"Because the rover will rely on instructions beamed over from Earth via the landing craft, its speed will be less than two feet (0.6 meters) per minute. For the first week, it will only travel about 30 feet (10 meters) from the lander. But what Sojourner lacks in speed, it makes up for in agility. Though it has only five inches of ground clearance, the rover is designed to climb up and over the obstacles it is likely to encounter in the rocky Martian valley where Pathfinder will land. Equipped with six wheels that can move independently, Sojourner can crawl straight up somebody's leg. It can lean up to 60 degrees to either side without tipping over. Its wheels will be able to dig down into the surface of the planet to gather information about the Martian soil."
Taz