- Press Release
- Oct 2, 2022
NASA Mars Rover Status Report 30 Jun 2004
SPIRIT UPDATE: Just a Little Rock Abrasion Tool – sol 167-170, June 30, 2004
On sol 167, Spirit looked at a bit of soil called "Jaws" with
the alpha particle X-ray spectrometer and microscopic imager.
Then the rover completed a drive intended to put it into
position to analyze "Pot-of-Gold" with the instruments on
its robotic arm. The drive moved Spirit farther than expected
though, and the rover ended up directly over the rock. That
position prevented any observations with the instrument
On sol 168, rover planners commanded Spirit to "bump" backward,
into a position where the rock abrasion tool could make contact
with Pot-of-Gold. This was successful, and Spirit spent the
rest of the time taking images of the surrounding area with
its panoramic and navigation cameras.
On sol 169, Spirit successfully operated its rock abrasion
tool on Pot-of-Gold, grinding away the top .2 millimeters
(.008 inches) of rock from the high points. The procedure
took 1 hour and 45 minutes. Pot-of-Gold posed a special
challenge to the rover team because it is quite small — only
slightly larger than the rock abrasion tool instrument itself.
The rock abrasion tool inflicts about 6.8 kilograms (15 pounds)
of pressure on its rock targets, and smaller rocks aren’t
necessarily stable enough to resist this.
Before and after pictures of Pot-of-Gold showed that the rock
was moved by the rock abrasion tool procedure. That movement,
plus possible slippage where the tool contacts the rock,
resulted in only intermittent contact during the grinding
operation. After the grind was complete, Spirit placed the
alpha particle X-ray spectrometer on the freshly exposed area
in preparation for an operation later that night.
On Sol 170, Spirit awoke to stop the alpha particle X-ray
integration, took miniature thermal emission spectrometer and
panoramic camera images of some local track marks, took more
microscopic images of the newly exposed Pot-of-Gold, then
placed the Mo"ssbauer instrument on the site for a 21-hour