ABSTRACT Title of Dissertation: TECHNICAL AND ECONOMIC FEASIBILITY OF TELEROBOTIC ON-ORBIT SATELLITE SERVICING Brook Rowland Sullivan, Doctor of Philosophy, 2005 Dissertation directed by: Professor David L. Akin Department of Aerospace Engineering Space Systems Laboratory University of Maryland The aim of this research is to devise an improved method for evaluating the techni- cal and economic feasibility of telerobotic on-orbit satellite servicing scenarios. Past, present, and future telerobotic on-orbit servicing systems and their key capabilities are examined. Previous technical and economic analyses of satellite servicing are re- viewed and evaluated. The standard method employed by previous feasibility studies is extended, developing a new servicing decision approach incorporating operational uncertainties (launch, docking, et cetera). Comprehensive databases of satellite char- acteristics and on-orbit failures are developed to provide input to the expected value evaluation of the servicing versus no-servicing decision. Past satellite failures are re- viewed and analyzed, including the economic impact of those satellite failures. Oppor- tunities for spacecraft life extension are also determined. Servicing markets of various types are identified and detailed using the results of the database analysis and the new, expected-value-based servicing feasibility method. This expected value market assessment provides a standard basis for satellite servicing decision-making for any proposed servicing architecture. Finally, the method is demonstrated by evaluating a proposed small, lightweight servicer providing retirement services for geosynchronous spacecraft. An additional benefit of the method is that it enables parametric analysis of the sensitivity of economic viability to the probability of docking success, thus establishing a threshold for that critical value. While based on a more economically conservative approach, the new method demonstrates the feasibility of the proposed server in the face of operational uncertainties. TECHNICAL AND ECONOMIC FEASIBILITY OF TELEROBOTIC ON-ORBIT SATELLITE SERVICING by Brook Rowland Sullivan Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2005 Advisory Committee: Professor David L. Akin, Chairman/Advisor Professor Mark Austin Dr. Craig R. Carignan Professor Roberto Celi Professor M. Robert Sanner Copyright by University of Maryland Space Systems Laboratory Brook Rowland Sullivan 2005 PREFACE “Looks like your vehicle is out of gas. Would you like to buy a new one?” There has got to be a better way. ii DEDICATION To Mom & Dad and Eve, This dissertation is built upon your unwavering support, unflagging encouragement, and sustaining love. And to Debbie, Sissy, and David, Gone too soon. Dearly missed. iii ACKNOWLEDGEMENTS Many people contributed to the existence of this dissertation. Firstly, I owe thanks to Dr. Dave Akin and to David Lavery for the opportunity to work at one of the most interesting places on the planet. Thanks as well to my very patient committee members. My time at the lab started with a suggestion from Joe Parrish - thanks, I think. I also received all manner of assistance and encouragement from my lab-mates (Craig, Russ, Maki, JM, Lisa, Robs, Steves, Corde, Debbie, Mikes, and Adam) and office- mates (Evie, Sarah, and Joe). Thanks also to Kiwi, Glen, Claudia, Julianne, Brian, Phil, and Gardell for inspiration along the way. Particular thanks to Jeff Smithanik and Jeff Braden for spending a few weeks asking, “What if?” Late in the research process, Dr. Owen Brown, Dr. Albert Bosse, and Dr. Gordon Roesler asked some very good questions that led in useful directions. Thanks. And a special thanks to Dr. Mary Bowden for keeping this on the administrative rails right up to the very end. The final production of this document was ably abetted by Sarah Hall, Suneel Sheikh, Stephen Roderick, and my excellent wife, Eve. iv TABLE OF CONTENTS List of Tables xii List of Figures xvii List of Abbreviations xxiii 1 Introduction 1 1.1 Motivations . 1 1.1.1 On-Orbit Failures . 2 1.1.2 Spacecraft Life Extension . 3 1.1.3 Other Servicing Opportunities . 4 1.1.4 Advancing Robotic Capabilities . 4 1.1.5 New Launch Alternatives . 6 1.2 Dissertation Overview . 