From Gaits to Support Dynamics: Rethinking Locomotion for Space Robotics

Robotic mobility remains a major challenge in planetary exploration, particularly in environments characterized by uncertain terrain interaction, low gravity, and irregular contact conditions. Conventional wheeled and gait-based locomotion strategies typically rely on predefined contact patterns and motion-centric control formulations, which can become fragile in highly unstructured extraterrestrial environments such as lava tubes, crater walls, and granular slopes. This perspective proposes a support-centric interpretation of locomotion in which mobility is viewed as the continuous generation, redistribution, and adaptation of support under uncertain interaction conditions. Rather than treating contact as a secondary constraint within trajectory execution, the proposed framework interprets locomotion through the evolution of support configurations, support quality, and contact reliability. The paper synthesizes developments in terramechanics, adaptive legged locomotion, bio-inspired robotics, and learning-based control to establish conceptual links between contact interaction and support evolution. A conceptual framework for learning support dynamics is further introduced to outline possible directions for adaptive multi-contact locomotion in space robotics. The proposed perspective is intended not as a replacement for existing locomotion methods, but as a higher-level framework for guiding future research in robust terrain-adaptive robotic mobility.