NASA's Spirit has begun pivoting atop its lander platform on Mars, and the robot's human partners have announced plans to send it toward a crater, then toward some hills, during the mission. Determining exactly where the spacecraft landed, in the context of images taken from orbit, has given planners a useful map of the vicinity. After Spirit drives off its lander and examines nearby soil and rocks, the scientists and engineers managing it from NASA's Jet Propulsion Laboratory, Pasadena, Calif., intend to tell it to head for a crater that is about 250 meters (about 270 yards) northeast of the...