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Space exploration is a mechanism whereby, with the use of astronomy and space technology, humans are able to explore outer space and the universe at large. In this article, the authors address space debris issues with a discussion of future space law issues along with a brief elaboration of how the adaptation took place for space debris mitigation guidelines. The history of space law formulated during the United Nations’ General Assembly is justified, along with the resolutions that took place throughout recent years. The authors also elaborate on the importance of theoretical modeling and how it could be adopted into practice utilizing the established debris mitigation guidelines. Legal and political constraints are also highlighted, along with where the future focus on legal factors should be when considering space debris mitigation.

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... On the side of passive mitigation, the IADC established basic guidelines regarding responsible behavior in outer space that are widely accepted across the global space community. Similarly, the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space set up a Long-Term Sustainability Working Group introducing technical content and definitions of the IADC debris mitigation guidelines with the aim to establish more precise principles considering the UN principles and treaties on outer space [40]. Basically, the IADC described three disposal options. ...
... However, there are no binding mechanisms requiring space organization to follow these guidelines. The states tend to follow their own amended principles and rules by referencing the UN treaties and principles [40]. ...
... As pointed out by Rajapaksa and Wijerathna, "the control of all space objects and the jurisdiction of matters relating to space objects are held by the launching state, according to the convention." [40] Moreover, the debris catalog distributed by the U.S. military is not accurate. The Russian coverage is similarly incomplete. ...
Outer space is a congested strategic domain. The issue of space debris mitigation is one of the key issues of safe space traffic. However, active debris removal (ADR) systems may raise concerns about their dual-use capabilities. In this article, the authors have analyzed the ADR systems focusing on their potential as space weapons. The article concludes that ADR systems can be utilized for harmful purposes, although with limited impact. This limited potential of ADR systems to become antisatellite weapons allow for the development of such systems keeping in place basic confidence and trust building measures. The authors believe the further commercialization of space sector could enhance the space debris mitigation efforts.
... However, although the Mitigation Guidelines are incorporated into the mission planning of many space agencies, and some countries even go beyond the guidelines, the UN requirements are not binding and non-compliance cannot be reviewed or sanctioned. The Mitigation Guidelines' non-binding legal status has led to a multitude of individual sets of rules by states and private organizations (such as the ISO) and ambiguity within the space community [5]. ...
Conference Paper
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This paper approaches the issue of space debris as a collective action problem in a global commons environment. Based on Elinor Ostrom’s research into commons management, we propose a system of polycentric governance that is no less effective and more politically feasible than the reform or creation of existing institutions like intergovernmental bodies or major treaties. Using Paul Stern’s “adapted design principles” we analyze shortcomings of the current governance structure relating to space debris and derive recommendations. The aim of these is to facilitate communication among governance nodes, empower lower-level decision-making, and build trust among stakeholders.
Current calls to remove orbital debris come from nearly every corner, including governments, militaries, private corporations, and the scientific community. While debris poses a clear threat to space operations, and while this threat will continue to grow over time, too little energy has been spent considering the second-order effects of developing the ability to remove orbital debris. An unintended consequence of debris removal is that it would weaken one of the elements of deterrence that prevent self-interested states from engaging in more frequent kinetic antisatellite tests or taking hostile actions against orbital objects. This article examines the issue of orbital debris, connects the existence of debris to deterrence, and then offers some solutions to mitigate the weakening of deterrence in the event that debris removal becomes a reality.
Over recent times there has been a rise in the number of objects placed into Earth orbit. With various countries licensing a number of large constellations, the orbital population is set to increase dramatically. A significant number of technical advances have facilitated this and, in the UK and elsewhere, this has been matched by the updating of legislation and an increased policy focus on the need for increased space surveillance and tracking. The rise of large constellations coupled with an increasing number of experimental techniques such as active debris removal or on-orbit servicing procedures means that establishing fault will be crucial if litigation is to be successful. In doing this, any legal proceedings will look at both norms of behaviour, deviation from which will point towards fault and the types and standard of evidence that will be required. This paper will outline these problems in detail. It will be proposed that what is required to map out the contours of liability are both codification of the norms for satellite operations and clarity on protocols for evidence gathering in cases where fault may be contested in orbital operations. This discussion will identify that a way in which this could be achieved is by the use of “space law games”. These are simulations, similar to military war games, in which fictional scenarios could highlight some of the key legal issues that might need to be dealt with. The paper will outline some of the ways in which the law games might work and pose questions as to what data and other considerations will be needed to make such simulations meaningful.
The second part of the spatial geopolitical analysis focuses on the traditional political and military aspects. This part is, consequently, more focused on the nature of human activity and its interaction with the physical side of the domain. The first part deals with the introduction of space law as a basic framework of the operation of actors inside the outer space. The discussion is followed by an introduction of the basic concepts related to the diplomatic relations among space actors and space’s relation to warfare. Finally, the issue of space security – mainly of orbital debris and planetary defense – is tackled. This chapter presents the reader with a comprehensive analysis of the “hard power” side of outer space activities as well as the issues related to the securing of the environment.
