Mars Exploration Rover team members continued longer-duration test runs this week, driving the test rover forward and uphill in a crab-like position. These long-duration drives will continue through the end of next week.

Engineers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., are using a test rover in a box filled with soil to mimic the Martian surface to test a combination of maneuvers that may be used to free the Spirit rover, which is dug in on Mars in soft soil called "Troy." Pictured are Matt Van Kirk with Sharon Laubach.

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