Orbital Drag Near Small Bodies Due to Lofted Fines from Surface Activity

Recent exploratory missions have revealed that small bodies are more granular and dusty than previously expected. As a result of landings, mining, impacts, or other natural phenomena, bodies with negligible atmospheres such as moons and asteroids may experience an exospheric environment abundant in lofted fines. Significant quantities of these may interfere with the nominal trajectories of spacecraft in low orbits. This paper applies data collected from remote sensor and direct sample collection to approximate the density of atmospheric fines in three environments: high-velocity lunar fines generated during landings, the coma of active comets, and cryovolcanic plumes from the Saturnian moon Enceladus. It also investigates the threshold of activity that would induce concerns about a spacecraft's nominal mission. Coupled motion of spacecraft navigation and control is expressed in SE(3).