Influence of the Lander Size and Shape on the Ballistic Landing Motion

This article investigates the ballistic landing motion and final distribution of the landers in different sizes or shapes near the small celestial body. Three typical shapes, including cubic, cuboid, and cylindrical, are considered for the landers deployed to a tri-axial ellipsoid model. The Polygonal Contact Model (PCM) is used to detect the contact/collision, where the Hertz model is applied to calculate the continuous contact force. Different-sized cubic landers (in the edge length of 20, 30, 40, and 50 cm) are numerically simulated to examine how the lander size influences its dynamics. The landing motion of the cuboid- and the cylinder-shaped landers are then analyzed in the same technique. The heights of these asymmetrical landers are assumed to be 25, 30, and 35 cm, respectively, to illustrate the shape effect. Monte Carlo simulations are implemented for various landers to account for the surface motion randomness. The final dispersion, the outgoing velocity after the collision, the horizontal transfer distance, and the settling time are taken to be critical indicators for discussing the landing behavior, which can provide implications for the probe design of future missions.