Thermal Mining of Ices on Cold Solar System Bodies NIAC Phase I Final Report February 2019 George Sowers 1 Purpose This is the final report of the NASA Innovative Advanced Concepts (NIAC) Phase I study: Thermal Mining of Ices on Cold Solar System Bodies. It is submitted as partial fulfillment of the obligations of the Colorado School of Mines (CSM) under grant number 80NSSC19K0964. 2 Table of Contents List of Figures 5 List of Tables 9 1.0 Executive Summary 10 2.0 Introduction 15 3.0 Solar System Survey of Thermal Mining Targets 18 3.1 Potential Thermal Mining Targets 19 3.2 Thermal Mining Beyond the Moon 32 4.0 Thermal Mining Mission Context: Lunar Polar Ice Mining 34 4.1 Lunar Polar Ice Distribution Analysis 36 4.2 System Architecture 39 4.3 Functional Analysis 42 4.4 Ice Extraction Subsystem 46 4.5 Power Subsystem 53 4.6 Deployment and Setup 55 4.7 Operations 59 4.8 Mass and Cost Estimates 66 4.8.1 Subsystem Mass Estimates 66 4.8.2 Total Mass 70 4.8.3 Subsystem Cost Estimates 71 4.8.4 Total Cost 74 4.9 Business Case Analysis 76 4.9.1 The Propellant Market 76 4.9.2 Business Case Scenarios 80 4.9.3 Business Case Results 83 4.9.4 Comparison to Previous Analysis 87 5.0 Proof of Concept Testing 91 5.1 Testing Objectives and Approach 91 5.2 Icy Regolith Simulants 91 5.3 Block 1 Testing 95 5.3.1 Block 1 Apparatus 95 5.3.2 Block 1 Methodology 96 5.3.3 Block 1 Results 97 5.4 Block 2 Testing 105 5.4.1 Block 2 Apparatus 105 5.4.2 Block 2 Methodology 105 5.4.3 Block 2 Results 105 5.5 Test Conclusions 106 6.0 Summary and Conclusions 115 6.1 Bulletized Summary 115 6.2 Conclusions 116 6.3 Recommendations for Future Work 118 7.0 References 121 8.0 Appendix A: Solar System Catalogue 129 9.0 Appendix B: Acronym List 132 3 Acknowledgements This report was prepared by George Sowers, Ross Centers, David Dickson, Adam Hugo, Curtis Purrington, and Elizabeth Scott. It was reviewed by Chris Dreyer and Angel Abbud-Madrid. Cover art is by Matt Olson showing the ice extraction system in a lunar permanently shadowed region (PSR). 4 List of Figures 1.0 Executive Summary Figure 1.1. Ice extraction on the Moon. 10 Figure 1.2. The inner solar system. 11 Figure 1.3. Ice extraction system concept. 12 Figure 1.4. CSM medium cryo-vacuum chamber. 13 2.0 Introduction Figure 2.1 Moving from exploration results to a proven reserve. CRIRSCO, 2012. 15 Figure 2.2. Heat applied to an icy regolith simulant sample under cryogenic vacuum conditions. 16 Figure 2.3. Thermal Mining based ice extraction system on the Moon. 17 3.0 Solar System Survey of Thermal Mining Targets Figure 3.1. The inner and outer Solar System. 18 3.1 Potential Thermal Mining Targets Figure 3.2. Mercury, with detected water ice in yellow. 19 Figure 3.3. Mars, widespread glacial ice in blue, detected by MRO radar passes in yellow. 20 Figure 3.4. Mars, example of steep scarps with visible water ice. 20 Figure 3.5. Comet 67P (top right), close-up of two areas of exposed water ice (bottom left). 21 Figure 3.6. 24 Themis, approx. orbit of asteroid (red). 22 Figure 3.7. Ceres, approx. true-color image. 22 Figure 3.8. 65 Cybele, approx. orbit of asteroid (blue). 23 Figure 3.9. Ganymede, surface and subsurface layers, visualized. 23 Figure 3.10. Calisto, approx. true-color image. 24 Figure 3.11. Europa, side view of ice and hydrothermal vents. 24 Figure 3.12. Jupiter Trojans, two groups of Trojan objects (green). 24 Figure 3.13. Titan, exposed water ice on the surface (blue). 25 Figure 3.14. Iapetus, leading hemisphere (left), trailing hemisphere (right). 25 Figure 3.15. Dione, trailing hemisphere (left), leading hemisphere (right). 26 Figure 3.16. Tethys, trailing hemisphere (left), leading hemisphere (right). 26 Figure 3.17. Enceladus, side view of ice and hydrothermal vents. 27 Figure 3.18. Mimas, image of moon (left), heat map of daytime temperatures (right). 27 Figure 3.19. Phoebe, the irregular moon. 28 Figure 3.20. Hyperion, seen here with its porous and sponge-like exterior. 28 Figure 3.21. Chariklo, Hubble Space Telescope image of the largest centaur. 28 Figure 3.22. Titania, Voyager 2 image of the largest moon of Uranus. 29 Figure 3.23. Triton, Voyager 2 image of the largest moon of Neptune. 29 Figure 3.24. Relative locations of Neptune’s L4 and L5 Trojans. 30 Figure 3.25. Relative sizes, colors, and albedos for some of the large Trans-Neptunian objects. 