NASA Mars Rover Opportunity: Rock Abrasion Tool Shows Anomalous Behavior
sol 1336-1342, Nov 12, 2007:
During the past week, Opportunity continued to investigate the rock layer known as “Smith,” the second of three “bathtub-ring” layers of rock inside “Victoria Crater.” The vehicle is mostly healthy, except for a recent anomaly involving the rock abrasion tool.
Planned operations with the rock abrasion tool failed on Martian day, or sol, 1334 (Oct. 25, 2007), during both the calibration and grind-scan (the procedure for placing the instrument on the target). Data from the vehicle indicated unusual behavior in the encoder of the revolve motor.
On sols 1336 (Oct. 27, 2007) and 1339 (Oct. 30, 2007), the rover conducted diagnostic tests of the rock abrasion tool. Data from the actuator that makes the rock abrasion tool revolve indicated that the encoder was functioning as expected. However, the encoder for the actuator that causes the rock abrasion tool to grind has not been functioning since it failed on sol 1045 (Jan. 1, 2007). Based on the test results, the team decided to go ahead and retry the grind-scan procedure on sol 1341 (Nov. 1, 2007).
Sol-by-sol summary:
In addition to standard observations that included measurements of atmospheric dust with the panoramic and navigation cameras, surveys of the horizon with the panoramic camera, and transfers of data to Earth via the Odyssey orbiter, Opportunity completed the following activities:
Sol 1336 (Oct. 27, 2007): Opportunity conducted diagnostic tests of the rock abrasion tool, placed the Moessbauer spectrometer on Smith, and acquired full-color images of a rock target known as “Walther” using all 13 filters of the panoramic camera. The rover acquired panoramic camera images of the band of rock known as “Lyell” and acquired data from Smith using the Moessbauer spectrometer. The next morning, the rover took a mosaic of images of the lower part of Lyell.
Sol 1337: Opportunity re-started the Moessbauer spectrometer for continued analysis of Smith, completed a survey of the sky at high sun with the panoramic camera, and acquired images of a rock target known as “Ronov” with the panoramic camera. The next morning, Opportunity surveyed and took thumbnail images of the sky with the panoramic camera.
Sol 1338: Opportunity conducted diagnostic tests of the rock abrasion tool and looked for iron-bearing minerals with the Moessbauer spectrometer. The rover acquired panoramic camera images of targets called Lyell, “Lyell NorthPart2,” and “Lyell SouthPart2,” as well as full-color images of a rock target known as “Sorby” with all 13 filters of the panoramic camera. The following morning, Opportunity surveyed and took spot images of the sky with the panoramic camera.
Sol 1339: Opportunity ran more diagnostic tests of the rock abrasion tool and resumed analysis of iron-bearing minerals in Smith with the Moessbauer spectrometer. Opportunity acquired additional panoramic camera images of Lyell. After communicating with the Odyssey orbiter during its overhead pass, Opportunity surveyed the sky at low sun with the panoramic camera.
Sol 1340: Opportunity re-started the Moessbauer spectrometer for continued studies of Smith and acquired additional image mosaics of Lyell using the panoramic camera.
Sol 1341: Plans called for Opportunity to again follow the grind-scan procedure for placing the rock abrasion tool on the target. The rover was to acquire full-color images of a rock target known as “Oppel” and watch the sky for clouds. After communicating with Odyssey, the rover was to turn the alpha-particle X-ray spectrometer skyward and measure atmospheric argon and watch for clouds in the sky.
Sol 1342 (Nov. 2, 2007): Plans called for Opportunity to acquire panoramic camera images of “Cape Verde,” on the rim of Victoria Crater. Opportunity was then to go into a deep sleep and not conduct any science activities on the morning of sol 1343 (Nov. 3, 2007).
Odometry:
As of sol 1340 (Oct. 31, 2007), Opportunity’s total odometry was 11,584.32 meters (7.2 miles).
