In January, 2004, the Mars Exploration Rover (MER) mission landed two rovers, Spirit and Opportunity, on the surface of Mars. Several autonomous navigation capabilities were employed in space for the first time in this mission. In the Entry, Descent, and Landing (EDL) phase, both landers used a vision system called the Descent Image Motion Estimation System (DIMES) to estimate horizontal velocity during the last 2000 meters (m) of descent, by tracking features on the ground with a downlooking camera, in order to control retro-rocket firing to reduce horizontal velocity before impact. During surface operations, the rovers navigate autonomously using stereo vision for local terrain mapping and a local, reactive planning algorithm called Grid-based Estimation of Surface Traversability Applied to Local Terrain (GESTALT) for obstacle avoidance. In areas of high slip, stereo visionbased visual odometry has been used to estimate rover motion. As of mid-June, Spirit had traversed 3405 m, of wh...
Mark W. Maimone, Andrew Edie Johnson, Yang Cheng,