Space Debris Remediation Research Articles

Stack-CNN algorithm: A new approach for the detection of space objects

We present a new trigger algorithm combining a stacking procedure and a Convolutional Neural Network that could be applied to any space object moving linearly or with a known trajectory in the field of view of a telescope. This includes the detection of high velocity fragmentation debris in orbit. A possible implementation is as trigger system for an orbiting Space Debris remediation system. The algorithm was initially developed as offline system for the Multiwavelength Imaging New Instrument for the Extreme Universe Space Observatory (Mini-EUSO), on the International Space Station. We evaluated the performance of the algorithm on simulated data and compared it with those obtained by means of a more conventional trigger algorithm. Results indicate that this method would allow to recognise signals with ∼1% Signal over Background Ratio (SBR) on poissonian random fluctuations with a negligible fake trigger rate. Such promising results lead us to not only consider this technique as an online trigger system, but also as an offline method for searching moving signals and their characteristics (speed and direction). More generally, any kind of telescope (on the ground or in space) such as those used for space debris, meteors monitoring or cosmic ray science, could benefit from this automatized technique. The content of this paper is part of the recent Italian patent proposal submitted by the authors (patent application number: 102021000009845).

Space Debris Mitigation and Remediation: Historical Best Practices and Lessons Learned for Economically Preserving and Utilizing Common Areas

Space debris is an increasing problem. Unlike terrestrial debris, there are no natural systems, other than exponentially diminishing atmospheric drag, to self-correct. This creates a self-perpetuating problem that worsens over time as debris collisions create more debris. This danger is exacerbated by the exponential rise in space assets from small satellites and mega constellations, projected to increase >30-fold this decade. Detection and mitigation strategies to monitor and reduce the level of space debris carried out by NASA, UNCOPUOUS, and others are admirable. They are likely a key component of any long-term strategy for space debris management. However, due to the physical nature of space debris propagation, they cannot address current problems alone. Space debris removal and remediation must be implemented in parallel to these systems. Currently, space debris removal is economically, legally, and technically infeasible. Fundamentally, this is a textbook example of a tragedy of the commons created by the self-serving actions of individuals in a shared space creating detrimental conditions for others sharing the same common resources. The purpose of this article is to find viable economic strategies that create a greater marginal benefit than marginal cost for space debris remediation. Then, exploring what legal changes, modifications, or provisions would be needed nationally and internationally to implement these economic strategies. Only after the necessary economic and legal steps have been taken can space actors move to technically address this problem—something beyond the scope of this article. To find possible paths forward, this article uses case studies to analyze the economic and legal strategies employed to address different terrestrial tragedies of the commons scenarios, particularly those in maritime settings, comparing the applications of these outcomes with current conditions in space. Case studies focus on examples in which government and private actors have worked to successfully address large public negative externalities profitably without major disruption to business practices. Finally, this article reviews some of the unique challenges of space law, weakly defined property rights, and intellectual property concerns, and their parallels and differences to the foundational law of the sea precedent. Nations and private actors are moving forward despite the mentioned concerns, pushing and testing the boundaries of what is acceptable whether the laws support them or not. A viable economic solution must be found to support the legal, institutional, and economic aspects of space debris detection, mitigation, and removal.

CNES technical considerations on space traffic management

The past 12 years, following the Feng-Yun 1C fragmentation in 2007, have witnessed a continuous increase of the orbital population, with more than 8000 new objects, representing 40% of the current orbital population. These additional objects are mostly debris, as there were only than 25% additional operational satellites compared to 12 years before. The coming 10 years may have their lot of surprises as well, with the emergence of new kind of assets in orbit including streams of very small non-maneuverable satellites, and constellations of medium size spacecraft devoted to internet. In parallel, new services are being developed, such as On-Orbit-Servicing, space tugs, potentially space debris remediation missions... As a consequence of such past and predictable evolution, it appears logical that numerous actors identify some need for a space traffic management, in order to achieve some sustainability of our orbital operations. CNES, and generally speaking France, have been proactive in this domain since decades. France was the first country to adopt a law dealing with the orbital operations in the constrained orbital environment, including space debris mitigation, and dedicated teams work on the topic for both spacecraft and launcher activities. France also benefits from a radar and telescope network enabling a national catalog to be maintained. CNES has developed all the tools necessary for the proper understanding of the current and future situation, enabling us to play a major role in all the international fora on the subject. CNES has also developed in line with NASA CARA the first “middle-man” service dealing with the conjunction data messages, leading to a very efficient collision avoidance service. This experience could well turn out to be fundamental in the preparation of potential actions in near future, discussing the need for, and helping define, an international coordination of the space traffic.

