Design of a Multi-modal Morphing Robot for Asteroid Surface Exploration

ASTRID (Asteroid Shape-shifting Robot for Intelligent Discovery) is a two-wheeled novel robotic system designed for crater exploration on small planetary bodies. ASTRID's dual hopping and roving mobility system enables energy-efficient long-range locomotion, and precise short-range maneuvers in microgravity. The robot is lowered into asteroid craters in a ball configuration via a tether attached to the mission lander. Upon reaching the crater slope, ASTRID splits into two wheels, morphing their shape and diameter to grip loose soil and perform hops by propelling itself at controlled angles. Once it reaches proximity to its target, it switches to roving. Alternating between both modes of locomotion allows the robot to travel long distances efficiently by hopping, while preserving its accuracy for short traverses by slow roving. Past robotic missions on asteroids such as Hayabusa 2 deployed surface hoppers to minimize energy consumption in microgravity, but this approach offers limited precision for targeted discovery. ASTRID addresses this limitation by adding wheeled locomotion for short distance traversals, while also making use of its tether to be reeled back by the lander in ball configuration. This report presents ASTRID's design and system architecture, and analytically demonstrates the feasibility of both its hopping and roving modes. We focus on the development of the morphing, hopping and roving mechanisms, and evaluate the robot's capabilities in a scaled microgravity environment. Finally, we discuss the robot's performance results to demonstrate ASTRID's viability for future asteroid exploration.