Increased Flexibility and Robustness of Mars Rovers

Our overall objective is to improve the productivity of Mars rovers by increasing the exibility and robustness of their autonomous behavior. To achieve this objective, we set out to increase the on-board autonomy of rovers and enable commanding at a higher level with a more exible command language. In February, 1999, we demonstrated some of our rover autonomy technologies as part of a Marsokhod rover eld test that simulated aspects of the Mars '01{'05 missions. In this paper, we present the commanding language employed in this eld test, called the Contingent Rover Language (CRL), and describe the ground tools and on-board executive capabilities that were developed to generate and execute CRL plans. A key feature of CRL is that it enables the encoding of contingent plans specifying what to do if a failure occurs, as well as what to do if a serendipitous science opportunity arises.