Implications of electrostatics and cohesion for asteroid surface exploration

Small regolith particles posed a significant challenge for surface operations during the Apollo program through abrasion of spacesuits and the covering of solar panels. Additionally, the observed lunar horizon glow and unexpected results of the Lunar Ejecta and Meteorites (LEAM) experiment have been attributed to the electrostatically-induced movement of dust grains. Electrostatically-controlled motion of dust grains on asteroids has also been hypothesized given the observed dust ponds filling craters on Eros. Recent improvements in our understanding of the plasma environment near the surface of airless bodies and of the inter-particle cohesion of dust particles have prompted a new model of dust particle motion. Our model is in agreement with experimental results from dust mitigation experiments that attempt to clear dust particles from spacecraft surfaces, indicating that cohesive forces dominate at small particle sizes. Our new understanding of the electrostatic and cohesive forces present in the asteroid and lunar environments provides opportunities for several engineering applications. We propose that electrostatic forces could be exploited in directing the motion of hopping exploration vehicles on the surface of small bodies. Additionally, new sample collection methods that take advantage of the electrostatic sensitivity of small particles could be developed. Surface vehicle mobility will be influenced by the geographic distribution and size range of dust particles. The electrostatic and cohesive forces relevant in the asteroid environment will be described. Potential engineering implications of this model will be discussed.