Strategies for Affordable Human Moon and Mars Exploration by Paul Douglas Wooster B.Sc., Aerospace Engineering (2003) Massachusetts Institute of Technology Submitted to the Department of Aeronautics and Astronautics in Partial Fulfillment of the Requirements for the Degree of Master of Science in Aerospace Engineering at the Massachusetts Institute of Technology February 2007 © 2007 Massachusetts Institute of Technology All rights reserved Signature of Author………………………………………………………………………… Department of Aeronautics and Astronautics February 2, 2007 Certified by………………………………………………………………………………… Edward F. Crawley Professor of Aeronautics and Astronautics and Engineering Systems Thesis Supervisor Accepted by………………………………………………………………………………... Jaime Peraire Professor of Aeronautics and Astronautics Chair, Committee on Graduate Students - 1 - - 2 - Strategies for Affordable Human Moon and Mars Exploration by Paul Douglas Wooster Submitted to the Department of Aeronautics and Astronautics on February 2, 2007 in partial fulfillment of the requirements for the degree of Master of Science in Aerospace Engineering. ABSTRACT The U.S. Vision for Space Exploration calls for NASA to undertake human exploration of the Moon and Mars. This endeavor must be performed in an affordable manner in order to be successful. This thesis outlines a series of affordability strategies that could be considered as part of the Vision for Space Exploration. Analyses of specific options for affordable human Moon and Mars missions along with integrated exploration campaigns are presented. Significant results for lunar missions include recommendations to employ extended pre-descent loiter for sortie missions to more challenging sites and the use of a single launch approach, as opposed to NASA’s current 1.5 launch baseline, for crewed lunar missions. There appears to be significant opportunity for commonality between Moon and Mars exploration systems if appropriate choices are made during system development. Robust Mars missions appear to be achievable with the Earth launch and departure system currently under development by NASA, without the need for investments in advanced propulsion options such as nuclear thermal or electric propulsion. The affordability of the lunar campaign would be enhanced greatly by the use of dedicated cargo flights for lunar outpost deployment, in contrast with NASA’s current plan to incrementally deploy an outpost with crewed flights alone. Thesis Supervisor: Edward F. Crawley Title: Professor of Aeronautics and Astronautics and Engineering Systems - 3 - - 4 - Acknowledgements I would like to thank Professor Edward Crawley for his advice and support throughout my time as a Masters student, in addition to encouraging me to pursue a Masters to begin with. Similarly, I would like to thank NASA for providing the financial support which made this work possible. Much of the work presented in this thesis builds upon work conducted during the Draper-MIT Concept Exploration and Refinement (CE&R) study. As such, I would like to thank the entire CE&R team and in particular the Transportation Architecture group for all of their hard work and dedication. One member of the CE&R team who particularly stood out and with whom I have continued to work since was Mr. Wilfried Hofstetter. Wilfried and I met approximately two and half years ago, and since that time few days have gone by where we have not discussed some aspect of the exploration of space together. It has been a great pleasure working with Wilfried and many of ideas presented in this thesis have been greatly refined through my conversations with him. And finally I would like to especially thank my wife, Meghann, for her inspiration, love, and encouragement for this and all of my endeavors. I love Meghann deeply and cherish every moment with her. - 5 - - 6 - Table of Contents 1 Introduction............................................................................................................... 11 2 Exploration Affordability Strategies......................................................................... 15 2.1 Exploration Affordability Defined.................................................................... 15 2.2 Description of Affordability Strategies............................................................. 17 3 Affordability Considerations for Human Lunar Missions........................................ 28 3.1 Extended Pre-Descent Loiter for Lunar Sortie Missions.................................. 30 3.2 Human Lunar Mission Launch Strategy........................................................... 44 3.3 Descent Stage Commonality across Lunar Landing Use Cases ....................... 51 3.4 Lunar Operational Transportation Architecture................................................ 63 3.5 Lunar In-Situ Resource Utilization................................................................... 79 4 Affordability Considerations for Human Mars Missions ......................................... 86 4.1 Mars Transportation Architecture Pathways .................................................... 87 4.2 Earth Launch and Departure System Design.................................................... 92 4.3 Common Moon-Mars Exploration System Design........................................... 98 5 Exploration Campaign Comparisons...................................................................... 121 5.1 Using the Moon to Prepare for Mars .............................................................. 122 5.2 Campaign Descriptions................................................................................... 123 5.3 Campaign Cost Comparison ........................................................................... 131 6 Conclusion .............................................................................................................. 134 6.1 Significant Findings........................................................................................ 134 6.2 Specific Recommendations............................................................................. 135 Appendix A: Capability Analysis of NASA’s Exploration Launch Vehicles ................ 137 Method for Estimating Performance of NASA’s Ares V Launch Vehicle................. 137 Estimate of Current Ares V Performance for Alternate Missions .............................. 140 References....................................................................................................................... 144 - 7 - List of Tables Table 1. Major ESAS element functions and comparison to Apollo program.............................. 12 Table 2. Categorization of technical affordability strategies......................................................... 18 Table 3. Technical affordability strategies’ tendency on cost elements and benefit..................... 19 Table 4. Programmatic affordability strategies’ tendency on cost elements and benefit. ............. 23 Table 5. Chapter 3 topics and associated affordability strategies.................................................. 28 Table 6. Lunar mission maneuver Delta-V’s and references. ....................................................... 28 Table 7. Approaches to obtain global access with anytime return for LOR missions................... 33 Table 8. Maximum plane changes required as part of global access with anytime return approaches for worst-case lunar landing site................................................................................. 34 Table 9. Approximate Delta-V’s for maneuvers of global access with anytime return approaches for worst-case lunar landing site.................................................................................................... 34 Table 10. Table of top ten science sites from ESAS report........................................................... 42 Table 11. Useful surface cargo capability for crewed missions .................................................... 46 Table 12. Likely LSAM Descent Stage lunar landing use cases................................................... 52 Table 13. LOI Delta-V and CEV mass inputs by mission type..................................................... 53 Table 14. TLI capability by launch strategy.................................................................................. 53 Table 15. Crew Compartment Masses Used in Architecture Analysis. ........................................ 67 Table 16. Additional Payload Masses ........................................................................................... 67 Table 17. Earth Departure Stage parameters................................................................................. 67 Table 18. Service Module parameters........................................................................................... 68 Table 19. Descent Stage parameters.............................................................................................. 68 Table 20. Ascent Stage parameters. .............................................................................................. 68 Table 21. Consumables requirements for low and high closure life support systems................... 80 Table 22. Packaging factors on consumables delivered to the lunar surface. ............................... 81 Table 23. Breakdown of consumables and propellants to be delivered to the lunar surface and resulting maximum benefit from ISRU for a series of scenarios. ................................................. 82 Table 24. Relative benefit of lunar regolith oxygen extraction