Opportunity Peers Beneath Surface of "Bathtub Ring"
Nov. 20, 2007

Title	:	Opportunity Peers Beneath Surface of "Bathtub Ring" Nov. 20, 2007
Description	:	Opportunity remains parked at the rock layer known as "Smith" -- part of the "bathtub ring" of rock layers beneath the edge of "Victoria Crater -- at "Duck Bay," the alcove where the rover entered the crater. During a test of the wire brush on the rock abrasion tool in a new mode of operation developed to work around recent encoder failures, Opportunity was mistakenly commanded to rotate the brush in the wrong direction. As a result, the brush appears to have been bent outward, perpendicular to the plane of rotation. The engineering team is currently testing strategies for mitigating the bent brush. The science team's top priority is to grind deeper into Smith and collect compositional data about the rock using the alpha-particle X-ray spectrometer. Opportunity is otherwise healthy, with solar array energy levels around 660 watt-hours and atmospheric dust measurements, known as Tau, at 0.9 (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour). Sol-by-sol summary: In addition to morning uplinks directly from Earth via the rover's high-gain antenna, evening downlinks to Earth via the Odyssey orbiter at UHF frequencies, and standard panoramic-camera measurements of atmospheric opacity caused by dust, Opportunity completed the following activities: Sol 1349 (Nov. 9, 2007): Opportunity acquired a mosaic of images of "Cape Verde" from below and a mosaic of images of Smith using the panoramic camera. The rover relayed data to Odyssey during an overnight pass of the orbiter. Sol 1350: Opportunity completed diagnostic tests of the rock abrasion tool, measured argon in the Martian atmosphere using the alpha-particle X-ray spectrometer, and acquired full-color images, using all 13 filters of the panoramic camera, of the freshly brushed surface of Smith. Sol 1351: Opportunity acquired an image mosaic of Smith with the panoramic camera and relayed data to the Odyssey orbiter overnight. Sol 1352: Opportunity took images of "Cabo Frio" with the panoramic camera and ran diagnostic tests of the rock abrasion tool. The rover acquired images of the rock abrasion tool with the panoramic camera and placed the Mössbauer spectrometer on Smith in preparation for measuring the abundance and composition of iron-bearing minerals. Opportunity then acquired data using the Mössbauer spectrometer. The rover took additional images of Cabo Frio and Cape Verde -- both promontories of the scalloped rim of Victoria Crater -- with the panoramic camera. Opportunity also acquired a mosaic of images of the rock layer known as "Lyell" using the panoramic camera. Sol 1353: Opportunity continued to collect data from Smith with the Mössbauer spectrometer. Opportunity took panoramic-camera images of Cape Verde and Cabo Frio at different times of day and took spot images of the sky. Sol 1354 (Nov. 15, 2007): Opportunity completed diagnostic tests of the rock abrasion tool with the panoramic camera and placed the alpha-particle X-ray spectrometer on the external capture magnet. The rover tested UHF communications with the Mars Reconnaissance Orbiter in preparation for next year's arrival of the Phoenix lander. Opportunity took panoramic-camera images of Cape Verde, acquired compositional data about dust particles on the capture magnet using the alpha-particle X-ray spectrometer, and took thumbnail images of the sky with the panoramic camera. Odometry: As of sol 1354 (Nov. 15, 2007), Opportunity's total odometry remained at 11,584.32 meters (7.2 miles).
Credit	:	NASA / JPL