Unique Abilities of Hopper Spacecraft to Enable National Objectives for Solar System Exploration
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UNIQUE ABILITIES OF HOPPER SPACECRAFT TO ENABLE NATIONAL OBJECTIVES FOR SOLAR SYSTEM EXPLORATION EPHRAIM ROBERT LANFORD B.S. Engineering Harvey Mudd College, 2006 Submitted to the Engineering Systems Division and the Department of Aeronautics and Astronautics in partial fulfillment of the requirements for the degrees of MASTER OF SCIENCE IN TECHNOLOGY AND POLICY and MASTER OF SCIENCE IN AERONAUTICS AND ASTRONAUTICS at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY February 2011 © 2011 Massachusetts Institute of Technology. All rights reserved. Signature of author: Technology and Policy Program Department of Aeronautics and Astronautics January 27, 2011 Certified by: Jeffrey A. Hoffman Professor of the Practice of Aeronautics and Astronautics Thesis Supervisor Certified by: John Danis Group Leader, Mission Architectures and Applications Charles Stark Draper Laboratory Accepted by: Dava J. Newman Professor of Aeronautics and Astronautics & Engineering Systems, MacVicar Faculty Fellow Director of Technology and Policy Program Accepted by: Eytan H. Modiano Associate Professor of Aeronautics and Astronautics Chair, Graduate Program Committee, Department of Aeronautics and Astronautics 2 UNIQUE ABILITIES OF HOPPER SPACECRAFT TO ENABLE NATIONAL OBJECTIVES FOR SOLAR SYSTEM EXPLORATION Ephraim Robert Lanford B.S. Engineering Harvey Mudd College, 2006 Submitted to the Engineering Systems Division and the Department of Aeronautics and Astronautics on January 27, 2011 in partial fulfillment of the requirements for the degrees of Master of Science in Technology and Policy and Master of Science in Aeronautics and Astronautics at the Massachusetts Institute of Technology ABSTRACT In comparison with conventional and other conceived approaches, hopper spacecraft offer unique advantages in exploring Solar System objects beyond Earth. The present work began with a survey – based on documents from the White House, Congress, NASA, and the international planetary science community – of exploration plans and objectives in the United States. The results are presented, and lead into a representative description of goals that might be enabled by hoppers. Relevant hopper attributes are then described in comparison to other vehicle types, and these vehicle characteristics are mapped to the exploration goals to show how hoppers can facilitate achievement of policy and science objectives. Specific examples are examined by formulating and analyzing a demonstrative and timely variety of model missions on Earth’s Moon, Mars, and Saturn’s moon Titan. These analyses use models for both hovering and ballistic hops to produce realistic values for hopper performance including mass, fuel consumption, trajectory characteristics, and basic spacecraft subsystem characteristics. In sum, planetary hopper technology is not for every mission, but generally offers paradigm- changing mobility and flexibility for small additional mass or development costs. Mission planners should evaluate hoppers for suitability to their exploration goals. Policy recommendations are offered toward this purpose. Thesis Supervisor: Professor Jeffrey A. Hoffman Professor of the Practice MIT Department of Aeronautics and Astronautics Thesis Advisor: John Danis Group Leader, Mission Architectures and Applications Charles Stark Draper Laboratory 3 Acknowledgements I would first like to thank my thesis advisor Jeff Hoffman for his guidance and relaxed but demanding demeanor. John Danis, my Draper Laboratory Fellow advisor, deserves the next mention for his profuse helpfulness and enthusiasm for my work. Draper Laboratory as a whole has been very generous and supportive of my research. Bobby Cohanim has also been critical to my progress, success, and sanity; I thank him for his assistance and friendship. From even before my involvement with hoppers, Phillip Cunio has been a stimulating and insightful collaborator. Beyond these, I would like to thank the entire Talaris team at MIT for providing me with ideas, aid, and a fulfilling research project. Next, my colleagues Dan Fulcoly, Ben Corbin, Akil Middleton, and Wendelin Michel all offered advice and contributed to the analytical portions of this thesis. Outside of the aerospace and astronautics world at MIT, my home has been the Technology and Policy Program. For my happy time there I have first to thank Sydney Miller, Frank Field, Ed Ballo, and Dava Newman, for bringing me in, giving me the program I was really looking for, and helping me with the details along the way. In that realm of details, I could not have managed without the helpful people scattered in financial and administrative offices across the Institute. I am also indebted to the MIT Space, Policy, and Society Group, where I began my work space policy, and the fine people in the Space and Science Branch at the Office of Management and Budget who allowed me to intern there one summer. Above all I must express my gratitude to my friends in Cambridge and elsewhere, who have made my time here immensely rewarding, and my family, who got me off to a fine start and have been great comrades ever since. Finally, thanks to Daft Punk for writing the soundtrack to the homestretch of my master’s student career. 4 Table of Contents Acknowledgements ............................................................................................................. 4 Table of Contents ................................................................................................................ 5 List of Figures ...................................................................................................................... 7 List of Tables ....................................................................................................................... 9 Chapter I: Introduction ................................................................................................ 11 I.1. Introduction........................................................................................................ 11 I.2. Description of Sections to Follow ....................................................................... 11 I.3. Background ......................................................................................................... 12 1.3.1 Hopper definition ........................................................................................ 12 1.3.2 History of hoppers ...................................................................................... 12 1.3.3 Project Talaris ............................................................................................. 13 I.4. Methodology ...................................................................................................... 14 1.4.1 The Logic and Process ................................................................................. 14 1.4.2 “Hoptimizer” Model for Hovering Hops ..................................................... 15 1.4.3 BallisticHop Model for Ballistic Hops .......................................................... 21 Chapter II: Objectives for Solar System Exploration ..................................................... 30 II.1. Policy Objectives ................................................................................................ 30 2.1.1 How Solar System Exploration Policy Works .............................................. 30 2.1.2 Important Issues in Planetary Exploration Policy ....................................... 37 2.1.3 Policy Objectives Summary and Outlook .................................................... 42 II.2. Science Objectives .............................................................................................. 43 2.2.1 Sources of Exploration Science Objectives ................................................. 43 2.2.2 Fundamental Questions that Underpin Solar System Exploration ............. 44 2.2.3 Solar System Destinations and Related Goals ............................................ 48 2.2.4 Science Objectives Summary ...................................................................... 53 Chapter III: Matching Vehicle Attributes to Exploration Objectives ............................. 54 III.1. Planetary Exploration Vehicles and Their Attributes ..................................... 54 III.2. Hopper Attributes ........................................................................................... 56 III.3. Destination and Mission Attributes ................................................................ 60 III.4. Vehicle Attributes Mapped to Exploration Objectives ................................... 63 3.4.1 Mapping Hoppers to Destination and Mission Attributes .......................... 63 3.4.2 Mapping Hoppers to Policy Objectives ....................................................... 65 3.4.3 Mapping Hoppers to Science Objectives .................................................... 65 III.5. Chapter Summary ........................................................................................... 68 Chapter IV: Model Missions ........................................................................................... 70 IV.1. Introduction .................................................................................................... 70 IV.2. Earth’s Moon .................................................................................................. 71 4.2.1 A Hopper to Emplace the International Lunar Network? ........................... 72 4.2.2 Hopping in and out of Permanently Shadowed Regions on the Moon ...... 79 4.2.3 Lunar Pits....................................................................................................