Mike Seibert and Sharon Laubach, engineers on the Mars Exploration Rover team at NASA's Jet Propulsion Laboratory, Pasadena, check the exact position of a test rover in preparation for the next test of a possible maneuver for Spirit to use on Mars. The test setup at JPL simulates the situation where Spirit is embedded in a patch of soft soil dubbed "Troy," in Mars' Gusev Crater. The July 7, 2009, preparation shown here preceded an assessment of straight-backward driving the next day, one of several possible maneuvers to be assessed in the test sandbox before further driving commands will be sent to Spirit.