The need for debris mitigation is illustrated in the context of historic launch activates and operational practices. This has led to the existing space debris environment, with consequent collision flux levels that are based on detailed population and evolution models. Therefore mitigation of space debris has become a major concern for us humans lately. National space agencies have proposed many space debris mitigation measures to reduce and stabilize the predicted long term growth of space object population. Through this article we take a closer look at the mathematical analysis of three main strategies adapted to reduce and stabilize the growth of space debris.
The near-Earth orbital debris population will continue to increase in the future due to ongoing space activities, on-orbit explosions, and accidental collisions among resident space objects. Commonly adopted mitigation measures, such as limiting postmission orbital lifetimes of satellites to less than 25 years, will slow down the population growth, but will be insufficient to stabilize the environment. To better limit the growth of the future debris population, the remediation option, i.e., removing existing large and massive objects from orbit, needs to be considered. This paper does not intend to address the technical or economical issues for active debris removal. Rather, the objective is to provide a sensitivity study to illustrate and quantify the effectiveness of various remediation options. An effective removal criterion based upon mass and collision probability is developed. This study includes simulations with removal rates ranging from 5 to 20 objects per year, starting in the year 2020. The outcome of each simulation is analyzed and compared with others. The summary of the study serves as a general guideline for future debris removal consideration.
The ‘Particles-in-a-box’ (PIB) model introduced by Talent (1992) removed the need for computer-intensive Monte Carlo simulation to predict the gross characteristics of an evolving debris environment. The PIB model was described using a differential equation that allows the stability of the low Earth orbit (LEO) environment to be tested by a straightforward analysis of the equation’s coefficients. As part of an ongoing research effort to investigate more efficient approaches to evolutionary modelling and to develop a suite of educational tools, a new PIB model has been developed. The model, entitled Fast Debris Evolution (FaDE), employs a first-order differential equation to describe the rate at which new objects 10 cm) are added and removed from the environment. Whilst Talent (1992) based the collision theory for the PIB approach on collisions between gas particles and adopted specific values for the parameters of the model from a number of references, the form and coefficients of the FaDE model equations can be inferred from the outputs of future projections produced by high-fidelity models, such as the DAMAGE model. The FaDE model has been implemented as a client-side, web-based service using Javascript embedded within a HTML document. Due to the simple nature of the algorithm, FaDE can deliver the results of future projections immediately in a graphical format, with complete user-control over key simulation parameters. Historical and future projections for the 10 cm low Earth orbit (LEO) debris environment under a variety of different scenarios are possible, including business as usual, no future launches, post-mission disposal and remediation. A selection of results is presented with comparisons with predictions made using the DAMAGE environment model. The results demonstrate that the FaDE model is able to capture comparable time-series of collisions and number of objects as predicted by DAMAGE in several scenarios. Further, and perhaps more importantly, its speed and flexibility allows the user to explore and understand the evolution of the space debris environment.
Modelling studies have shown that the implementation of mitigation guidelines, which aim to reduce the amount of new debris generated on-orbit, is an important requirement of future space activities but may be insufficient to stabilise the near-Earth debris environment. The role of a variety of mitigation practices in stabilising the environment has been investigated over the last decade, as has the potential of active debris removal (ADR) methods in recent work. We present a theoretical approach to the analysis of the debris environment that is based on the study of networks, composed of vertices and edges, which describe the dynamic relationships between Earth satellites in the debris system. Future projections of the 10 cm and larger satellite population in a non-mitigation scenario, conducted with the DAMAGE model, are used to illustrate key aspects of this approach. Information from the DAMAGE projections are used to reconstruct a network in which vertices represent satellites and edges encapsulate conjunctions between collision pairs. The network structure is then quantified using statistical measures, providing a numerical baseline for this future projection scenario. Finally, the impact of mitigation strategies and active debris removal, which can be mapped onto the network by altering or removing edges and vertices, can be assessed in terms of the changes from this baseline. The paper introduces the network methodology, and highlights the ways in which this approach can be used to formalise criteria for debris mitigation and removal. It then summarises changes to the adopted network that correspond to an increasing stability and changes that represent a decreasing stability of the future debris environment.
