outer space and the use of the geostationary orbit, implications of remote sensing, space sciences, space-based communications, navigation and meteorological systems, as well as use of nuclear power sources in outer space, space debris and spin-off benefits of space technology. At its session in 1996, a symposium on the ‘Utilization of micro- and small satellites for the expansion of low-cost space activities, taking into particular account the needs of developing countries’ was organized by COSPAR and IAF to complement discussions on this theme. It was noted at the symposium that the increasing number of small satellites, in particular the proposed introduction of multi-satellite ‘constellations’ at low orbits, would result in concentrations of satellite mass at certain regions of space around the Earth. Special provisions would be needed to minimize the probability of satellite breakups and collisions which might create more space debris and compromise the future of spaceflight.