Although the scientific return on the MERs has been spectacular, there is a fundamental restriction with planetary robotic missions to-date: the locomotion system. The MERs are very advanced wheeled robots, capable of climbing reasonable-sized rocks and avoiding larger ones. However, they were designed to traverse regions only covered by these smaller rocks and sparsely covered by larger rocks. Traversing regions with more, larger rocks would be difficult for these vehicles, if not impossible. Fortunately, a solution exists for the locomotion systems to negotiate these more hostile terrains: Legs. This paper will show how legged locomotion is more expedient than wheeled locomotion for planetary exploration. This is shown through the measurement of the forward tractive effort of the vehicle (drawbar pull) and the comparison of this metric to wheeled missions.

Space 2005
Department of Mechanical and Aerospace Engineering

Scott, G.P. (Gregory P.), & Ellery, A. (2005). Using Bekker theory as the primary performance metric for measuring the benefits of legged locomotion over traditional wheeled vehicles for planetary robotic explorers. In Collection of Technical Papers - AIAA Space 2005 Conference and Exposition.