Attempt to free Mars rover Spirit, ends with a stall.

In the first step of a 2-step maneuver, Mars Exploration Rover Spirit's right rear wheel stalled once more as it attempted to become free on November 28th, 2009. This isn’t the first time that the wheel stalled, however it did stall more quickly. The stall also didn’t seem to be a factor of the terrain the wheel is in, but rotor resistance within the wheel’s internal actuator.



This blink comparison aids evaluation of a drive by NASA's Mars Exploration Rover Spirit during the rover's 2,099th Martian day, or sol (Nov. 28, 2009).


Project Engineers will now be running diagnostics to check the health of the actuator and any potential terrain hazards before making another attempt to get the rover free. This was part of a series of attempts to free Spirit which began back on November 17th.


Spirit has been stuck in loose soil in an area known as Troy since May. The rover’s wheels are in loose soil with iron sulfate hidden underneath. The composition of the iron sulfate is not the greatest terrain for the rover to travel on as the wheels have much difficulty finding traction.



A screen shot from software used by the Mars Exploration Rover team for assessing movements by Spirit and Opportunity illustrates the degree to which Spirit's wheels have become embedded in soft material at the location called "Troy."


JPL has been using several test rovers, recreating Spirit’s predicament back here on Earth. This alone is a task in itself as compensating for the lower gravity of Mars and atmospheric pressure must be done as well.




Planning an escape for the Mars Exploration Rover, Spirit