Natural Landing Simulations on Generated Local Rocky Terrains for Asteroid Cubic Lander

Recent missions reveal that rubble-pile asteroids usually have a wide distribution of bare rocks in various scales. The dynamical evolution of a lander interacting with such rough surfaces is still an open problem. This article investigates the influence of the explicitly refined rocky terrains on the natural landing motion of a cuboid asteroid lander. The methodology for constructing the local terrains with centimeter-sized to meter-sized rocks is developed based on manipulating the original polyhedron shape model. Local rocky terrains refined with different-sized rocks (20 cm, 40 cm, 80c m, and 1 m) are generated. Moreover, hypothetical local terrains in different numbers of 1-m-sized rocks are presented to assess their influence on the landing motion. Numerical simulations are performed to characterize the dynamical behavior of the lander in rocky terrains. The distributions of the first and second touchdown positions, the transfer time, and the locomotion distance are taken as the three key indicators for examining the motion difference in these rocky terrains. The mechanism for the landing motion is analyzed by considering the collision slope. The results are expected to provide guidelines for the lander deployment and the path planning of a rover on rocky asteroids.