30 Figure 3.26. Orcus & moon Vanth, Hubble Space Telescope image of the dwarf planet Orcus (center) and its moon (center-bottom). 31 5 Figure 3.27. Pluto & moon Charon, image of Pluto (left), enlarged image of Pluto’s moon Charon (right). 31 Figure 3.28. Eris & moon Dysnomia, Hubble Space Telescope image of the most massive dwarf planet (center) and its moon (center-left). 32 4.0 Thermal Mining Mission Context: Lunar Polar Ice Mining Figure 4.0.1. Ice exposures at the North Pole and South Pole of the Moon. 34 Figure 4.0.2. Resource exploration (prospecting) roadmap. 35 4.1 Lunar Polar Ice Distribution Analysis Figure 4.1.1. Initial results from the CSM model. 37 Figure 4.1.2. Comparison of ice concentration vs depth for three lunar terrain types. 38 4.2 System Architecture Figure 4.2.1. High-Level Space Supply Chain. 39 Figure 4.2.2. Propellant Production Architecture. 40 Figure 4.2.3. Ice extraction concept. 41 Figure 4.2.4. Ice extraction subsystem. 41 Figure 4.2.5. IHOP Water Processing Overview (Paragon Corp.) 42 4.3 Functional Analysis Figure 4.3.1. Capture tent functional tree. 43 Figure 4.3.2. Cold trap hauler functional tree. 44 Figure 4.3.3. Secondary optics functional tree. 45 4.4 Ice Extraction Subsystem Figure 4.4.1. The Capture Tent. 46 Figure 4.4.2. Capture Tent product tree. 47 Figure 4.4.3. Capture tent legs in lowered tent (left) and raised tent (right) positions. 49 Figure 4.4.4. Cold trap hauler. 50 Figure 4.4.5. Cold trap hauler product tree. 50 Figure 4.4.6. Secondary optics. 51 Figure 4.4.7. Secondary optics product tree. 52 Figure 4.4.8. Secondary optics mirror geometry. 52 4.6 Deployment and Setup Figure 4.6.1. The Vulcan/Centaur rocket. 55 Figure 4.6.2. Centaur 5. 55 Figure 4.6.3. XEUS, the Centaur 5 stage equipped with a landing kit. 56 Figure 4.6.4. Deployment and setup sequence. 57 4.7 Operations Figure 4.7.1. Overall process flow. 59 Figure 4.7.2. Ice collection and transport flow. 59 Figure 4.7.3. Notional mining site map. 60 Figure 4.7.4. Tent placement pattern. 60 Figure 4.7.5. Ice hauler transit time. 61 6 Figure 4.7.6. Ice hauler duty cycle. 62 Figure 4.7.7. Tent repositioning flow. 63 Figure 4.7.8. Capture Tent and ice hauler in the towing configuration. 63 Figure 4.7.9. The capture tent being moved across the PSR. 64 4.8 Mass and Cost Estimates Figure 4.8.1. Propellant production system architecture. 66 Figure 4.8.2. Subsystem mass comparison. 71 Figure 4.8.3. Development and production cost by subsystem. 73 4.9 Business Case Analysis Figure 4.9.1. Benefits of refueling with space sourced LO2/LH2 propellants. 77 Figure 4.9.2. ∆V map of cislunar space. 77 Figure 4.9.3. Propellant prices in cislunar space. 78 Figure 4.9.4. Propellant production program plan. 83 Figure 4.9.5. Cumulative cash for the Propellant Production Company. 84 Figure 4.9.6. Scenario 1. IRR sensitivity with propellant price and non-recurring cost. 85 Figure 4.9.7. Scenario 2. IRR sensitivity with propellant price and NASA investment. 86 Figure 4.9.8. Scenario 3. IRR sensitivity with propellant price and NASA investment. 86 Figure 4.9.9. Cumulative cash for NASA. 87 5.2 Icy Regolith Simulants Figure 5.2.1. Lunar Highlands Simulant –1 Spec Sheet, Exolith Labs. 92 Figure 5.2.2. Granular Icy Regolith Simulant, 12% Water Weight. 93 Figure 5.2.3. Sample Container submerged in LN with LN feed through. 93 Figure 5.2.4. ‘Mud Pie’ icy regolith simulant, 12% water weight. 94 Figure 5.2.5. Frost Layer Production, Simulant and Container at 77K. 94 5.3 Block 1 Testing Figure 5.3.1. Left: Adiabatic Boundary Condition, Right: Isothermal Boundary Condition. 95 Figure 5.3.2. View from Vacuum Chamber port during an adiabatic boundary test. 96 Figure 5.3.3. Mud Pie Surface Condition after a 5-hour test. 97 Figure 5.3.4. Cross-Section diagram of Mud Pie Icy Regolith physical analysis results. 98 Figure 5.3.5. Temperature profile response of various ice grain configurations at depth of 2cm with a 12wt% water. 98 Figure 5.3.6. General physical subsurface structure of granular fine simulant with isothermal boundary condition with an initial water of 5.6wt% or 12wt%. 99 Figure 5.3.7. General physical subsurface structure of granular fine simulant with adiabatic boundary condition with an initial water of 5.6wt% or 12wt%. 100 Figure 5.3.8.