A New Analysis of Debris Mitigation and Removal Using Networks
- Paper number
IAC-08.A6.4.9
- Author
Dr. Hugh G. Lewis, University of Southampton, United Kingdom
- Coauthor
Dr. Graham Swinerd, University of Southampton, United Kingdom
- Coauthor
Ms. Rebecca Newland, University of Southampton, United Kingdom
- Coauthor
Mr. Arrun Saunders, University of Southampton, United Kingdom
- Year
2008
- Abstract
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. In fact, even if there were no further launches into space it is suspected that the space debris population would continue to increase due to persistent collision activity involving Earth satellites already on-orbit. 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 by Liou and Johnson (2007). However, given the technological, financial and political constraints on the implementation of these schemes it is important to identify effective mitigation and removal strategies, based on reliable, robust criteria and appropriate performance metrics. In previous works, the selection of these has been accomplished on a relatively ad-hoc basis, dependent upon advances in simulation capability, and potentially optimal solutions may still remain unidentified. Consequently, we present a theoretical approach to the analysis of the debris environment that is system-led and aims to address some of the existing limitations in this domain. The new approach is based on the study of networks, composed of vertices and edges (or nodes and links), which describe the dynamic relationships between Earth satellites in the debris system.
The objective is to provide a network representation of the debris environment that can be described using statistical measures and to explore the function of mitigation and removal in this context. Future projections of the 10 cm and larger satellite population in a non-mitigation scenario, conducted with the DAMAGE model, are used to reconstruct a network in which vertices represent satellites involved in collision events and edges encapsulate information about the events, such as the kinetic energy, collision probability and longevity of the collision pair. The network is then quantified using statistical measures such as transitivity (grouping), assortativity (similarity) and betweenness (centrality), 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, highlights the ways in which this approach can be used to formalise criteria for debris mitigation and removal, and 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.
- Abstract document
- Manuscript document
IAC-08.A6.4.9.pdf (🔒 authorized access only).
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