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Sampling of Regolith Particles from Asteroids Utilizing Alternative
Electrostatic Field
Hiroyuki KawamotoWaseda University, Tokyo
June 19, 2013; Low-Cost Planetary Missions Conference (LCPM-10) @Caltec
• After the success of the HAYABUSA (JAXA), additional projects on sample returning from asteroids are being planned in Japan and the US. Because HAYABUSA hardly succeeded in obtaining a sufficient sample by the bullet firing technique, a more reliable technology is required
• We are developing a new sampling system that employs electrostatic force
• This system is simple, virtually zero-power, has no mechanical moving parts, and suitable for autonomous operation in space
Substantial amount of regolith can be captured even at one-
second operation
captured regolith m
g
1 second
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Sampling on Earth
10 kVp-p, 10 Hz
1.5 mm
observed calculated (DEM)
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Experiment in Zero-G Environment
parabolic flights by JAXA
150 mm
capture
conveyer
capsule
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1 G zero-G
Effect of Gravity
In zero-G: Regolith can be captured at high altitudeLarge particles can be captured
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• 900 mg regolith was captured only in one-second operation
• Large particles was captured
Captured Particle Size
1000
volume
%
0.5
0.4
0.3
0
0.2
0.1
100101
particle diameter mm
captured in 0-G
captured in 1-G
initial
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Performance on Small Asteroid
observed in
• zero-G• w/ air drug
calculated in
• zero-G• w/ air drug
calculated in
• zero-G• w/o air drug
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iron
ice ice mixed with lunar regolith
glass
Sampling for Varied Particles
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Power Consumption
0
0.2
0.4
0.6
0.8
0 2 4 6 8 10
applied voltage kVp-p
power m
W
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Merits of This System
■■■■ Operation in Space
The performance of this system will be much better in space than on the Earth because of low gravity and higher threshold voltage against insulation breakdown in vacuum
■■■■ Adaptability for Autonomous Operation
Because the system consumes less power, it can begin the operation before the spacecraft lands on the asteroid, and end the operation after the collection of the regolith is confirmed. Precise timing adjustment is not necessary; therefore, it is suitable for autonomous operation
■■■■ Reliability
The system is highly reliable because it is very simple and because moving parts or firing systems are not necessary