分布式空间系统和航天器编队飞行辨析——兼谈航天器知识编队和精确编队飞行应用实例

小卫星技术的迅速发展和应用,为空间应用开辟了许多新领域,同时出现了很多新概念和新名词。文章对分布式卫星系统、编队飞行、星座、星群以及空间敏感器网等概念及其相互之间的区别进行了系统论述,也介绍了航天器知识编队和精确编队飞行的应用实例。     

Inflatable antenna for cubesats: Motivation for development and antenna design

CubeSats and small satellites have potential to provide means to explore space and to perform science in a more affordable way. As the goals for these spacecraft become more ambitious in space exploration, moving from Low Earth Orbit (LEO) to Geostationary Earth Orbit (GEO) or further, the communication systems currently implemented will not be able to support those missions. One of the bottlenecks in small spacecraft communication systems is represented by antennas' size, due to the close relation between antenna gain and dimensions. Current antennas for CubeSats are mostly dipole or patch antennas with limited gain. Deployable (not inflatable) antennas for CubeSats are currently being investigated, but these solutions are affected by the challenge of packaging the whole deployable structure in a small spacecraft.The work that we propose represents the first attempt to develop an inflatable antenna for CubeSats. Inflatable structures and antennas can be packaged efficiently occupying a small amount of space, and they can provide, once deployed, large dish dimension and correspondent gain. Inflatable antennas have been previously tested in space (Inflatable Antenna Experiment, STS-77). However they have never been developed for small spacecraft such as CubeSats, where the packaging efficiency, the deployment, and the inflation represent a challenge.Our study explores for the first time the possibility of developing such antenna in a way compatible with CubeSat dimensions and constraints. The research provides answers on the possible dimensions for an inflatable antenna for small satellites, on the gain and resolution that can be achieved, and on the deployment and inflation mechanism compatible with CubeSat. Future work in the development of the antenna will include the test of the antenna in flight during a specific technical demonstration mission.The article is structured as follows: context and motivation for Cubesat inflatable antenna are described; then a study to design the antenna which achieves the required performance metrics, while respecting the constraints imposed by CubeSat structure, is presented.     

Attached payloads on SPACEHAB, growing from the Space Shuttle to the Space Station

Although NASA's Space Shuttle is largely dedicated in the near term to Space Station assembly, 10–16 day flight opportunities still abound for spacecraft technology demonstration payloads, and experiments for the established earth and space science communities. This paper will present the latest developments of SPACEHAB flight systems in order to accommodate the flight needs of these communities on the Space Shuttle today and the Space Station tomorrow. In particular, some examples of payloads from these disciplines will be introduced together with the accommodation and experiment objectives.     

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.     

苏/俄交会对接技术研究

苏/俄交会对接技术的研发,最初是为20世纪60年代初苏联月球使命服务的,后来主要用于空间站的运输使命。因此,最初的＂联盟＂飞船逐步演变发展为联盟号载人飞船系列与进步号货运飞船系列。联盟号和进步号飞船应用＂指针＂或＂航向＂交会雷达系统,基本采用自动轨道交会方法。对应急运作,联盟号航天员可使用手控器;对于不载人的进步号使命...     

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.     

国外中继卫星对航天器交会对接的测控通信支持

中继卫星系统的天基测控通信是近代航天技术的重大突破,它能够有效地满足航天器交会对接的测控通信需要。文章分析了美国＂跟踪与数据中继卫星系统＂（TDRSS）和欧洲＂阿特米斯＂（ARTEMIS）中继卫星对＂自动转移飞行器＂（ATV）与＂国际空间站＂（ISS）交会对接任务的测控通信支持,总结了国外中继卫星系统支持航天器交会对接...     

航天微系统技术综述

航天微系统技术包括专用集成电路(ASIC)、片上系统(SoC)、单片微波集成电路(MMIC)、混合集成电路(HIC)等微电子技术和微机电系统(MEMS)。文章介绍了这几种技术的特点、发展现状,以及在航天中的应用情况和应用前景。ASIC与SoC技术可显著提高电子系统的集成度和性能,已在航天中得到广泛应用。MMIC技术可用于航天器通信载荷和平台的射频通信部件,已在欧美航天器中大量应用,目前正朝高频段发展。HIC主要包括厚膜HIC和薄膜HIC,特别适于功率器件和微波器件的集成,目前国外已有大量产品用于航天,如"国际空间站"(ISS)。MEMS技术可用于航天器导航、热控、推进、光学遥感与通信等系统,甚至可对航天器设计方法产生重要影响,但目前还处于起步阶段。在以上技术领域,我国虽已开展了一些研究,但与国外相比还存在较大差距。文章针对航天微系统技术的产业布局、发展方式等提出了建议,可为我国的发展规划和战略决策提供参考。     