A new orbital debris evolutionary model is being developed by the NASA Orbital Debris Program Office at Johnson Space Center. LEGEND, a LEO-to-GEO Environment Debris model, is capable of reproducing the historical debris environment as well as performing future debris environment projection. The model covers the near Earth space between 200 and 40,000 km altitude and outputs debris distributions in one-dimensional (altitude), two-dimensional (altitude, latitude), and three-dimensional (altitude, latitude, longitude) formats. LEGEND is a three-year (2001–2003) project. The historical part of the model has been completed and the future projection part is being developed/tested. The model utilizes a recently updated historical satellite launch database, two efficient and accurate propagators, and a new NASA satellite breakup model. This paper summarizes the justifications for building a full-scale three-dimensional debris evolutionary model, the overall model structure, and several key components of the model. Preliminary model predictions of debris distributions in the Low Earth Orbit (LEO), Medium Earth Orbit (MEO), and Geosynchronous Earth Orbit (GEO) regions are presented.
Active debris removal (ADR) was suggested as a potential means to remediate the low Earth orbit (LEO) debris environment as early as the 1980s. The reasons ADR has not become practical are due to its technical difficulties and the high cost associated with the approach. However, as the LEO debris populations continue to increase, ADR may be the only option to preserve the near-Earth environment for future generations. An initial study was completed in 2007 to demonstrate that a simple ADR target selection criterion could be developed to reduce the future debris population growth. The present paper summarizes a comprehensive study based on more realistic simulation scenarios, including fragments generated from the 2007 Fengyun-1C event, mitigation measures, and other target selection options.The simulations were based on the NASA long-term orbital debris projection model, LEGEND. A scenario where, at the end of mission lifetimes, spacecraft and upper stages were moved to 25-year decay orbits, was adopted as the baseline environment for comparison. Different annual removal rates and different ADR target selection criteria were tested, and the resulting 200-year future environment projections were compared with the baseline scenario. Results of this parametric study indicate that (1) an effective removal strategy can be developed using a selection criterion based on the mass and collision probability of each object, and (2) the LEO environment can be stabilized in the next 200 years with an ADR removal rate of five objects per year.
Predictions have been made by several authors that random collisions between made-made objects in Earth orbit will lead to a significant source of new orbital debris, possibly within the next century. The authors have also concluded that there are a number of uncertainties in these models, and additional analysis and data are required to fully characterize the future environment. However, the nature of these uncertainties are such that while the future environment is uncertain, the fact that collisions will control the future environment is less uncertain. The data that already exist is sufficient to show that cascading collisions will control the future debris environment with no, or very minor increases in the current low Earth orbit population. Two populations control this process: Explosion fragments and expended rocket bodies and payloads. Practices are already changing to limit explosions in low Earth orbit; it is now necessary to begin limiting the number of expended rocket bodies and payloads in orbit.
We model the orbital debris environment by a set of differential equations with parameter values that capture many of the complexities of existing three-dimensional simulation models. We compute the probability that a spacecraft gets destroyed in a collision during its operational lifetime, and then define the sustainable risk level as the maximum of this probability over all future time. Focusing on the 900- to 1000-km altitude region, which is the most congested portion of low Earth orbit, we find that – despite the initial rise in the level of fragments – the sustainable risk remains below 10-3 if there is high (>98%) compliance to the existing 25-year postmission deorbiting guideline. We quantify the damage (via the number of future destroyed operational spacecraft) generated by past and future space activities. We estimate that the 2007 FengYun 1C antisatellite weapon test represents ≈1% of the legacy damage due to space objects having a characteristic size of ⩾10 cm, and causes the same damage as failing to deorbit 2.6 spacecraft after their operational life. Although the political and economic issues are daunting, these damage estimates can be used to help determine one-time legacy fees and fees on future activities (including deorbit noncompliance), which can deter future debris generation, compensate operational spacecraft that are destroyed in future collisions, and partially fund research and development into space debris mitigation technologies. Our results need to be confirmed with a high-fidelity three-dimensional model before they can provide the basis for any major decisions made by the space community.
UNCOPUOS Space Debris Mitigation Guidelines
"UNCOPUOS Space Debris Mitigation Guidelines," Space Safety Regulations and Standards, 2010: 475-479; and IADC-02-01 Revision 1, Steering Group and Working Group 4, September 2007.
  • D A Vallado
  • P Crawford
  • R Hujsak
  • T S Kelso
D. A. Vallado, P. Crawford, R. Hujsak, and T. S. Kelso, "Revisiting Spacaetrack Report" (paper presented at the AIAA/AAS Astrodynamics Specialist Conference, Keystone, CO, 21-24 August 2006), 21-24; and Technical Report on Space Debris, Text of the Report Adopted by the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space, United Nations, 1999.
Methods for Characterization
  • National Research
  • Council
National Research Council, "Methods for Characterization," Orbital Debris: A Technical Assessment (Washington, DC: The National Academies Press, 1995): 31-61.
The Non-Technical Challenges of Active Debris Removal
  • Brian Weeden
Brian Weeden, "The Non-Technical Challenges of Active Debris Removal" (paper presented at 2nd European Workshop on Active Debris Removal, Paris, France, 18-19 June 2012).