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AsterAnts: A Concept for Large-Scale Meteoroid Return. Deliver extraterrestrial materials to LEO. Support solar system colonization. Al Globus, MRJ, Inc. Bryan Biegel, MRJ Inc. Steve Traugott, Sterling Software, Inc. NASA Ames Research Center. Near Earth Object Materials.
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AsterAnts: A Concept for Large-Scale Meteoroid Return Deliver extraterrestrial materials to LEO Support solar system colonization Al Globus, MRJ, Inc. Bryan Biegel, MRJ Inc. Steve Traugott, Sterling Software, Inc. NASA Ames Research Center http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Near Earth Object Materials • Mining of large NEOs very difficult to automate • Mining involves large forces • Materials properties are unknown and variable • Capture of small NEO may not require human life support • 10 million - 1 billion 10m diameter NEOs • Far more 1m diameter NEOs http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
NEO Composition • Widely varied, includes large amounts of: • Water • Carbon • Metals, particularly iron • Silicon • Spectral studies don’t agree very well with meteorite analysis http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Detection of 1-meter diameter meteoroids • Current Earth-based optical asteroid telescopes • Smallest found < 10m diameter • Maximum 1m detection distance ~ 106 km • 2,000 to 200,000 within range at any given time • 5-7 hit the Earth each day • Radar required for accurate trajectory and rotation rate http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Solar Sail in Earth Orbit World Space Foundation http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Solar Sailing 1 Net force Photons Sail Sun http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Solar Sailing 2 Orbital velocity Outward spiral Propulsive force Sail Orbital velocity Sun Inward spiral Sail Propulsive force http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Solar sail experience • Solar sailing used by Mariner 10 mission to Mercury for attitude control • Enabled multiple returns to Mercury by reducing control gas consumption • Ground deployment test by World Space Foundation • Zero-g deployment test by U3P in aircraft • Russian Znamia mirror February, 1993 http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Znamia 1993 Guy Pignolet 20 meter diameter spinning mirror deployed from Progress resupply vehicle http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Solar sail meteoroid return • Characteristic acceleration of 1 mm/s2 produces 1.3 km/s delta-v per month • 170-182 meters square sail for 500 kg NEO return at 0.25 mm/s2 characteristic acceleration • Once design is refined, mass production of AsterAnts spacecraft • ?NASA build first one open source, then pay for meteoroid materials by the ton? http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Solar sail geosynchronous slot generation • Continuous thrust pulls geosynchronous orbit out-of-plane • Communications satellites require 2-3 degree spacing • Space manufactured sails required for this spacing • Approximately $2 billion direct broadcast orbital real estate over North America http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
GeoStorm • Double solar storm warning time • Storms disrupt power and communications • Sail • 67 m square • 133kg (19.6g/m2) • 0.274 mm/sec2 NOAA http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Summary • Capture ~1 m diameter NEOs (Near Earth Objects) • Return to LEO (Low Earth Orbit) • Solar sails for propulsion • Start with one small spacecraft, scale up with copies • Early returns have scientific value, later materials for construction and resupply http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html
Conclusion • Benefits • small down payment (one small spacecraft) • scales by mass production • missions can probably be automated • no consumables • Challenges • 1m NEO detection difficult • solar sails have little flight experience • geosynchronous applications require space manufactured sails http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html