Defunct Satellites in Nearly Polar Orbits: Long-term Evolution of Attitude Motion

Abstract Low Earth orbits (LEO) are known as a region of high space activity and, consequently, space debris highest density. Launcher upper stages and defunct satellites are the largest space debris objects, whose collisions can result in still greater pollution, rendering further space missions in LEO impossible. Thus, space debris remediation is necessary, and the LEO region is a primary target of active debris removal (ADR) projects. However, ADR planning requires at least an approximate idea of the candidate objects’ attitude dynamics, which is one of the incentives for our study. This paper is mainly focused on modeling and simulating the attitude dynamics of defunct satellites. We consider a “boxwing” configuration satellite with an ellipsoid of inertia close to an oblate ellipsoid of revolution. The dynamical model takes into account the gravity-gradient torque, the torque due to the residual magnetic moment, and the torque due to eddy currents induced by the interaction of conductive materials with the geomagnetic field. A better understanding of the intermediate phase of the exponential deceleration and existing final regimes is achieved owing to a more accurate model of the eddy-current torque than in most prior research.We also show the importance of orbital precession, which contributes to the overall attitude motion evolution.

The Legal Framework for Space Debris Remediation as a Tool for Sustainability in Outer Space

The growth of orbital space debris is both a consequence of and a potential hindrance to space activities. The risks posed by space debris propagation in the most used orbital regions highlight the need to adequately address the challenges posed to the sustainability in outer space. The preservation of the access to and usability of outer space in the long-term requires that action is taken which has to be the result of both mitigation and remediation measures for existing and future space missions. As the enforcement of such technical measures will depend on adequate regulation, they need to be approached also from a legal perspective. The deficiencies in law for space debris remediation mechanisms originate from the fact that although technical concepts have been developed, the legal framework for space activities does not impose any legal obligations for debris removal and on-orbit servicing. Nevertheless, an overview of the relevant legal framework shows that there is a legal basis for the protection of the outer space environment which can, as has already been the case with space debris mitigation guidelines, be substantiated in more concrete terms by the formulation of voluntary, non-binding instruments and included in national legislation.

Mini-EUSO: A high resolution detector for the study of terrestrial and cosmic UV emission from the International Space Station

The Mini-EUSO instrument is a UV telescope to be placed inside the International Space Station (ISS), looking down on the Earth from a nadir-facing window in the Russian Zvezda module. Mini-EUSO will map the earth in the UV range (300–400nm) with a spatial resolution of 6.11km and a temporal resolution of 2.5μs, offering the opportunity to study a variety of atmospheric events such as transient luminous events (TLEs) and meteors, as well as searching for strange quark matter and bioluminescence. Furthermore, Mini-EUSO will be used to detect space debris to verify the possibility of using a EUSO-class telescope in combination with a high energy laser for space debris remediation. The high-resolution mapping of the UV emissions from Earth orbit allows Mini-EUSO to serve as a pathfinder for the study of Extreme Energy Cosmic Rays (EECRs) from space by the JEM-EUSO collaboration.

Space Debris Remediation, Its Regulation and the Role of Europe

Ever since the launch of the first space object, discarded bits and pieces ranging from disused payloads and spent upper stages to single bolts and tiny flakes of paint have been cluttering outer space, making valuable and widely used orbits and trajectories to and from Earth increasingly unsafe for future use. The response of the international community to this immediate threat to the sustainable use of outer space has been slow and haphazard, and remains limited to non-binding guidelines and technical recommendations for space debris mitigation. Recent events such as the 2007 Chinese ASAT test and the 2009 collision between an active American and an in-operational Russian communications satellite demonstrate that more needs to be done in order to develop a strong international regime on active debris remediation. Given the complexities of these issues and the lengthy nature of international negotiations, one should not expect a comprehensive legal regime for space debris mitigation and remediation to materialize any time soon. As it is in the own interest of its users to preserve outer space for future exploration and use, the regulation of debris mitigation by space agencies may well prove a valuable alternative as a starting point for binding remediation rules. Since new international initiatives in this respect are lacking, the present article looks at the various space actors in Europe, and at the role some of them may play in developing global rules of space debris remediation.

Space-based application of the CAN laser to LIDAR and orbital debris remediation

Development of pulsed lasers for space-based science missions entail many additional challenges compared to terrestrial experiments. For systems requiring short pulses ≪1 ns with energies >100 mJ and fast repetition rates >10 kHz there are currently few if no laser architectures capable of operating with high electrical efficiency >20% and have good system stability. The emergence of a mulit-channel fiber-based Coherent-Amplifying-Network or CAN laser potentially enables such capability for space based missions. Here in this article we present an analysis of two such missions scaling up in pulse energy from ≈100 mJ for a supercontinuum LIDAR application utilising atmospheric filamentation to the higher energy demands needed for space debris remediation requiring ≈10 J pulses. This scalability of the CAN laser provides pathways for development of the core science and technology where many new novel space applications can be made possible.

