Soil behavior under vehicle action is influenced by a complex interaction of frictional, cohesive, and inertial forces induced in the soil failure zone. Effects of lunar vacuum and gravity on these forces and resulting changes in gross traction and rolling resistance are related to available knowledge in relevant fields and to experiments performed to measure inertial component of soil shear strength under transient loading. It is concluded that these environmental effects on vehicle-soil interaction are cumulative and point toward improved vehicle mobility on the moon, particularly for a critical terrain model consisting of a thick layer of loose dust.
