Lightweight Robot Arm for Capturing Large Space Debris

Effective measures to mitigate space debris are urgently required.Active removal of space debris presents the most effective measures.This study examines a micro robotic satellite with a simple robot arm for active space debris removal.In this study,the details of a proposed active space debris removal system with a robot arm are proposed.The robot arm has flexible joints and a control method to capture the target.The results of feasibility studies,the performance assumed at each step,the prototyping of the capturing robot arm with flexible joints and with a new end-effecter,and their experiment result are presented.

Capture and detumbling control for active debris removal by a dual-arm space robot

Active debris removal(ADR) technology is an effective approach to remediate the proliferation of space debris, which seriously threatens the operational safety of orbital spacecraft. This study aims to design a controller for a dual-arm space robot to capture tumbling debris, including capture control and detumbling control. Typical space debris is considered as a non-cooperative target, which has no specific capture points and unknown dynamic parameters. Compliant clamping control and the adaptive backstepping-based prescribed trajectory tracking control(PTTC)method are proposed in this paper. First, the differential geometry theory is utilized to establish the constraint equations, the dynamic model of the chaser-target system is obtained by applying the Hamilton variational principle, and the compliance clamping controller is further designed to capture the non-cooperative target without contact force feedback. Next, in the post-capture phase,an adaptive backstepping-based PTTC is proposed to detumble the combined spacecraft in the presence of model uncertainties. Finally, numerical simulations are carried out to validate the feasibility of the proposed capture and detumbling control method. Simulation results indicate that the target detumbling achieved by the PTTC method can reduce propellant consumption by up to24.11%.

Survey on research and development of on-orbit active debris removal methods

Space debris is growing dramatically with the rapid pace of human exploration of space,which seriously threatens the safety of artificial spacecraft in orbit.Therefore,the active debris removal(ADR)is important.This review aims to review the ADR methods and to advance related research in the future.The current research and development status are clearly demonstrated by mapping knowledge domain and charts.In this paper,the latest research results are classified and summarized in detail from two aspects of space debris capture and removal.The scheme comparison and evaluation of all ADR methods are performed,and the applicable scopes of various methods are summarized.Each ADR method is scored using a cobweb evaluation model based on six indicators.Future development of ADR is discussed to promote further research interest.

Prediction and experimental verification of tether net entanglement for space debris capture

This study involved simulations and experiments aimed at assessing the efficacy of a tether net in encapsulating space debris.The tether net was modeled as a spring–mass–damper system considering the influence of aerodynamic and gravitational forces and the occurrence of debris collisions.To examine the influence of collision position and size disparity between the debris and the net on debris capture status,the entanglement nodes of the net were identified.Experiments were conducted to evaluate the wrapping capabilities of the tether net,focusing specifically on debris capture.Subsequently,the results were compared with those of the numerical simulation.In the experiments,radio frequency identification was used to identify the entanglement points of the tether net.Previous studies have indicated that the ideal collision point for capturing debris using a tether net with the debris intended to be captured is located at the center of the net.However,the experimental results of this study revealed that a collision position that is slightly shifted from the center of the tether net is more advantageous for capturing debris in terms of tether net entanglement.

Optimal planning for a multi-debris active removal mission with a partial debris capture strategy

In this paper,a new mission model,called a multi-debris active removal mission with partial debris capture strategy,is proposed.The model assumes that a platform only captures part of the scheduled debris at a time and then releases these debris pieces to a disposal orbit.This process is then repeated until all of the scheduled debris is removed.A genetic algorithm with a multiparameter concatenated coding method is designed to optimize the plan of a multi-debris active removal mission with a partial debris capture strategy.A set of six pieces of debris and a set of 10 pieces of debris are selected to demonstrate the proposed planning method.The result confirms the effectiveness of the genetic algorithm with the multi-parameter concatenated coding method.The new mission model provides a more comprehensive decision-making framework than the existing mission models and makes it possible to further decrease mission costs.

空间碎片主动移除法律规制的构建

随着空间碎片数量的激增,当前的碎片减缓措施已难以应对外空轨道安全挑战,急需构建空间碎片主动移除机制。现行国际法在空间碎片的识别标准、主动移除决策机制和保障机制方面缺乏规定。空间碎片主动移除是所有航天国家道义上的义务。为此,国际社会应迅速行动,在联合国框架下设立国际碎片管理机构,制定相关准则,以明晰空间碎片的法律属性、移除条件与标准,并设立保障基金与责任制度,确保主动移除机制稳健发展。

Design and guidance of a multi-active debris removal mission

Space debris have become exceedingly dangerous over the years as the number of objects in orbit continues to increase.Active debris removal(ADR)missions have gained significant interest as effective means of mitigating the risk of collision between objects in space.This study focuses on developing a multi-ADR mission that utilizes controlled reentry and deorbiting.The mission comprises two spacecraft:a Servicer that brings debris to a low altitude and a Shepherd that rendezvous with the debris to later perform a controlled reentry.A preliminary mission design tool(PMDT)was developed to obtain time and fuel optimal trajectories for the proposed mission while considering the effect of J2,drag,eclipses,and duty cycle.The PMDT can perform such trajectory optimizations for multi-debris missions with computational time under a minute.Three guidance schemes are also studied,taking the PMDT solution as a reference to validate the design methodology and provide guidance solutions to this complex mission profile.