Space Debris Remediation, its Regulation and the Role of Europe

Ever since the launch of the first space object, discarded bits and pieces ranging from disused payloads and spent upper stages to single bolts and tiny flakes of paint have been cluttering outer space, making valuable and widely used orbits and trajectories to and from Earth increasingly unsafe for future use. The response of the international community to this immediate threat to the sustainable use of outer space has been slow and haphazard, and remains limited to non-binding guidelines and technical recommendations for space debris mitigation. Recent events such as the 2007 Chinese ASAT test and the 2009 collision between an active American and an in-operational Russian communications satellite demonstrate that more needs to be done in order to develop a strong international regime on active debris remediation. Given the complexities of these issues and the lengthy nature of international negotiations, one should not expect a comprehensive legal regime for space debris mitigation and remediation to materialize any time soon. As it is in the own interest of its users to preserve outer space for future exploration and use, the regulation of debris mitigation by space agencies may well prove a valuable alternative as a starting point for binding remediation rules. Since new international initiatives in this respect are lacking, the present article looks at the various space actors in Europe, and at the role some of them may play in developing global rules of space debris remediation.

On-line estimation of inertia parameters of space debris for its tether-assisted removal

This paper presents a new methodology for on-line inertia parameters estimation for a rigid space debris captured by a tethered system, based on a new dynamics model of the system where the base satellite (chaser) and the space debris (target) are modeled as rigid bodies and the attachment points of the tether are offset from the centers of mass of the two bodies. Parameters estimation of unknown debris is critical for subsequent tasks in the space debris remediation mission, in particular, for debris retrieval and de-orbiting. In the proposed algorithm, the chaser and target are modeled as rigid bodies, the latter with unknown inertia parameters. Then, the parameters identification problem is formulated and solved in three phases. First, a coarse estimate of the target mass is obtained during the post-capture phase, while the length of tether is much longer than the offsets of base and target satellite, and the rigid body model is degenerated to a mass point model. Then, with a proper tension control scheme and the coarse estimate used as an initial guess, the debris is retrieved smoothly and a precise mass estimate is achieved during the first half of the retrieval. Finally, when the tether is retrieved relatively short and the rigid body model is used, moments of inertia and the offsets of the space debris will be estimated with a proper tension control scheme for rigid body model.

Space debris and the need for space traffic control

This report summarises the presentations which took place at the ‘Space Traffic Control – Is the Space Debris Problem Solvable?’ conference hosted by the Royal Aeronautical Society on the 2nd July 2013. The conference sought to promote discussion over methods to deal with the issue of space debris in particular and speakers included representatives from the European Space Agency, the United Kingdom Space Agency, practitioners and academia. Themes which emerged during the conference included the urgency of the problem of space debris, the need for short-term and long-term solutions, the necessity for the development and implementation of space debris remediation technologies to complement existing mitigation efforts and, last but not least, the wider applications of space traffic control. Regarding the sub-title of the conference, ‘is the space debris problem solvable?’, it would appear from the presentations that while there is the potential for future management of the issue through debris remediation and harmonised mitigation efforts, no comprehensive solutions exist at the time of writing.

Space Debris Remediation: The Public International Legal Status of Jurisdiction and Control of Space Objects

This paper examines the question of international legal jurisdiction and control of space objects. The international legal status of a space object, particularly the legality of jurisdiction and control, is a prerequisite to either international or national remediation efforts. The international community must understand what the legal status of these objects is and thereafter consider what their status could and/or should be given the public policy objectives of remediation. While public international space law does speak, to some extent, to the legal status of such objects, a close examination of public international space law reveals that the legal regime is either silent, ambiguous, or speaks to a point contrary to the public policy goal of facilitating and promoting space debris remediation.

High-power-pulsed 1054-nm laser-induced shock pressure and momentum, and energy coupling to iron-nickel and stony meteorites

Shock waves generated on eight meteorite and two Al targets by 5.4–5.6 J, 20-ns pulsed Nd:glass laser at 1054 nm generated peak pressures from 0.7 to 11 Gpa. The shock-induced particle velocities in the targets versus time was measured interferometrically. The target momentum coupling and mechanical momentum/energy coupling was highest for the Al. Among the meteorites the coupling was greatest for the Fe-Ni, which maintained physical integrity, and lowest for the stony meteorites, all of which disintegrated. Using particle velocity measurements, shock results are interpreted in terms of target fragmentation, inhomogeneity, and microstructural characteristics which are the dominant target parameters effecting energy and momentum coupling. Normalized values for the shocked material velocity and peak pressure in the targets compare favorably to similar experimental work on Al targets. Applications to modeling high-velocity meteoroid impact with planetary atmospheres, space debris remediation, and near-Earth object material interactions are discussed.