国外深空探测推进技术发展及启示

推进系统为探测器的飞行提供所需的控制力和控制力矩,一定程度上决定了探测器的规模、最远飞行距离,乃至任务的成败,是探测器的重要分系统之一。为满足不同的深空探测任务需求,国外发展了多种形式的推进技术,但总体上仍以化学推进为主,部分采用了电推进系统,并在发展高性能低温推进技术等。对国外典型探测器推进系统进行了叙述,分析了其技术特点和发展趋势,并分别针对无人探测和载人探测应用探讨了对我国开展深空探测推进技术研究的启示。     

Technological learning through international collaboration: Lessons from the field

Countries on every continent are making new or renewed commitments to domestic satellite programs. These programs have the potential to address national needs by enhancing access to information, improving infrastructure and providing inspiration to the public. How do countries without local expertise in space technology begin a new satellite program? What is the role of international collaboration in supporting the efforts of a new space fairing country? This paper explores such questions by highlighting outputs from intensive field work in Africa and Asia. Specifically, the study explores case studies of early space activity in these countries to search for lessons about the management of a young space program. The observations from field work are compared to ideas from scholarly literature on technological learning. The findings are organized using principles from systems architecture. The paper presents a model that captures many of the influences and strategic decision areas for a collaborative satellite development project. The paper also highlights the growth of capability among African countries in the area of satellite technology.     

Federal tax incentives and financing for the reusable launch vehicle

Financing a very large new space transportation system is a major venture. It requires an initial investment of many billions of dollars and will be expected to perform successfully during its lifetime of at least twenty-five years. In the past, space systems of this magnitude have been funded, owned and operated by the government. Today, as the responsibility for opening and maintaining space systems is expected to shift from government to industry leadership, the reusable launch vehicle (RLV) presents the private sector with the challenge of finding ways of financing and building a system that will prove to be a successful private venture. The government, recognizing that it is a major customer of the RLV and that new technology must be developed for the RLV to work and to adequately reduce the cost of access to space, will fund some Initial technology development as well as provide some incentives for a private operator. This paper shows that using the current tax system's corporate investment benefits, coupled with a favorable debt financing arrangement, a profitable privately owned RLV system Is within the realm of possibility.     

General background and approach to multibody dynamics for space applications

Multibody dynamics for space applications is dictated by space environment such as space-varying gravity forces, orbital and attitude perturbations, control forces if any. Several methods and formulations devoted to the modeling of flexible bodies undergoing large overall motions were developed in recent years.Most of these different formulations were aimed to face one of the main problems concerning the analysis of spacecraft dynamics namely the reduction of computer simulation time. By virtue of this, the use of symbolic manipulation, recursive formulation and parallel processing algorithms were proposed. All these approaches fall into two categories, the one based on Newton/Euler methods and the one based on Lagrangian methods; both of them have their advantages and disadvantages although in general, Newtonian approaches lend to a better understanding of the physics of problems and in particular of the magnitude of the reactions and of the corresponding structural stresses. Another important issue which must be addressed carefully in multibody space dynamics is relevant to a correct choice of kinematics variables. In fact, when dealing with flexible multibody system the resulting equations include two different types of state variables, the ones associated with large (rigid) displacements and the ones associated with elastic deformations. These two sets of variables have generally two different time scales if we think of the attitude motion of a satellite whose period of oscillation, due to the gravity gradient effects, is of the same order of magnitude as the orbital period, which is much bigger than the one associated with the structural vibration of the satellite itself. Therefore, the numerical integration of the equations of the system represents a challenging problem.This was the abstract and some of the arguments that Professor Paolo Santini intended to present for the Breakwell Lecture; unfortunately a deadly disease attacked him and shortly took him to death, leaving his work unfinished. In agreement with Astrodynamics Committee it was decided to prepare a paper based on some research activities that Paolo Santini performed during almost 50 years in the aerospace field. His researches spanned many arguments, encompassing flexible space structures, to optimization, stability analysis, thermal analysis, smart structure, etc. just to mention the ones more related to the space field (Paolo Santini was also one the pioneers of the studies of composite wing structures, aeroelasticity and unsteady aerodynamics for aeronautical applications). Following notes have been prepared by Paolo Gasbarri who was one of Paolo Santini collaborators for almost 15 years, they will attempt to offer a sketch of Professor Santini's activity by focusing on three main topics: the stability of flexible spacecrafts, the dynamics of multibody systems and the use of the smart structure technology for the space applications.     

NASA空间环境及效应(SEE)计划进展

文章介绍了NASA在1993年提出的空间环境及效应(下称SEE)计划,其目的是明确空间环境的定义,为设计、研制能适应严酷空间环境效应的航天器系统并使其正常运行提供技术支持.该计划包括认识空间环境、飞行试验和地面试验技术的优化、更新空间环境及其效应的预测模型、保存信息并将之纳入航天器的设计流程等方面.文章描述了SEE计划目前已取得的成就和未来的打算.     

