在轨服务中空间系绳的应用及发展

针对空间系绳在空间在轨服务中的应用与发展问题，在简述空间系绳传统应用及试验情况的基础上，综述了空间绳系机器人、空间绳网机器人两类新在轨应用方式的研究和发展，主要包括动力学建模、结构设计、相对状态测量、逼近/抓捕控制、拖曳变轨等。最后进一步讨论了空间系绳未来的研究方向。     

空间系绳系统的发展及其应用前景

空间系绳系统是一项鲜为人知的航天技术，它已有几十年的发展历史。最近，俄罗斯的专家们把这项技术推向了一个新的发展阶段，现作一概括介绍。一、空间系绳系统空间系绳系统是一个人造空间物体（卫星、飞船、货物）的组合体，它们之间用一根长的挠性元件（系绳、电缆、软...     

论绳系小卫星的应用与技术可行性

借助空间系绳的作用,绳系小卫星增强与扩大了现代小卫星的能力,在空间探测与航天技术中具有独特的功能,可承担一般小卫星不能承担或难以承担的太空使命。本文阐述绳系小卫星在太空使命(空间开发与应用,空间环境探测,以及航天新技术试验与演示等)中的应用及其原理,包括建造微重力空间平台,实现机动变轨,进行空间环境探测,以及利用导体系绳装置生成电能、贮存能量、提升轨道等。通过对小型绳系系统SEDS-1、SEDS-2、PMG、TiPS飞行试验的综述与分析,论述绳系小卫星技术可行性与成熟性,包括系绳的伸展,子星的控制,系绳的切断,子星的再入,导体系绳的电动力学应用,以及长系绳生存能力等。对中国绳系小卫星的应用与技术发展提出方案设想。     

电动力系绳离轨系统关键技术简析

空间碎片引起的恶劣空间环境迫使人们研究低成本、高效率的离轨技术。文章对低地球轨道空间碎片清除技术之一——电动力系绳离轨技术的研究进行综述,首先介绍电动力系绳离轨系统的国内外研究现状,然后描述系统的动力学与控制的研究内容,预测系统离轨时间,详述系统离轨装置设计内容,最后对电动力系绳离轨系统未来的发展以及重点、难点做出展望。     

再论空间系绳在回收容器返回中的应用

在已有的研究结果的基础上，对空间系绳在回收容器回中的应用，作了进一步分析，包括从回收容器离开空间站至回收容器从系绳上脱落的系绳伸展运动，（２）从系绳脱落的回收容器的返回运动，（３）释放容器后的系绳的收回运动。对回收容器的动态释放，除了两阶段指数型伸展程序外，还提出了另外两种导致系绳后摆的方式。对静态释放与动态释放，不仅对系绳长度，而且对系绳张力作了计算与分析。为了系绳收回过程的稳定，不仅要施加张力     

美国家侦察办公室进行系绳研究

美国家侦察办公室进行系绳研究美国负责情报卫星采办的国家侦察办公室称他们正在利用一颗在轨系绳卫星进行系绳研究，以在某些方面弥补美国航天飞机今年２月进行的系绳卫星试验。这是该机构成立３５年来首次公开宣布它正在搞的一项空间计划。这颗卫星称为系绳物理与生存能...     

美国家侦察办准备再发射一颗系绳卫星

去年6月20日，美国国家侦察办公室向空间部署了一颗系绳卫星。这颗卫星称为系绳物理与生存能力卫星（TIPS），到去年11月初已在轨运行了20周而不折断，创下了系绳的生存纪录。它提供了有关系绳空间运行规律的最新数据，使该办公室的管理人员看到了系绳的生存能力，证实了他们的     

空间绳系组合体拖曳动力学分析及振动控制

空间绳系捕获系统捕获目标物后的组合体在拖曳离轨过程中常产生振动，为此，建立了切向连续推力作用下的空间拖曳绳系组合体面内动力学模型，并对模型进行了横向摆动与纵向振动耦合分析。针对组合体的纵向振动问题提出了一种以张力控制为内环、速度控制为外环的双闭环振动控制策略。进行了振动控制仿真分析，并根据动力学的相似性，建立地面模拟实验系统，仿真与实验结果表明该控制策略可迅速抑制组合体纵向振动、减小系绳冲击并可避免出现系绳松弛现象。     