空间碎片天基主动清除技术发展现状及趋势

随着国内外航天发射任务逐年增多,大量在轨滞留的失效航天器将成为未来空间资源有效利用所面临的一个严峻挑战。空间碎片天基主动清除技术是从根源上对空间资源化利用与安全处置的措施,将提升和加强近地空间的可持续循环利用。本文明晰了空间碎片天基主动清除的概念,分析了空间碎片天基主动清除技术的发展历程,提出了其发展过程中面临的非合作目标相对导航、协调控制和捕获方式及装置等主要问题,为我国空间碎片天基主动清除技术的发展提出了有益参考。

对一种利用人造粉尘清除空间碎片新方法的理论分析

近地轨道的空间碎片污染日益严重,目前碎片数量已达到历史最高值并可能引发一系列连锁反应.进行主动碎片清除十分必要.利用粉尘主动清除近地轨道空间碎片是一种主动碎片清除的新方法.本文基于此方法的基本原理进行分析研究,建立了单颗碎片与人造粉尘作用的基本假设和机理模型,并对其作用进行定量计算分析;结合碎片的空间密度分布,对该方法的作用效果进行了定量估算,得出一些基本分析结论,有助于对新方法的客观认识.

激光驱动接力移除空间碎片的小卫星星座及可行性研究

在众多空间碎片移除技术中,天基激光烧蚀驱动是一种高效的、有广阔应用前景的移除技术,特别是针对移除海量的、尺寸在1～10 cm的危险碎片而言,更是具有独特优势。然而,这一技术对高能激光器单脉冲能量、光束质量、发射镜口径等要求很高,目前的硬件水平还达不到实用指标要求,制约了其天基应用。为了克服这些硬件技术障碍,本文另辟蹊径,利用小卫星概念,提出了由不同轨道高度小卫星平台组成小卫星星座,通过在每个小卫星平台上的激光驱动接力来逐步降低碎片轨道高度,最终达到移除空间碎片的小卫星接力移除星座的构想。基于现有的激光器性能参数,根据激光烧蚀驱动碎片动力学模型计算了单个卫星平台的移除能力,结果显示,10 J单脉冲能量激光器和0.5 m直径发射镜,能够对20 km范围内、尺寸小于10 cm碎片进行有效驱动。进而,针对空间碎片密集度高而应用最广的800 km轨道高度区域,设计了由分布在不同轨道高度的30颗小卫星组成接力驱动移除星座系统方案,通过仿真模拟计算验证了星座系统的移除碎片的可行性。该研究利用目前热门的小卫星星座,降低了天基激光移除空间碎片技术对硬件的性能要求,为该技术的应用提供了新的思路和途径,所提出的小卫星接力驱动星座系统方案也有工程参考价值。

空间碎片管辖权及主动清除的法律依据

国际法上空间物体、空间碎片的概念不明确,关于空间碎片管辖权的确定尚存争议,国际社会关于空间碎片主动清除的法律依据尚不能达成共识。根据外空系列条约的规定,可以进行"主动清除本国空间碎片"的合法性论证,例如登记国的管辖权、所有权国的所有权、发射国的监管权等。同时,根据国际法上的原则、规定和判例,可以找到有利于"主动清除非本国空间碎片"的依据,例如"同意""危机情况""船舶残骸清除"等。中国应当在做好充分法律研究的基础上,进行空间碎片主动清除技术、国际谈判策略、国内法律政策等方面的研究和建设。

单次任务中主动清除多块碎片的仿真分析

针对国内外空间活动产生的碎片,文章采用多脉冲推力作用下的轨道机动仿真方法,在主要考虑总速度增量为2 km/s的约束条件下,计算碎片清除所需要的速度增量、任务时间以及清除个数。仿真结果表明,单次任务可以清除12块分布比较集中的碎片。研究结果可为我国今后空间碎片清扫任务的设计提供参考依据。

激光空间碎片移除技术发展与展望

随着人类空间探索活动的增多,太空中由于人类活动造成的空间碎片数量急剧增长,这些空间碎片对在轨航天器的安全威胁日益增大。为了保护空间环境,保证航天器的在轨安全和轨道资源的可持续利用,最有效且一劳永逸的方法是主动清除(Active Debris Removal,ADR)。本文介绍了空间碎片主动移除技术,分析了天基和地基激光空间碎片移除技术的特点、差异及互补性,阐述了空间碎片激光移除关键问题,并给出了未来天基激光移除碎片的发展建议。

