Spirit Mars Rover: Unexpected Wheel-Test Results

December 15, 2009
Diagnostic tests were run on Spirit's right-rear wheel and right-front wheel on Sol 2013 (Dec. 12, 2009). Image Credit: NASA/JPL-Caltech (Click Enlarge for animation)

(PhysOrg.com) -- Diagnostic tests were run on Spirit's right-rear wheel and right-front wheel on Sol 2013 (Dec. 12, 2009).

The right-rear wheel, which stalled during a drive two weeks earlier, continued to show no motion in the latest tests and exhibited very high resistance in the motor winding. The right-front wheel, which stopped operating on Sol 779 (March 13, 2006), surprised engineers by indicating normal resistance and turning slightly during a resistance test for that wheel.

Small motion is expected during an electrical resistance test for an operating actuator, but the right-front actuator was expected to be non-operational. The right-front wheel was last checked just after its apparent failure in 2006 and at that time indicated an open circuit. Although no clear theory for failure had been established, the was generally regarded as permanent. It is important to remember that the Sol 2013 test of the right-front was only a rotor resistance test, and no conclusions can be drawn at this point without further testing.

The plan for Spirit on 2116 (Dec. 15) is to command a drive. This drive will further investigate functionality of the right-front and right-rear wheels. The results are expected Wednesday.

Explore further: Spirit Completes Fourth Mile On Mars

Related Stories

Spirit Completes Fourth Mile On Mars

February 14, 2006

Spirit is healthy and continues to make progress toward "Home Plate" after driving more than 150 meters (492 feet), taking images, making atmospheric observations, and analyzing geology.

Free Spirit: Third Extrication Drive Ends With Wheel Stall

November 23, 2009

(PhysOrg.com) -- Spirit experienced a wheel stall with the right-rear wheel during the second step of a two-step drive on Sol 2092 (Saturday, Nov. 21). This is not the same wheel that stalled on Sol 1899 (May 6), the left-middle ...

Further Tests Designed for Rover's Right-Rear Wheel

December 8, 2009

(PhysOrg.com) -- A series of diagnostic tests on Spirit's right-rear wheel on sols 2104 and 2105 (Dec. 3 and 4) investigated stalls that occurred on Sol 2099 (Nov. 28) and earlier. The rover team cannot draw any conclusions ...

Spirit Rover: Rear Wheel Trouble Continues

December 10, 2009

(PhysOrg.com) -- Results of diagnostic tests on Spirit's right-rear wheel on Sol 2109 (Dec. 8, 2009) continue to indicate a troubled wheel, which may leave the rover with only four operable wheels.

Recommended for you

What are white holes?

October 9, 2015

Black holes are created when stars die catastrophically in a supernova. So what in the universe is a white hole?

How to prepare for Mars? NASA consults Navy sub force

October 5, 2015

As NASA contemplates a manned voyage to Mars and the effects missions deeper into space could have on astronauts, it's tapping research from another outfit with experience sending people to the deep: the U.S. Navy submarine ...

A mission to a metal world—The Psyche mission

October 9, 2015

In their drive to set exploration goals for the future, NASA's Discovery Program put out the call for proposals for their thirteenth Discovery mission in February 2014. After reviewing the 27 initial proposals, a panel of ...


Adjust slider to filter visible comments by rank

Display comments: newest first

4 / 5 (1) Dec 16, 2009
A high resistance reading on a motor coil would mean that there was a break in the wire of the coil. However, the two "ends" could still be close enough to each other that there would be intermittent conduction upon expansion or contraction of the coil due to temperature changes, or if there were enough motion to jostle them together. Either way, it would only be for brief amounts of time. They should definitely NOT get their hopes up on this one!
Dec 16, 2009
This comment has been removed by a moderator.
not rated yet Dec 16, 2009
The whole unit of Spirit had an planned life time of three months. It has worked past that time many times over. Not everything works anymore, but that's to be expected. Maybe in the next iteration they can design a better device taking measures to mitigate the effect of different failures.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.