空间非合作目标物柔性捕获技术进展

分类探讨了近年来出现的多种空间柔性捕获技术的原理及性能特点，给出了一些具有代表性的案例，结果表明：空间绳系捕获技术在理论及试验研究方面都相对成熟，是未来行之有效、可工程实现的柔性捕获方式之一。重点针对空间非合作目标物捕获中容易出现的翻滚问题，对比分析现有的几种常用的接触式消旋方法，分析表明能同时实现捕获+消旋的一步式消旋法更具有应用前景。以空间绳系捕获技术作为空间柔性捕获的代表，对其捕获后的空间绳系组合体动力学模型建立过程中的系绳模型进行了综述，指出了各种系绳模型的优缺点及适用条件。对系绳控制机构进行了分类综述，给出了设计系绳控制机构需重点关注的问题。最后对空间绳系捕获技术的发展方向做了展望。     

电动系绳离轨装置的设计与分析

电动系绳离轨效果显著,无需消耗推进剂,是处理LEO(低地球轨道)废弃航天器的有效手段。文章介绍了利用电动系绳进行离轨的原理,提出了电动系绳离轨装置所需的硬件及其设计要求;给出了电动系绳离轨装置的控制策略和工作过程,并利用系绳运动方程对电动系绳离轨的效能进行了分析。结果显示,利用电动系绳可以大大减小离轨的面积时间积。     

空间绳系研究综述

空间绳系根据原理主要分为两类:动量交换绳系和电动力绳系。文章详细介绍了两者的基本原理、动力学模型和控制策略,描述了空间绳系技术实验项目的研究情况以及绳系结构设计和生存能力问题,对空间绳系的研究热点以及发展趋势进行了预测,同时列举了大量关于空间绳系技术的参考文献。研究表明:动量交换绳系和电动力绳系都可以实现无推进剂推进,提供各种离轨和再入功能,具有广阔的应用前景。     

Tethers and debris mitigation

In recent years, the use of tethers has been proposed for reduction of space debris either through momentum transfer or use of electrodynamic effects. Tethers have been shown to at least theoretically allow for quick, elegant and cost-effective deorbit of defunct satellites or spent stages. On the other hand, the large risk that tethers themselves may pose to other satellites in orbit has been recognized as well. The large collision area of tethers, combined with operational hazards and meteoroid risk may result in a large orbital exposure. For example, in 1997, the ESA/Dutch 35-km tether deployment of YES from TEAMSAT was inhibited after an analysis of the collision risk for the case the tether operation would fail. The question rises how these two points of view compare to eachother. This paper intends to highlight a representative selection of the proposed tether applications while taking into account the added risks caused by the tethers themselves.Typical applications from recent literature will be briefly described, such as an Ariane 502 spent stage re-entry from GTO and the concept of deboost of defunct satellites by interaction of a conductive tether with the Earth magnetic field.Mass savings of the tethered sytems versus conventional equivalents will be evaluated.Based on a crude risk analysis, involving elements such as mission complexity, dynamic stability, meteoroid risk and orbital life time, a general outline of limiting factors can be given for the various applications. Special attention is reserved for implementation of mechanisms that help reduce this tether risk, such as the DUtether (Tether Degradable by Ultraviolet), utilization of airdrag and solar pressure, the effect of residual current in bare tethers, tether retrieval etc.It is proposed how a net tether-induced mitigation can be compared to that of conventional alternatives, i.e. deboost by rocket engine or a completely passive approach.This comparison is put in the perspective of an ever-increasing occupation of the space environment.It is concluded that tethers can in fact help mitigate the debris risk and that for each application a useful niche can be defined. It is argued that eliminating pollution directly after use of the precious resource of space is not only good custom, but also an important way to make the risk of debris controllable and independent of future trends. Although tethers may have large exposure in terms of area-time product, they deliver a quick cleaning service that may be appreciated by the future users of space.     

Safety implications of unscheduled situations in the operation of tethered satellite systems from the international space station

Space based experiments involving the use of tethers were examined with a view to identifying the implications of unscheduled events such as tether severance and interference between the tether and other hardware. It is the authors opinion that these type of events, which have important consequences for the operation of tethers in space, have received insufficient consideration in the extensive literature on the subject. In particular, the investigation of the interference event appears to be completely new. The examination focussed on tether experiments planned for the forthcoming International Space Station (ISS). Results were obtained through the use of a highspeed, non-linear, computer simulation model specifically designed for use with tethered satellite systems. Simulations showed that both severance and interference were possible during retrieval of the tether, particularly if ‘skip-rope’ motion is initiated. The motion following each of these incidents is predicted and shows that these unscheduled events are potentially very hazardous for the ISS. While the results of these simulations are not directly applicable to specific operations on the ISS, they fulfill the primary purpose of this paper which is the demonstration of this new technology.     

