An Analysis of ICBM Navigation Using Optical Observations of Existing Space Objects by Weldon Barry Willhite B.S. Mechanical Engineering, United States Naval Academy, 2002 SUBMITTED TO THE DEPARTMENT OF AERONAUTICS AND ASTRONAUTICS IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AERONAUTICS AND ASTRONAUTICS AT THE ARCHVE MASSACHUSETTS INSTITUTE OF TECHNOLOGY MASSACHUSETS INSTTUTE. OF TECHNOLOGY JUNE 2004 MAR 2 2 2010 LIBRARIES Copyright @2004 Weldon Barry Willhite. All rights reserved. The author hereby grants to MIT permission to reproduce and to distribute publicly paper and electronic copies of this document in whole or in part. Signature of Author ............................................. Department of Aeronautics Ad Astronautics /' Y?,1j4, 2004 C ertified by ........................................ Richard E. Phillips, Ph.D. Principal Member of the Technical Staff The Charles Stark Draper Laboratory, Inc. Techpical Supervisor C ertified by ......................................... ..... ........ Jo6A E. Keesee, Col, USAF (retired) Senior Lecturer, Department of Aeronautics and Astronautics Thesis Advisor A ccepted by ............................ .......... Edward M. Greitzer, Ph.D. H.N. Slater Professor of Aeronautics and Astronautics Chair, Committee on Graduate Students [This page intentionally left blank] An Analysis of ICBM Navigation Using Optical Observations of Existing Space Objects by Weldon Barry Willhite Submitted to the Department of Aeronautics and Astronautics on May 14, 2004, in partial fulfillment of the requirements for the degree of Master of Science in Aeronautics and Astronautics Abstract This thesis investigates the potential of a space-based navigation concept known as Skymark to improve upon the accuracy of inertially-guided intercontinental ballistic missiles (ICBMs). The concept is to use an optical tracker to take line-of-sight measurements to nearby space objects with known ephemerides to update the state knowledge of the onboard inertial navigation system. The set of existing space objects that would be potentially useful for this application are tabulated, and a simulation determines their availability from realistic trajectories. A follow-on navigation simulation investigates the accuracy improvement potential in terms of Circular Error Probable at impact. Two scenarios are investigated, one in which the Skymark system is an add-on aid-to-inertial-navigation for an existing missile system, and one in which the Skymark system is completely integrated with a new inertial navigation unit. A sensitivity analysis is performed to determine how several performance factors affect Skymark accuracy. Finally, a brief discussion of some operational implementation issues is included. Technical Supervisor: Richard E. Phillips Title: Principal Member of the Technical Staff The Charles Stark Draper Laboratory, Inc. Thesis Advisor: John E. Keesee, Col, USAF (retired) Title: Senior Lecturer, Department of Aeronautics and Astronautics [This page intentionally left blank] Acknowledgements Working on this thesis has been an incredibly enriching experience, and so I am very thankful to the Charles Stark Draper Laboratory for providing the opportunity for me to perform this research and study at M.I.T. I would also like to thank the U.S. Air Force ICBM Systems Program Office and Northrup Grumman Mission Systems for sponsoring my work here at the Draper Laboratory. I am especially indebted to Richard Phillips, my technical advisor, who was always available to answer my multitude of questions and provide exceptional guidance every time I found myself at a standstill. I would also like to express my gratitude to several other members of the Draper staff who have been supporting me in this research endeavor: Jim Shearer, Mary Biren, Bill Robertson, Ron Proulx, and Roy Setterlund. My deepest thanks also are due to Colonel John Keesee, USAF (retired), my academic advisor. His brilliant ideas and expert advice helped to steer this research in the right direction and ensure the thoroughness of this study. I would also like to thank my wife, Jennifer, who has supported me through this entire process. Thank you so much for encouraging me and being interested in my thesis, it has made a mighty difference! Above all, I am thankful to God, who gave me both the ability and the strength to complete this work. Without Him I can accomplish nothing. He is my inspiration, motivation and reason for being. Since ICBM accuracy values are classified, I have made assumptions of current accuracies based on unconfirmed values identified in open source literature. This thesis was prepared at The Charles Stark Draper Laboratory, Inc., under internal project number 88002, contract number SUB HP 10786M8S (SLIN 0034), sponsored by the United States Air Force ICBM Systems Program Office and Northrup Grumman Mission Systems. Publication of this thesis does not constitute approval by Draper or the sponsoring agency of the findings or conclusions contained herein. It is published for the exchange and stimulation of ideas Weldon Barry Willhite [This page intentionally left blank] Contents 1 Introduction 15 1.1 T hesis M otivation ........................................................................................... 15 1.2 The Skymark Concept..................................................................................... 16 1.3 Circular Error Probable and Impact Error Sources......................................... 17 1.4 T hesis O bjectives ........................................................................................... 19 2 Investigation of Satellite Availability 23 2.1 Defining the Qualities of a Suitable "Skymark"........................................... 23 2.2 Extracting the Set of Feasible Space Objects ............................................... 26 2.3 Determining Satellite Availability via Simulation......................................... 30 2.3.1 Trajectory Assumptions .................................................................... 30 2.3.2 Launch Time Assumptions ................................................................ 32 2.3.3 Catalog Propagation........................................................................... 33 2.3.4 Simulation Sequence of Events ........................................................ 33 2.4 Calculating the Instrument Magnitude............................................................ 34 2.5 Satellite Availability Tabulation.................................................................... 37 2.6 Skymark Availability Results ......................................................................... 37 2.6.1 Variations Due to Launch Time......................................................... 38 2.6.2 Limiting Magnitude Effects................................................................ 43 2.6.3 Catalog Sizing Effects......................................................................... 47 2.7 Summary/Conclusions .................................................................................... 52 3 Impact Accuracy Improvement 55 3.1 Operational System Model ............................................................................. 56 7 3.1.1 Skymark as an Aid-to-Navigation for a Current System.................... 56 3.1.2 Skymark as a Next-Generation Navigation System............................ 57 3.2 Sim ulation Inputs ........................................................................................... 58 3.2.1 Inertial Navigation System Error Model................................................ 58 3.2.2 Optical Tracker Characteristics........................................................... 60 3.2.3 Space Object Ephemeris Knowledge.................................................. 60 3.2.4 Space Object Catalog Size .................................................................. 62 3.2.5 Number of Skymark Measurements ................................................. 63 3.3 Sim ulation Flow ............................................................................................. 63 3 .4 R esu lts................................................................................................................ 64 3.4.1 Skymark as a New System.................................................................. 65 3.4.2 Skymark as an Addition to a Current System.................................... 70 3.5 Summary and Conclusions ............................................................................ 75 4 Skymark Sensitivity Analysis 77 4.1 Sensitivity to Tracker Angle Measurement Uncertainty ............................... 78 4.2 Sensitivity to Tracker Limiting Magnitude.................................................... 81 4.3 Sensitivity to Skymark Ephemeris Knowledge ............................................. 83 4.4 Sensitivity to Space Object Catalog Size...................................................... 85 4.5 Conclusions Obtained From Individual Sensitivities .................. 87 4.6 Skymark as an Addition to a Current Missile............................................... 90 4.7 Relationships Between Parameters and Cost.................................................. 91 4.8 Sensitivity to Number of Skymark Measurements ......................................... 95 5 Conclusions and Implementation Issues 101 5.1 Summ ary of C onclusions................................................................................. 101 5.2 Operational Implementation Issues.................................................................