Assessing collision algorithms for the newspace era
Assessing collision algorithms for the newspace era
The ‘NewSpace’ era of the last two decades has seen increasing disruption and innovation in the space industry driven by a growing commercial element. A new investigation of spacecraft launched between 1980 and 2017 identified an increase in the number of spacecraft being deployed into similar target orbits. This has resulted in a shift from a more random spatial distribution of objects to a situation with greater spatial structure. With collisions expected to be an increasing and leading source of space debris it is important that we understand the performance of collision models and their sensitivity to the changing environment. We believe that current collision algorithms have the potential to introduce errors in the estimation of collision probabilities when modelling NewSpace scenarios. Two probabilistic algorithms, the Cube approach (Liou et al., 2003) and the Orbit Trace method (based on Öpik, 1951) were investigated for a range of scenarios.
An implementation of the Cube algorithm was verified using the original Jovian moons case and highlighted issues relating to convergence of the average collision probability for a pair of objects and to the relationship between the collision probability and the size of the cube used. Further tests compared the collision probabilities generated by the Satellite Orbital Conjunction Reports Assessing Threatening Encounters in Space (SOCRATES) against those calculated using each of the Cube and Orbit Trace algorithms in conjunction with the SGP4 propagator. Simulations of specific sub-sets of the tracked populations for well-defined time periods showed substantial discrepancies between the different collision methods.
The results suggest some inaccuracies in the currently used collision methods, introducing additional uncertainty to the rate of population growth in simulations of the evolution of the debris environment. Further work is ongoing to investigate the relationship between this variance and spacecraft altitude to ascertain whether current models are accurately representing where fragmentations might occur.
Collision probability, Debris models, New Space, Orbital debris
274-281
Diserens, Samuel Douglas
cf4d9d41-f067-4ee1-8fda-d691c46061aa
Lewis, Hugh G.
e9048cd8-c188-49cb-8e2a-45f6b316336a
Fliege, Joerg
54978787-a271-4f70-8494-3c701c893d98
September 2020
Diserens, Samuel Douglas
cf4d9d41-f067-4ee1-8fda-d691c46061aa
Lewis, Hugh G.
e9048cd8-c188-49cb-8e2a-45f6b316336a
Fliege, Joerg
54978787-a271-4f70-8494-3c701c893d98
Diserens, Samuel Douglas, Lewis, Hugh G. and Fliege, Joerg
(2020)
Assessing collision algorithms for the newspace era.
Journal of Space Safety Engineering, 7 (3), .
(doi:10.1016/j.jsse.2020.07.021).
Abstract
The ‘NewSpace’ era of the last two decades has seen increasing disruption and innovation in the space industry driven by a growing commercial element. A new investigation of spacecraft launched between 1980 and 2017 identified an increase in the number of spacecraft being deployed into similar target orbits. This has resulted in a shift from a more random spatial distribution of objects to a situation with greater spatial structure. With collisions expected to be an increasing and leading source of space debris it is important that we understand the performance of collision models and their sensitivity to the changing environment. We believe that current collision algorithms have the potential to introduce errors in the estimation of collision probabilities when modelling NewSpace scenarios. Two probabilistic algorithms, the Cube approach (Liou et al., 2003) and the Orbit Trace method (based on Öpik, 1951) were investigated for a range of scenarios.
An implementation of the Cube algorithm was verified using the original Jovian moons case and highlighted issues relating to convergence of the average collision probability for a pair of objects and to the relationship between the collision probability and the size of the cube used. Further tests compared the collision probabilities generated by the Satellite Orbital Conjunction Reports Assessing Threatening Encounters in Space (SOCRATES) against those calculated using each of the Cube and Orbit Trace algorithms in conjunction with the SGP4 propagator. Simulations of specific sub-sets of the tracked populations for well-defined time periods showed substantial discrepancies between the different collision methods.
The results suggest some inaccuracies in the currently used collision methods, introducing additional uncertainty to the rate of population growth in simulations of the evolution of the debris environment. Further work is ongoing to investigate the relationship between this variance and spacecraft altitude to ascertain whether current models are accurately representing where fragmentations might occur.
Text
Accepted manuscript
- Accepted Manuscript
More information
Accepted/In Press date: 5 July 2020
e-pub ahead of print date: 12 July 2020
Published date: September 2020
Additional Information:
Funding Information:
The authors acknowledge support from the University of Southampton EPSRC through the Centre for Doctoral Training in Next Generation Computational Modelling (Grant No. EP/L015382/1). The authors would also like to thank ESA for providing downloads of spacecraft data from the DISCOS database and Dr. T.S. Kelso of CelesTrak for providing historical values for object radii.
Publisher Copyright:
© 2020 International Association for the Advancement of Space Safety
Keywords:
Collision probability, Debris models, New Space, Orbital debris
Identifiers
Local EPrints ID: 442515
URI: http://eprints.soton.ac.uk/id/eprint/442515
ISSN: 2468-8967
PURE UUID: 4b84e2cf-0a52-413f-8af4-a73c9f128720
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Date deposited: 17 Jul 2020 16:30
Last modified: 17 Mar 2024 05:45
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Author:
Samuel Douglas Diserens
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