Numerical Study on Low-Velocity Impact Between Asteroid Lander and Deformable Regolith

Investigating the impact process between the hopping lander and the regolith surfaces is of great significance for the in situ asteroid explorations. The high-efficiency description of the regolith-interaction dynamics of the lander remains to be analyzed. This paper presents a new method for effectively simulating the six-degree-of-freedom motion of the lander when it impacts the regolith at a low velocity. The Bekker terramechanics theory is utilized for calculating the impact force and torque, considering the notable deformable characteristic of the regolith. Deformation of the regolith surfaces is tracked to simulate the formation of the impact crater. Parametric simulations are implemented to verify this method by varying the regolith physical properties and the initial lander state, respectively. The velocity and angular velocity of the lander are utilized as indicators for comparing the hopping dynamics. Energy dissipation is discussed by calculating the restitution coefficients of different contact scenarios.