Magnetic Sampler for Regolith Particles on Asteroids

Abstract

A magnetic sampler for future sample return missions on asteroids was developed. The sampler had a simple configuration, consisting of a solenoid coil, direct current (DC) power supply, and switching circuit, and the sampling was conducted using the coil gun mechanism. The sampler did not require mechanical moving parts, gas, or liquid, and its control was simple; thus, it was reliable for use in a space environment. The authors analyzed the particle motion in a magnetic field on Earth and in space environments; the sampler performance was evaluated by numerical calculations on the basis of the distinct element method and experiments in air and vacuum environments. The results of numerical calculations and experiments were consistent qualitatively with the analytical calculations. The magneto-motive force and its applied time mutually affected the dynamics of particles. The magnetic interaction of particles in the magnetic field also affected the sampler performance. Moreover, the sampler performance in vacuum and a microgravity of 0.00001g was better than that on Earth owing to the absence of air drag and small gravitational force.