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 ~ 10 6 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

Sun Photons

Solar Sailing 1

Net force Sail http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html

Solar Sailing 2

Orbital velocity Outward spiral Propulsive force Sail Sun Inward spiral Orbital velocity 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/s 2 produces 1.3 km/s delta-v per month • 170-182 meters square sail for 500 kg NEO return at 0.25 mm/s 2 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/m 2 ) – 0.274 mm/sec 2 http://science.nas.nasa.gov/~globus/papers/AsterAnts/paper.html

NOAA

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