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.

To see updates on the efforts to free the Spirit rover, visit the JPL Free Spirit website.