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Scientists and engineers got a nice bonus in that two spherical features nicknamed "blueberries" were unexpectedly cut in half within this rock. Team members had noticed the blueberries in earlier pictures on other rocks in the outcrop and had wanted to attempt to cut one in half sometime during the future of the mission. As luck would have it, two blueberries were hidden in the depths of "McKittrick." The one blueberry shown in the bottom right of this picture appears to have been scratched by the grinding wheel, which is further explained in image #2. The two rectangular boxes in the lower left and upper middle parts of this image are "drop outs," where the data packets inadvertently did not make it back to Earth during the initial communications relay via the Deep Space Network antennas. The missing data packets should be resent to Earth within the next few days. Just above each of the black "drop out" rectangles is another rectangular area filled with a cluster of smaller rectangles in different shades of gray, which are image compression artifacts. For more information about the "blueberries," please see JPL's Press Release dated February 9, 2004. For more microscopic images of the results from Opportunity's first use of the rock abrasion tool, please see the raw images for sol 30. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y. Image credit: NASA/JPL/Cornell/US Geological Survey
In the original microscopic image underlaying the graphics, engineers and scientists noticed "layers" or "scratches" on the spherical object nicknamed "blueberry" in the lower right part of the image. The designers of the rock abrasion tool noticed that the arc length and width of the scratches were similar to the shape and size of the rock abrasion tool's grinding wheel, which is made out of a pad of diamond teeth. The scrapes on the bottom right blueberry appear to be caused by the fact that the berry got dislodged slightly and its surface was scraped with the grinding pad. In this image, the largest yellow circle is the overall diameter of the hole ground by the rock abrasion tool and the largest yellow rectangular shape is the area of the grinding wheel bit. The smaller yellow semi-circle is the path that the center of the grinding tool follows. The orange arrow arcing around the solid yellow circle (center of grinding tool) indicates the direction that the grinding tool spins around its own center at 3,000 revolutions per minute. The tool simultaneously spins in an orbit around the center of the hole, indicated by the larger orange arrow to the left. The grinding tool is 22 millimeters (0.9 inches) in length and the actual grinding surface, which consists of the diamond pad, is 1.5 millimeters (0.06 inches) in length, indicated by the two smaller rectangles. You can see that the smaller bottom rectangle fits exactly the width of the scrape marks. The grooves on the blueberry are also the same as the curvature of the arced pathway in which the grinding tool spins. By overlaying appropriately scaled representations of the rock abrasion tool schematics, the evidence reveals a strong indication that the scrapes on the blueberry were induced by the tool, rather than caused by some natural geologic process. The two rectangular boxes in the lower left and upper middle parts of this image are "drop outs," where the data packets inadvertently did not make it back to Earth during the initial communications relay via the Deep Space Network antennas. The missing data packets should be resent to Earth within the next few days. Just above each of the black "drop out" rectangles is another rectangular area filled with a cluster of smaller rectangles in different shades of gray, which are image compression artifacts. The rock abrasion tools on both Mars Exploration Rovers were supplied by Honeybee Robotics, New York, N.Y. Image credit: NASA/JPL/Cornell/US Geological Survey Daily Updates - February 25, 2004 Spirit Status for sol 52 On sol 52, which ended at 3:54 p.m. PST, February 25, rover engineers drove Spirit the short 4-meter (13.1 feet) drive to "Middle Ground" after finishing observations with the miniature thermal emission and Moessbauer spectrometers. Several stutter steps that would have put Spirit at the exact target location were not executed because they were programmed with built-in safeties. The rover detected slight hazards and stopped within its constraints. The final steps will be executed next sol. Waking up to Foreigner's "Cold as Ice," Spirit's first job of the sol was to warm up its arm that was significantly colder than yestersol due to the rover's orientation to the northwest. The engineering team also took a moment to wave to Spirit as its panoramic camera faced and imaged Earth. Spirit will remain at "Middle Ground" for the next several sols and continue observing targets with its spectrometers and microscopic imager. Plans also call for high-resolution images of rocks and an examination of the soil. -------------------------------------------------------------------------------- On sol 31, which ended at 3:36 a.m. Wednesday, February 25, Opportunity awoke to "Rock Around the Clock" by Bill Haley and his Comets. At 1:00 a.m. Local Solar Time, Opportunity sent data to Earth via the Mars Global Surveyor orbiter and then sent another whopping 145.6 megabits of data at 3:30 a.m. Local Solar Time via the Mars Odyssey orbiter. During the morning hours, Opportunity collected data with the alpha particle X-ray spectrometer for five hours and took measurements with its miniature thermal emission spectrometer from inside its newly formed hole that was created on sol 30 by the rock abrasion tool. Later, Opportunity retracted and closed the door of the alpha particle X-ray spectrometer and swapped the Moessbauer spectrometer into the hole made by the abrasion tool for a leisurely 24-hour observation. Opportunity also updated its "attitude knowledge," which fine-tunes the rover's information about its exact location and position on Mars. Updating the attitude knowledge allows the rover to more accurately point the high gain antenna toward Earth, which increases the communications capabilities. The attitude adjustment also enables scientists and engineers to point instruments onboard Opportunity more precisely at targets of interest, such as particular rocks and patches of soil. To adjust the attitude knowledge, engineers have the rover turn the panoramic camera to the Sun and watch the Sun travel across the sky for 15 minutes. The rover is then smart enough to take the Sun movement data collected from the panoramic camera to calculate its own location in the universe…..on Mars. The rover gathers attitude knowledge errors over time as it drives and uses the robotic arm extensively, but it only needs an attitude adjustment about once a week or after driving long distances. Around 12:15 pm Local Solar Time, Opportunity went to sleep to recharge its batteries from its strenuous rock abrasion tool activities on sol 30, but reawakened briefly at 4 p.m. Local Solar Time and again in the evening to send data to Earth via additional overflights by the Mars Global Surveyor and Odyssey orbiters. The plan for sol 32, which ends at 4:15 a.m. Thursday, February 26, is to take another unique set of Moessbauer measurements to look at the rover-created hole in a different spectrum. The goal is to then crawl slightly forward on sol 33 to position Opportunity to use the rock abrasion tool on the upper target of the El Capitan/McKittrick area. Mars rover Daily Updates -Spirit Making Ground - Opportunity-A Beautiful Grind ^ Today's Stereogram from Mars - Microscopic image of spherule(Opportunity)-Pancam(Spirit) sol-29 ^ Rover Daily Updates-February 21, 2004-Down in the Trench(Spirit-Supersized Science(opportunity) ^ Opportunity Examines Trench as Spirit Prepares to Dig One February 19, 2004 ^ Daily Updates - February 18, 2004 - Mars rovers, Opportunity, Spirit . . . ^ |
