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Rocky 7 - Mojave Desert Field ExperimentsExperimenter's Notebook
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After reviewing the first two days of the test, it was decided that more experiments on the Sunshine Flow were needed. To make room for these added experiments, the planned rover activities around waypoint B were dropped from the schedule. Instead of the long traverse across the playa from waypoint A to waypoint B, an extra traverse from Sunshine Flow down onto the playa, a traverse searching for caliche within the aeolian accretion mantle on the flow, and an extended playa traverse were added. This group of traverses are referred to as the Sunshine Flow Margin and Caliche Search traverses. The schedule change provided an opportunity for further science experiments dealing with recognizing interesting science targets in a complex terrain. These benefits were judged to outweigh the benefits of a long distance traverse over the flat, obstacle-free playa.
Rocky 7 was placed 25 meters west of the end point of the Sunshine Flow traverse, about 15 meters into the flow. After taking a stereo panoramic image, the operators commanded the rover to approach a patch of exposed soil on the flow. The rover covered the 5 meters to the patch of soil. A typical science sequence was started, consisting of an overhead stereo image, a soil sample obtained with the manipulator arm, a PR measurement, and another overhead stereo image so that any changes the manipulator arm sample scoop had on the surface could be seen. After completing this science sequence, Rocky 7 traveled the remaining 10 meters to the playa. At this point it was decided to continue this Sunshine Flow Margin traverse later, and Rocky 7 was picked up and moved to waypoint C so that the Playa Crater Field traverse could begin.
The playa surrounding waypoint C is strewn with craters of varying sizes and depths. Since this is a type of terrain expected at many of the probable rover landing sites on Mars, extensive rover traversing and science experiments were scheduled to be conducted in the area. Rocky 7 was placed at waypoint C and a color stereo panoramic image was acquired. The stereo mast camera filter wheel, however, got stuck, forcing a few hours of down time as the engineering team worked to solve the problem. Eventually, a tiny piece of basalt was discovered in the stereo camera housing jamming the filter wheel. After it was removed Rocky 7 was again placed at waypoint C and another color stereo panoramic image was taken. The operators sent commands for a short move to obtain a better viewing position and once there took another stereo panormaic image. In this image the operators identified their science target: a shallow crater about 15 meters to the west. The rover neared the crater, pausing at its rim to acquire a stereo panoramic image, as well as an overhead stereo image of the crater rim and the dendritic drainage "tail." Rocky 7 then moved into the crater to examine it for any signs of water. After taking a navigation image, the controllers in the trailer identified mudcracks covering the floor of the crater, earning this crater its name: Mudcrack Crater. A science sequence similar to the one performed earlier in the day was again performed: an overhead stereo image was taken, a soil sample acquired, a PR measurement taken, and another overhead stereo image was finally taken. After this science sequence was over testing was concluded for the day.