AsterAnts: A Concept for Large-Scale Meteoroid Return

1. 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

2. 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

3. 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

4. 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

5. Solar Sail in Earth Orbit World Space Foundation http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html

6. Solar Sailing 1 Net force Photons Sail Sun http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html

7. 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

8. 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

9. Znamia 1993 Guy Pignolet 20 meter diameter spinning mirror deployed from Progress resupply vehicle http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html

10. 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

11. 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

12. 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

13. 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

14. 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