Contact Motion on Surface of Asteroid

Abstract

A comprehensive method for modeling the motion of a spherical pod at the surface of an asteroid is presented. Using triangular faceted surfaces, the largest features of the asteroid (global shape, monoliths, and large boulders) are modeled. The presence of smaller rocks is accounted for using a stochastic model of rock generation and collision. The contact dynamics on regolith or harder surfaces, including multiple contact points situations, are described. The force, torque, and coefficient of rolling resistance are introduced, explained, and estimated. Finally, this model is applied to a hypothetical deployment case on asteroid Itokawa. The numerical simulations show landing time around 5 h, with the main landing basin located in Muses Sea. It also proves the importance of each and every level of detail of the asteroid model for an accurate understanding of asteroid surface motion and the effective design of practical deployment strategies.