We are currently engaged in a study for the ExoMars mission, the first Aurora flagship. We are currently assessing 4-5 different mobility systems that may be deployed on the ExoMars rover. It is known that the mobility system for unmanned robotic planetary exploration vehicles is the backbone of robotic planetary exploration. The past two Mars rover missions - Mars Pathfinder (1997) and MER (2003-4) - the rovers have been required to negotiate notoriously difficult terrain. Each of these vehicles belonging to different weight categories have been limited to a range much below their predetermined daily travel due to the inefficiency of the mobility system to successfully negotiate the terrain. The study here assesses the suitability of various mobility systems, wheeled as well as tracked, that can be deployed on either class of rovers, micro-rovers or mini-rovers. The wheeled concepts under investigation are the RCL concept C, D and E, developed for ESA by the RCL (Russia) along with the US rocker-bogie suspension. The suitability of tracked vehicles for these missions seem much more viable and stable option due to their increased terrain negotiation capability, especially on rough and soft terrain. One of the concepts discussed is called Elastic Loop Mobility System (ELMS) which comprises of a continuous, elastic band as the track element and has power consumption only slightly higher than wheeled vehicles of similar size and mass. We suggest ELMS remains a strong contender for future Mars and Moon missions. Rover mobility performance evaluation tool (RMPET) has been developed during the study to evaluate the performance of wheeled, tracked and legged rovers using Bekker theory. The software provides an option for assessing the performance of vehicles on a variety of soil conditions, for example - Mars soil simulant, lunar soil simulant, a number of terrestrial soils with an option for the user defined soil.

International Astronautical Federation - 55th International Astronautical Congress 2004
Department of Mechanical and Aerospace Engineering

Patel, N. (N.), Ellery, A, & Curley, A. (A.). (2004). Comparative locomotion study for Mars micro-rovers and mini-rovers. In International Astronautical Federation - 55th International Astronautical Congress 2004 (pp. 6257–6267).