Comparison of two particle charging experiments for testing the JSC Mars-1 Martian regolith simulant against man-made materials

NASA has great interest in testing the electrostatic charging of various materials due to the saltation process near the surface of Mars. As wind blows over the Martian regolith, particles are picked up, travel over a distance, and then fall back to the surface. These moving particles collide with each other and with any other materials present giving rise to a triboelectric charge transfer. Variables involved in this charge transfer include the number of particles, the frequency of collisions, and the particle velocities. It is necessary to know the extent of charging of man-made materials in this process in order to better plan future Mars missions. Two different methods for creating frictional charging between the regolith simulant and the materials in question are described. The first method utilizes a deflection board apparatus. The second uses a shaker box apparatus. The benefits and drawbacks of each experimental approach are listed. Some experimental data obtained through each method is provided but further study is required to fully characterize these charging processes.