Session 2: Extraterrestrial Prospecting Chair: Professor Michael F. A’Hearn
Prof. Michael A’Hearn, University of Maryland, Department of Astronomy _Water vs. Rocks: Resources for Earth or for Exploration?_ /– Reachable resources – NEOS vs other targets /— No gravity well /– Example – An Aten class asteroid /– NEOs: /— many different types of rocky asteroids /— ~15% are low in albedo – probably dormant comets /— Cometary NEOs – 50% water, organics like CO, CO2, half are “CHON” – relatively stable organic solids /— Nitrogent is strongly depleted relative to cosmic /– Where is ice in comets? /— Ices is on surface but most water is not from that ice. /— Most ice is below surface by 1-3 skin depths – definitely < 2m /-- Deep Impact impactor on comet sent water vapor quickly into view /-- Could return the whole cometary NEO to where it is needed. /-- Mining properties: /--- Extremely porous, soft and weak material /--- Won't sink into it because the gravity is so low. /--- Thermal conductivity is very low ?Brad Blair, Space Studies Institute, and Prof. Leslie Gertsch, University of Missouri-Rolla _Mining Methods for Asteroid Utilization_ /-- Mining is an economic activity, not just a technical task /-- Customer profiles /--- Commodity type: PGMs for terrestrial markets, Volatiles for propellants, metals for structures, etc. /--- Consumer type: supporting and building settlements /-- Constraints - astrodynamics, environmental conditions, launch systems, available energy, maintenance & repair, etc. /-- Asteroid mining process steps: /--- mine development and site preparation /--- extraction /--- mine design process /-- Developing of mining methods for asteroids /--- Bag & boil /--- Magnetic rake /--- Divide and deliver /--- Put into earth orbit /--- etc /-- Several technologies can typically be applied to get similar capability /-- Some in space capabiliteis have already been demonstrated: /--- scooping of regolith samples on Moon & Mars /--- Coring & drilling on Moon /--- Grinding of rock samples on Mars, /--- etc. /-- Planetary defense strategies /--- Mining info leads to knowledge on how to defend against NEOs, e.g. determin an asteroid's structure. /-- Partner ISRU with planetary defense ?Mark Sonter, Asteroid Enterprises Pty Ltd _Mining Concepts Development for Accessing Asteroid Resources_ /-- About 8000 NEAs now identified /-- growing belief that NEAs contain easily extractable products /-- Dependent on development of in-orbit markets /-- of the NEAs, >3200 are >300m and >800 are > 1km diam /– Asteroids retain deep regolith, heavily fractured, etc. /– A bankable feasibility study must be developed, e.g. mining plan for extractable ore. /– Mining plan and process can often be surprisingly difficult – discusses cases in Australia /– Table of mining methods, most rejected; underground mining with mechanical “mole” accepted /– Examples of terrestrial mines with high value ores /– PGMs value for ~$4000/tone /– Water value ~$1M/ton in LEO /– Assume first material extracted from a NEA will be water.
?Dr. Faith Vilas, University of Arizona, Department of Astronomy and Steward Observatory _Resources from Asteroids: What We Can Expect From What We Know Now_ /– shows this cool graphic of asteroid discovery. /– Composition & mineralogy /– Use spectral analysis to study compositions of surfaces. /– Aqueous alterations hint at water content /– NEAs largely missing water signals /– Evidence of water on 24 Themis /– Ceres long known to have water /– Distant spectal studies not definitive. Asteroid studied by Cassini was much more interesting than appeared from earth. /– Diversity of asteroids will probably be much greater than seems now as seen from earth based studies.
Q&A with all speakers: /– Different views on ratio of robot vs human involvement with the mining. /– Even on earth there is a move towards more robotic utilization /– A very successful mine in New Guinea in 1930s was very remote and difficult to reach but was run by a small company.