Electrostatic Sampler for Large Regolith Particles on Asteroids

The authors have developed an electrostatic sampler for the reliable and autonomous collection of regolith particles on asteroids. The sampler, which employs Coulomb and dielectrophoresis forces to capture regolith particles and transport them to a collection capsule, can collect a lunar regolith simulant containing particles of various sizes less than approximately 1.0 mm in diameter in a low-gravity environment. However, there might be large particles with diameters of 1.0 mm or larger on asteroid surfaces. The authors conducted a numerical calculation and a model experiment to confirm whether the sampler can collect particles larger than 1.0 mm in diameter in a low-gravity environment. The numerical calculation, performed using the distinct element method, predicted the effect of the particle diameter on the sampler performance, indicating that particles 1.0 mm in diameter or larger could be successfully sampled in a low-gravity environment. Glass particles 2 mm in diameter were experimentally sampled in a 0.01g environment reproduced by a parabolic aircraft flight, and rocks 4 mm in diameter were agitated under 0.01g and successfully sampled under microgravity.