欧洲空间碎片主动清除技术进展与挑战

欧洲在空间碎片主动清除技术研究领域开展了大量工作。本文结合前期的凋研，对欧洲在这方面的技术进展进行梳理。其中，由英国萨里大学抓总的RemoveDebris演示验证试验通过前期攻关，已突破捕网、鱼叉等关键技术，将于2017年底发射升空，经国际空间站中转后，执行飞行演示验证。巳Deorbit任务在目标选择等关键技术上也开展了深入研究，正稳步推进。

论新时代背景下空间碎片减缓与主动清除的中国方案

当前空间碎片成为全球治理备受关注和亟待解决的问题。空间碎片减缓措施作为传统的治理方式,其现行的行为准则和技术标准在各国实际操作中存在减缓标准执行不到位的问题。空间碎片主动清除作为一种新兴技术治理方式,亟待国际社会通过谈判制定新规则来规制主动清除行为。当前空间碎片治理的紧迫性,需要大国发挥倡导和引领作用来完善其治理结构。新时代中国在全球治理体系中的作用日益凸显,面对空间碎片治理问题,中国应当发挥航天大国的国际担当,充分利用联合国平台,倡导构建空间碎片减缓措施的国际监管框架,并为当前快速发展的主动清除活动制定相应程序规则的治理机制;在国家层面,中国在完成空间碎片监测与应用中心实体建设的基础上,拓展各国对空间碎片监测数据的国际合作以实现数据共享的治理模式;在商业层面,中国在航天商业化浪潮中为国内企业在空间碎片减缓方面提供政策、法律、资金支持,积极促进商业实体参与国际空间可持续性评级,开展良性竞争的治理行动。

绳系系统在空间碎片清除中的应用

本文针对空间绳系系统对空间碎片清除问题进行综述分析。在介绍空间碎片及其移除任务现状的基础上,着重介绍了空间绳系系统主动移除技术,主要包括空间绳系机器人、空间绳网以及绳矛系统。在此基础上,对绳系系统主动移除中涉及的关键技术——目标捕获与目标离轨,进行了详细的研究综述与讨论。最后,阐述了空间绳系系统主动碎片移除技术存在的困难及应用前景。

空间碎片减缓“5年规则”的来龙去脉

1995年美国提出的空间碎片减缓“25年规则”在全球范围内被广泛采纳,但小卫星、大星座的迅速兴起对该规则的实际效果带来很大挑战。2022年9月,独立于白宫、向国会汇报的联邦通信委员会率先发布空间碎片减缓“5年规则”。联邦通信委员会此举维护了其在美国国内空间碎片减缓领域的领先地位。下一步,美国政府行政分支很可能会在新版《美国政府轨道碎片减缓标准做法》中采纳“5年规则”,并利用“5年规则”来引领和塑造空间碎片减缓国际规则。“5年规则”的推出预示着空间碎片减缓规则体系整体上趋于严格,可能将带动主动碎片移除技术、政策、产业的发展。

空间碎片移除能力发展,中国航天当前要务之一——空间环境治理刍议

各航天大国竞相部署大规模小卫星星座,将导致近地轨道空间碎片危机加速到来。低轨空间碎片的"雾霾式大爆发"前景,将迫使各航天大国大力发展空间碎片移除能力,同时加强在空间碎片治理方面的国际合作,但合作并不容易。空间碎片移除能力将牵引和推动航天能力发展,成为未来航天事业的一个制高点。中国在空间碎片治理方面有重要的利益,权利和责任,应制定政策和计划,培养力量,加大研发力度,加速发展空间碎片移除能力。

空间碎片环境现状与主动移除技术

概述了空间碎片环境现状和对航天活动的影响,讨论了空间碎片主动移除对保持空间碎片环境稳定的必要性。空间碎片研究重心先从防护转向减缓,再转到主动移除,最终是清洁空间。评述了空间碎片主动移除技术现状,指出天基激光主动移除空间碎片技术具有很好的工程应用潜力。

一种低轨废弃目标的捕获与回收方案

如何清除轨道上日益增多的废弃目标已成为国内外航天活动无法回避的现实问题和迫切需解决的问题。针对低轨道大型废弃目标回收问题,基于天基回收技术的概念,提出了一种新型组合式柔性捕获回收方案。使用空间绳网捕获废弃目标后通过充气式增阻离轨方式进行被动离轨,再利用充气式进入减速技术(inflatable entry decelerator technology,IRDT)进行再入、减速并返回地面。根据方案建立了动力学模型,开展了仿真计算分析。仿真结果表明,该方案技术可行,可用于未来空间目标的捕获和回收。