Satellite pitch and roll attitude maneuvers through very short tethers

Explored here is the feasibility of achieving satellite pitch and roll attitude maneuvers through tethers. The proposed tethered satellite system (TSS) comprises of four identical tethers connecting the auxiliary mass to the satellite at its four distinct off-centered and equiangularly spaced points. The open-loop tether length control laws have been developed in order to achieve arbitrary pitch and roll attitude slewing maneuvers. Numerical simulation of the nonlinear governing equations of motion for these tether length variations establishes the feasibility of executing fixed as well as chase-slewing maneuvers. Nearly passive nature of the proposed mechanism using very short tethers along with small auxiliary mass needed makes the concept particularly attractive for future space missions.     

Benefits and risks of using electrodynamic tethers to de-orbit spacecraft

By using electrodynamic drag to greatly increase the orbital decay rate, an electrodynamic space tether can remove spent or dysfunctional spacecraft from low Earth orbit (LEO) rapidly and safely. Moreover, the low mass requirements of such tether devices make them highly advantageous compared to conventional rocket-based de-orbit systems. However, a tether system is much more vulnerable to space debris impacts than a typical spacecraft and its design must be proved to be safe up to a certain confidence level before being adopted for potential applications. To assess space debris related concerns, in March 2001 a new task (Action Item 19.1) on the “Potential Benefits and Risks of Using Electrodynamic Tethers for End-of-life De-orbit of LEO Spacecraft” was defined by the Inter-Agency Space Debris Coordination Committee (IADC). Two tests were proposed to compute the fatal impact rate of meteoroids and orbital debris on space tethers in circular orbits, at different altitudes and inclinations, as a function of the tether diameter to assess the survival probability of an electrodynamic tether system during typical de-orbiting missions. IADC members from three agencies, the Italian Space Agency (ASI), the Japan Aerospace Exploration Agency (JAXA) and the US National Aeronautics and Space Administration (NASA), participated in the study and different computational approaches were specifically developed within the framework of the IADC task. This paper summarizes the content of the IADC AI 19.1 Final Report. In particular, it introduces the potential benefits and risks of using tethers in space, it describes the assumptions made in the study plan, it compares and discusses the results obtained by ASI, JAXA and NASA for the two tests proposed. Some general conclusions and recommendations are finally extrapolated from this massive and intensive piece of research.     

绳系卫星系统的运动与控制

绳系卫星系统的运动与控制分析,是绳系卫星应用的基础。本文的数学模型考虑了作用在子星、主星及系绳上的空气阻力以及在伸展与收回阶段主星与系绳之间的质量传递,给出了相应的具体的计算式。应用该数学模型,本文对现有的几种主要控制法,进行了模拟计算,作出评审意见。     

Coupling between structural deformation and attitude motion of large planar space structures suspended by multi-tethers

A planar space structure suspended by multi-tethers is one candidate for large and lightweight structures. For such flexible structures, coupling phenomena between structural deformation and attitude motion must be considered. In the present paper, the dynamic characteristics of a planar structure suspended by multi-tethers are investigated. Simulation results reveal that the coupling occurs for low tether stiffness. In addition, it is shown that the coupling can also occur if a number of the tethers become slack. Thermal deformation of the planar structure is one cause of tether slack. Thermal deformation and the induced attitude motion are also investigated. It is shown that roll and yaw motions become unstable due to thermal deformation. Finally, we modify the condition of the connection between sub-panels in order to reduce the overall thermal deformation, and it is confirmed that large deformation can be inhibited by the modification.     

Planar dynamics of variable length multi-tethered spacecraft near collinear Lagrangian points

This paper examines the planar dynamics of a wheel-and-spoke configured multi-spacecraft system, connected together by variable length tethers, near the second Sun–Earth Lagrangian point. The closed form solutions of the system under some simple tether length functions are determined and numerical results for the tether pitch librations under more complex tether length functions are obtained, along with the control effort required to maintain the desired tether librations.