Rebound Suppression Mechanisms of Particle-Filled Flexible Shells for Small Body Landings
Tongge Wen, Xiaoyu Yang, Sudeshna Roy, Thorsten Pöschel, Xiangyuan Zeng
TL;DR
In microgravity environments ($g \approx 10^{-3}-10^{-5}$), landers risk rebound during touchdown. The paper develops a coupled flexible shell–particle framework by discretizing the shell as a triangular-mesh spring-mass network and fully resolving granular collisions to study energy transfer and dissipation. The results show that flexible shells dissipate $>90\%$ of impact energy through shell–particle coupling, outperforming rigid shells that rely on particle–particle collisions and exhibit larger deformations. These findings inform passive damping strategies for small-body missions and advance understanding of energy dissipation in coupled shell–granular systems.
Abstract
The extremely weak gravity on small bodies makes landers prone to rebound and uncontrolled drift. To mitigate this, the Hayabusa2 mission employed a particle-filled flexible shell, but the coupled dynamics of shell deformation and internal particle dissipation remain unclear. We develop a computational model representing the flexible shell as a spring-mass network and fully resolve particle collisions, friction, and interactions with granular beds. Results show the flexible shell-granule system dissipates over 90 percent of impact energy, far exceeding rigid shells. Energy loss arises from shell-particle coupling, with the particle filling ratio dominating. Impacts on rigid planes produce large shell deformation, while granular beds limit deformation. Scaling and velocity analyses reveal distinct dissipation regimes. These findings clarify energy transfer mechanisms and inform the design of microgravity impact mitigation devices.