7 1.3 Contributions . 8 2 Background 10 2.1 The Satellite Servicing Problem . 10 2.1.1 Servicing Failures . 13 2.1.2 Spacecraft Lifetime Extension . 15 2.1.3 Other Services . 16 2.2 A Brief History Of On-Orbit Servicing . 17 v 2.2.1 Space Shuttle Based Satellite Servicing Missions . 17 2.2.2 Satellite Self Rescues . 20 2.2.3 Space Shuttle Based Servicing Technology Demonstrations . 20 2.2.4 Other On-Orbit Servicing Technology Demonstrations . 22 2.3 Future Servicing Technology Demonstrations . 23 2.3.1 Future Servicing Technology Flight Missions . 23 2.3.2 Dexterous Robotic Servicing Research Programs . 27 2.4 Robotic Serviceability Of Satellites . 28 2.4.1 Target Satellites . 28 2.4.2 Servicers . 29 3 Previous Satellite Servicing Economic Models 35 3.1 1981 - Manger . 35 3.2 1981 - Vandenkerckhove . 41 3.3 1985 - Vandenkerckhove . 43 3.4 1989 - Yasaka . 46 3.5 1992 - The INTEC Study . 48 3.6 1994 - Newman . 50 3.7 1996 - Hibbard . 54 3.8 1998 - Davinic . 56 3.9 1999 - Leisman . 57 3.10 2001 - Lamassoure . 59 3.11 2002 - McVey . 59 3.12 2004 - Walton . 60 3.13 Other Economic Studies . 61 3.14 Cost Estimation Methods . 62 3.15 Evaluation Of Previous Studies . 64 vi 3.15.1 Operational Uncertainty . 64 3.15.2 Comprehensive Market Assessment . 65 3.15.3 Decoupling Market Assessment From Servicer Design . 65 4 A New Method To Evaluate Servicing Feasibility 66 4.1 Previous Servicing Decision Method . 66 4.2 Expected Value Method . 67 4.3 New Servicing Decision Method . 69 4.4 Satellite Information Required For New Method . 70 5 Database Development 71 5.1 Spacecraft Information Database . 72 5.1.1 Spacecraft Identification Scheme . 72 5.1.2 Sources . 73 5.1.3 Fields . 74 5.2 Database of On-Orbit Spacecraft Failures . 79 5.2.1 Failures Identification Scheme . 79 5.2.2 Sources . 80 5.2.3 Fields . 80 6 Satellite Trends 82 6.1 Commercial Geosynchronous Communications Satellites . 82 6.2 Transponders Per Commercial Geosynchronous Communications Satel- lite..................................... 84 6.3 Total Commercial Geosynchronous Communications Satellite Transpon- ders .................................... 85 6.4 Bandwidth Per Transponder . 86 6.5 Stabilization Of Commercial Geosynchronous Communication Satellites 88 vii 6.6 Geosynchronous Communication Satellite Buses . 90 6.7 Commercial Geosynchronous Communications Satellite Design Life . 92 6.8 Bandwidth-Design Life Trends . 93 6.9 Failure Rate . 96 7 On-Orbit Servicing Opportunities 99 7.1 Launches And Payloads . 99 7.2 Economic Impact Of On-Orbit Satellite Failures . 102 7.3 Spacecraft Failure Servicing Opportunities . 105 7.3.1 Wrong Orbit . 105 7.3.2 Deployment Problems . 112 7.3.3 Component Failures . 112 7.3.4 Fuel Depletion . 116 7.3.5 Other Failures . 116 7.3.6 Spacecraft Family Anomalies . 119 7.3.7 Failed Spacecraft Relocation . 122 7.3.8 Observations Concerning Serviceable Failures . 126 7.4 Spacecraft Lifetime Extension . 129 7.4.1 Relocation . 129 7.4.2 Refueling . 137 7.4.3 Consumables Replenishment . 140 7.4.4 Preventative Maintenance . 141 7.4.5 Spacecraft Upgrade . 142 7.4.6 Optical Surface Maintenance . 142 7.5 Other Services . 144 7.5.1 Inspection . 144 7.5.2 Debris And Failed Spacecraft Relocation . 145 viii 7.6 Summary Of Opportunities . 149 8 Expected Value Of Servicing Market Segments 150 8.1 Chance Node Probabilities . 152 8.1.1 Launch Outcomes . 152 8.1.2 Orbital Transfer Outcomes . 154 8.1.3 Graveyard Transfer Outcomes . 154 8.1.4 Deployment Outcomes . 155 8.1.5 Docking Outcomes . 156 8.1.6 Undocking Outcomes . 156 8.1.7 Refueling Outcomes . 157 8.1.8 Dexterous Repair Outcomes . 158 8.2 Servicing Mission Expected Values . 159 8.2.1 Retirement Maneuver . 159 8.2.2 LEO to GEO Transfer . 167 8.2.3 Relocate In GEO . 171 8.2.4 Refuel . 174 8.2.5 ORU-Like Replacement . 177 8.2.6 General Repair . 180 8.2.7 Deployment Assistance . 181 8.2.8 Deployment Monitoring . 184 8.2.9 Remove Inactive . 187 8.2.10 Health Monitoring . 190 8.3 Summary Of Servicing Mission Expected Values . 190 8.4 Robotic Complexity . 192 9 Demonstration Of The New Method 196 9.1 Servicer Description . 196 ix 9.2 Servicer Operations Concept . 199 9.3 Application Of The New Feasibility Methodology . 204 10 Conclusion 215 10.1 Results . 215 10.1.1 Assessment Of Previous Studies . ..