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Active Removal of Space Debris Expanding Foam Application for Active Debris Removal

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Active Removal of Space Debris Expanding foam application for active debris removal Final Report Authors: M. Andrenucci, P. Pergola, A. Ruggiero Affiliation: University of Pisa - Aerospace Engineering Department - Italy ACT researcher(s): J. Olympio, L. Summerer Date: 21-02-2011 Contacts: University of Pisa Tel: +39-050-967211 Fax: +39-050-974094 e-mail: [email protected] Advanced Concepts Team Tel: +31(0)715656227 Fax: +31(0)715658018 e-mail: [email protected] Ariadna ID: 10-6411 Ariadna study type: Standard Contract Number: 4000101449/10/NL/CBi Available on the ACT website http://www.esa.int/act 1 TABLE OF CONTENTS Table Of Contents .................................................................................................................. 2 Abstract .................................................................................................................................... 4 1 Introduction .................................................................................................................... 6 1.1 Active Debris Removal ......................................................................................................... 7 1.2 Foam-Based Method ........................................................................................................... 10 1.3 Mission Scenario ................................................................................................................. 14 2 Space Environment Models .................................................................................... 15 2.1 Deorbiting Time Estimation ................................................................................................ 15 2.2 Atmospheric Models ........................................................................................................... 17 2.3 Space Debris Models ........................................................................................................... 20 2.4 The NASA90 Model............................................................................................................ 21 3 Space Debris population.......................................................................................... 23 3.1 Space Debris Lists ............................................................................................................... 23 3.2 Impact Probability ............................................................................................................... 28 3.3 Suitable Target Debris ......................................................................................................... 35 4 Optimum Foam Ball Radius .................................................................................... 38 4.1 Foam balls impact probability ............................................................................................. 39 4.2 Results and performance ..................................................................................................... 43 5 Foam Generalities ........................................................................................................ 56 5.1 Foam Classes and Characteristics ....................................................................................... 57 5.2 Foam Kinds ......................................................................................................................... 58 5.3 Polymerization and Curing .................................................................................................. 64 5.4 Composite Foams ................................................................................................................ 65 6 Foam Expansion Model ............................................................................................ 67 6.1 The Analytical Model .......................................................................................................... 68 6.2 Model Validation ................................................................................................................. 71 6.3 Pressure Dependence ........................................................................................................... 75 7 Foam Identification .................................................................................................... 77 8 Platform Preliminary Sizing .................................................................................... 81 8.1 Propulsion System Identification ........................................................................................ 82 8.2 Power and Mass Budget ...................................................................................................... 87 8.3 Chemical-Electrical Comparison......................................................................................... 90 9 Foam Nucleating System ......................................................................................... 92 2 9.1 Device Concepts .................................................................................................................. 92 9.2 Issues ................................................................................................................................... 93 9.3 Characteristics Identification ............................................................................................... 97 9.4 Preliminary Design .............................................................................................................. 98 10 Mission Analysis ...................................................................................................... 102 10.1 Mission Profile .................................................................................................................. 103 10.2 Results and Considerations................................................................................................ 104 11 Hazards and Risks ................................................................................................... 107 11.1 Ground Handling ............................................................................................................... 107 11.2 Launch ............................................................................................................................... 108 11.3 Foam Ejection.................................................................................................................... 108 11.4 Re-entry Behaviour ........................................................................................................... 112 11.4.1 Impact Model ............................................................................................................. 113 11.4.2 Small Debris Impact................................................................................................... 115 11.4.3 Results ........................................................................................................................ 116 12 Conclusions .............................................................................................................. 120 12.1 Development Roadmap ..................................................................................................... 120 Bibliography ....................................................................................................................... 122 Index Of Figures ................................................................................................................ 129 Index of Tables .................................................................................................................. 132 3 ABSTRACT Controlling the amount of space debris is widely recognised as an important task to maintaining a sustainable space access for the decades to come. This is mainly due to the high risk of collisions that can easily invalidate both human and robotic mission. The topic is on the agenda of the Scientific and Technical Subcommittee and coordinated between space agencies in the Inter- Agency Space Debris Coordination Committee (www.iadc-online.org). Most current efforts focus on debris mitigation methods. The Active Space Debris Removal System proposed in this study is based on an expanding foam system. The core idea of this method is to increase the area-to-mass ratio of these objects such that the atmospheric drag can cause their natural re-entry, thus “cleaning up” different regions in the near-Earth space. The drag augmentation system proposed does not require any docking system and just an uncontrolled re-entry can follow, thus it seems a short-term application free from the usual technological issues of these debris removal systems. The drag augmentation is suggested to be performed exploiting the characteristics of the expanding foams that can nucleate almost spherical envelopes around the debris with very limited efforts of the spacecraft in charge that has the role to carry and spray the foam. Furthermore, the same method can also be conceived as a preventive system to be directly embedded in future space artificial satellites. The key technological aspect is the specific foam kind that has to be able, amongst other aspects, to significantly expand its original volume and has to be as light as possible. This approach is demonstrated to be able to deorbit any kind of debris, but it has been proven to be particularly advantageous to deorbit up to 1 ton debris within 25 years from 900 km , of course the worst case. The actual scenario performance heavily depends on the specific foam considered and its characteristics.
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