Keeping the MSL rover safe against slip and settling while sampling

Extra-terrestrial rover design and operation is a relatively young field. One important aspect of the design and operation of these rovers is to safeguard the vehicle against the loads resulting from the rover slipping or settling, particularly when the robotic arm has placed a science or engineering tool on or near the ground surface. This is a significant engineering challenge because of the need to balance rover slip capability in uncertain terrains with mission mass and volume constraints - and it is a challenge few teams have had to encounter. This paper describes how system requirements, innovative numerical simulations, and an operational process - termed the Slip Risk Assessment Process - are being used on the Mars Science Laboratory Rover. The paper also describes the experience the team has gained from applying these techniques for nearly 400 sols of surface operations, and points to improvements which could benefit future missions.