Hop Reachable Domain on Irregularly Shaped Asteroids

Abstract

The hopping rover is a promising solution for small celestial body surface mobility. How to predict its locomotion and landing area is challenging when considering the complex dynamical environment and rough terrain. In this study, a new concept of hop reachable domain is proposed to evaluate the surface mobility of a hopping rover treated as a point mass. The two key velocities, i.e., the liftoff velocity and the escape velocity, are derived in detail based on surface dynamical equations, respectively. Numerical simulations are performed with their applications to two representative small bodies, i.e., 101955 Bennu and 67P/Churyumov–Gerasimenko. The influence of local terrain on the liftoff event is investigated in a parametric way. The single-hopping reachable domain and natural-evolution reachable domain are obtained and compared by presenting their characteristics. Parametric studies on these two kinds of hop reachable domain are carried out by varying initial position and velocity vectors. The influence of the asteroid self-rotation on the locomotion of a rover is also analyzed with numerical simulations.