the understanding of low velocity surface-lander interactions is critical for missions with lander components and influences lander deployment and sample return strategies. Phenomenological models have been proposed to account for experimental measurements of penetration depth of spherical projectiles impacting granular materials in a gravitational field and at normal incidence (e.g., @uehara03 [@tsimring05; @ambroso05; @katsuragi07; @goldman08; @katsuragi13; @murdoch17]). For normal impacts (e.g., @uehara03 [@tsimring05; @ambroso05; @goldman08; @katsuragi13; @murdoch17]), and recent oblique impact experiments [@bester19], most experimental studies have modeled the granular medium with an empirical force law that includes a hydrodynamic drag term proportional to the square of the velocity, which dominates at higher velocity and so at deeper penetration, and a term which accounts for a depth dependent static resistance force which dominates at lower speeds and shallow penetration depths. However a higher velocity projectile at grazing incidence may not penetrate deeply and would still feel a hydrodynamic-like drag. Horizontal motion in granular media can cause lift [@ding11; @potiguar13]. Thus the empirical models primarily developed for normal impacts need to be modified in order to account for impacts at grazing angles.

Phenomenological models for ricochet in sand or water [@birkhoff44; @johnson75; @daneshi77; @soliman76; @bai81] predict a velocity dependent critical angle 