Spirit used its rock abrasion tool for brushing the dust off three patches of a rock called "Humphrey," during its 55th sol on Mars, ending at 5:53 p.m. Saturday, PST. Before applying the wire-bristled brush, the rover inspected the surface of the rock with its microscope and with its alpha particle X-ray spectrometer, which identifies elements that are present. Brushing three different places on a rock one right after another was an unprecedented use of the rock abrasion tool, designed to provide a larger cleaned area for examining.
Afterwards, Spirit rolled backward 85 centimeters (2.8 feet) to a position from which it could use its miniature thermal emission spectrometer on the cleaned areas for assessing what minerals are present. Due to caution about potential hazards while re-approaching "Humphrey," the rover moved only part of the way back. Plans for sol 56, ending at 6:33 p.m. Sunday, PST, call for finishing that re-approach and further inspecting the brushed areas. If all goes well, the rock abrasion tool's diamond-toothed grinding wheel will cut into the rock on sol 57 to expose fresh interior material.
For wake-up music on sol 55, controllers chose "Brush Your Teeth," by Cathy Fink and Marcy Marxer, and "Knock Three Times," by Tony Orlando and Dawn.
OPPORTUNITY UPDATE: "Guadalupe" Under the Microscope - sol 35, Feb 29, 2004
During its 35th sol on Mars, ending at 6:14 a.m. Sunday, PST, Opportunity manipulated the microscopic imager at the tip of its arm for eight observations of the fine textures of an outcrop-rock target called "Guadalupe." The observations include frames to be used for developing stereo and color views.
Opportunity also used its Moessbauer spectrometer and, after an overnight switch, its alpha particle X-ray spectrometer to assess the composition of the interior material of "Guadalupe" exposed yestersol by a grinding session with the rock abrasion tool.
The panoramic camera up on the rover's mast captured a new view toward the eastern horizon beyond the crater where Opportunity is working, for use in evaluating potential drive directions after the rover leaves the crater.
Jimmy Cliff's "I Can See Clearly Now," was played in the mission support area at JPL as Opportunity's sol 35 wake-up music.
Plans for sol 36, ending at 6:54 a.m. Monday, PST, called for finishing the close-up inspection of "Guadalupe," then backing up enough to give the panoramic camera and miniature emission spectrometer good views of the area where the rock interior has been exposed by grinding.