宇宙真空测量的理论与技术

在行星上和在航天器上测量行星表面同一时刻、同一位置的大气密度,会得到不同的测量数据,必须经过坐标系转换把航天器上的测量数据转换成行星坐标系的数据才可和地面观测数据比较。文章系统地归纳了宇宙真空测量的理论与技术,改正了相应的坐标转换公式,对之进行了合理性讨论,推导出分子流密度和大气压强的转换公式并建立了地面校准宇航速度定向分子流压强及压强的模拟理论,形成了比较完整的宇宙真空测量理论体系。从该理论体系出发,提出了宇宙真空测量技术方案的建议。     

技术成熟度评价在航天器地面环境试验中的应用

应国防武器装备采办中对技术状态控制、风险控制的需求,技术成熟度评价理论已在各主要航天国家得到广泛应用。通过分析美国和中国技术成熟度等级标准,提出了适用于航天器地面环境试验技术特点的8级技术成熟度等级标准和应用建议,以期为航天器地面环境试验技术状态管理提供一个行之有效的工具。     

Ultralight deployable booms for solar sails and other large gossamer structures in space

Future solar sail spacecraft which do not need any rocket motors and propellants are a promising option for long-term exploration missions in the solar system. However, they will require ultralight reflective foils and deployable booms which will allow for the unfolding of huge sails. The achievement of an acceptable ratio of reflective sail area and structural mass, which results in a still small, but significant acceleration under the photon pressure of sunlight, is extremely challenging. The same challenging deployment technique is required for the unfolding of large reflector membranes or antennas (gossamer structures). The key elements are the booms which must be stowable in a very small envelope before they reach their destination in space. Such booms were developed by DLR and have been successfully tested under zero-g-conditions during a parabolic flight campaign in February 2009. It could be convincingly demonstrated that the unfolding process is both controllable and reproducible. The booms consisted of two co-bonded omega-shaped carbonfiber half shells with 0.1 mm wall thickness each and had a weight of only 62 g per meter. Two different deployment technologies were tested, one based upon an inflatable 12 μm thick polymer hose inside the boom, the other one using an electromechanical uncoiling device at the tip of each boom. In the latter case, the uncoiling devices will radially fly away from the spacecraft, such that they become “expendable deployment mechanisms” and their mass does not count any more for the spacecraft mass that needs to be accelerated or actively controlled.     

New approaches to planetary exploration: Spacecraft and information systems design

As a result of studies undertaken during 1981 and 1982, in support of NASA's Solar System Exploration Committee activities, several new approaches have been identified for development of flight hardware as well as ground systems for the execution of U.S. planetary missions through the close of the century. This paper will summarize these new approaches for achieving lower cost in planetary exploration in three different ways:

• •• Use of modified “production line” spacecraft developed by aerospace companies for scientific and commercial use in earth orbit—study results will be discussed which demonstrate that with only modest modifications to existing earth orbiting spacecraft, excellent results can be expected at planetary targets in the inner solar system ranging from Venus to the inner portions of the asteroid belt. Use of both communications satellites typical of those used in geosynchronous applications, as well as low earth orbiting scientific and meteorological satellites will be discussed. The range of changes and the rationale for these changes required to perform planetary missions will be displayed in detail.
• •• The development of a multi-mission modular type spacecraft for planetary missions—a new approach and new flexible spacecraft design proposed for development for planetary missions to comets, main-belt asteroids, and the outer planets will be identified. This Mariner Mark II spacecraft will enable reconfiguration at low cost for adaptation to a wide range of missions. Design concepts which draw heavily on early planetary missions as well as technology developments that are expected to be available in the late 80's and early 90's will be described in detail.
• •• Development of low-cost multi-mission end-to-end information system—a system design including spacecraft command and data handling system requirements, as well as an architecture for a cost effective multi-mission operations system will be described. This system is intended to be applied to both classes of spacecraft/missions described above.

     

日本JAXA航天器环境工程验证能力研究

日本宇宙航空研究开发机构（JAXA）是负责日本航空航天开发的独立行政实体,主要承担日本航天器研究、开发、发射和运行等业务。JAXA拥有日本先进的航天基础设施和环境验证手段,集中了大量高水平的力学环境、真空热环境和特殊环境的试验测试设备,能够承担航天器系统级总装、专业测试和环境试验,也具备航天器原材料、元器件等的环境试验与评价能力。JAXA具有国际一流的航天器环境工程验证能力,对日本航天事业的飞速发展发挥了重要支撑作用。根据我国航天发展战略以及对标国际一流航天先进技术的要求,文章跟踪研究了JAXA的航天器环境工程验证能力的建设、基地布局、管理模式和标准体系等方面的成功经验,提出了我国航天器环境工程的发展建议与启示。     

闪光 X 射线技术在空间科学领域中的应用

在长时间飞行的航天器的设计中,必须考虑其表面和暴露的子系统被陨石雨和沿轨道运动碎片的高速撞击。闪光 X 射线技术是研究这一问题的基本工具之一。在美国销售的闪光 X 射线设备中有近30%是用于空间科学的研究。文章介绍了闪光 X 射线系统的性能及其在空间科学研究中的应用。