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Rocky 7 - Mojave Desert Field ExperimentsExperimenter's Notebook
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The main goal for Wednesday's field test was to complete a 200 m traverse. This long traverse was broken up into 10 smaller traverses from 10 m to 30 m long. At the start of each traverse a panoramic image was taken by the rover, and this image was used by the Engineering Team to select waypoints for the rover's route in the traverse. The Science Team also selected various interesting targets for the rover to approach. Several of these science targets the rover simply drove near and imaged with its stereo mast cameras. Due to time constraints, only one rock sample was able to be examined closely with Rocky 7's close-up imager.
Rocky 7's traverse started near Spa Crater's outwash system, a dendritic drainage system leading from the crater and spreading out over the playa. Moving parallel to this drainage system, Rocky 7 then skirted the rim of Spa Crater, travelling over the crater's ejecta blanket. After the rover safely cleared this crater, the controllers commanded it to approach a rock target designated by the Science Team. A close-up image of this rock sample was needed in order to test Rocky 7's close-up imager on a valid target. This particular rock sample was partially covered with caliche deposits. This white crust is simply calcium carbonate which seeps out of the ground and coats the rock. This is caused by the presence of groundwater. Therefore, if caliche deposits are seen on Mars rocks, they will be indicative that water was once more common on Mars. This test would determine if Rocky 7's close-up imager could see these caliche deposits on a rock. Once Rocky 7 positioned itself near the rock sample, the rover deployed its stereo mast cameras in order to obtain an overhead image of the rock from a range of approximately 1 m. This overhead image was used by the Science Team to select the area the close-up imager would photograph. Rocky 7 positioned its mast against the rock and a color image of the surface of the rock was obtained.
After finishing this imaging test, Rocky 7 continued navigating through the rock field, coming within a few meters of another large crater, Tadpole. The rover continued its 250 m traverse, taking panoramic images as necessary for science and navigation purposes. Near the end of the 250 meters, Rocky 7 began encountering the Pisgah Volcano lava flows. The rover maneuvered over rough basalt cobbles with ease, and at the end of the traverse began climbing atop the 0.5 m tall lava flow at an incline of 10 degrees with apparent ease. However, with the sun setting behind the mountains, Rocky 7 quickly lost its navigation fix with its sun sensor, and Wednesday's testing had to be called to a halt.