This thesis investigates low degree-of-freedom (DoF) rover mobility architectures for planetary exploration. These platforms seek to reduce mass and complexity compared to the heritage rocker-bogie system while maintaining functional performance. The work focuses on two platforms: MoonRanger, a lightweight lunar micro-rover slated for a 2029 mission, and Zoë2, a research rover developed as a successor to CMU’s 22-year old Zoë rover.

For MoonRanger, we analyze the limitations of the gravity offload method for Earth-based mobility testing and validate alternative approaches using granular scaling laws, single-wheel experiments, and high-fidelity discrete element modeling (DEM). Results demonstrate that offload testing significantly overestimated performance, while full-mass testing and DEM provide more accurate predictions of lunar behavior. A wheel design study using fractional factorial design (FFD) and black-box optimization are initiated to identify promising configurations for future missions.

The second part of this thesis details the design, implementation, and evaluation of Zoë2, a passive-steering rover optimized for energy efficiency and maneuverability. We find that compared to skid steering, passive steering reduces power consumption during turning by up to 30% while simultaneously allowing far more precise blind navigation. Experimental validation confirms that the redesigned mechanical, electrical, and software systems provide a versatile testbed for planetary autonomy research.

Together, these studies highlight the tradeoffs between simplicity, efficiency, and mobility performance in planetary rover design. The findings contribute to the development of lighter, more capable mobility systems for future lunar and planetary missions.

Corresponding talk available at https://www.youtube.com/watch?v=cFUolfZ_kgg.