Mars Exploration Rovers Update - March 2, 2004

SPIRIT UPDATE: Grinding, Take Two - sol 58, Mar 02, 2004 On sol 58, which ends at 7:52 p.m., PST on March 2, the planned four-hour rock abrasion tool grind of "Humphrey" was limited to only 20 minutes. The intricate slopes and cracks of the rock make it a challenging target for instruments. When sensors indicated a loss of contact with surface material, the software perceived a problem and the rock abrasion tool was moved away from the rock. Engineers are amending the software limits to duplicate the rock abrasion tool's earlier operation on the rock "Adirondack," giving a higher likelihood of successful completion on the next sol. The morning began with the completion of the alpha particle X-ray spectrometer integration on the previously brushed area. The panoramic camera then took a multi-spectral observation of the nearby ground, followed by a Mössbauer spectrometer integration on the same area. Spirit's Sol 58 wake-up song was "I Still Haven't Found What I'm Looking For" by U2 to pay homage to its twin rover's amazing findings of water evidence at Meridiani Planum. On sol 59, Spirit will attempt another rock abrasion tool grind on "Humphrey," followed by detailed observations of the hole. OPPORTUNITY UPDATE: Let's Go to 'Last Chance' - sol 37, Mar 02, 2004 On sol 37, Opportunity woke up at 9:35 Local Solar Time to "Let's Go" by the Cars. Opportunity completed the miniature thermal emission spectrometer and panoramic camera surveys of the rock abrasion tool holes at "Guadalupe" and "McKittrick," then drove 4.25 meters (14 feet) to "Last Chance," ending the sol at 7:33 a.m. PST on Tuesday, March 2. With the moves of a tango dancer, the drive was another intricate study in, and challenge of, driving on a slippery, steep slope. The rover was directed to: turn right, go forward, turn right, take images of "Last Chance," turn right, go forward, turn left, go forward, turn right, take images of "Big Bend," go straight, turn left and go straight! Due to the challenges of driving and pirouetting on such a steep slope (as steep as

22 degrees) the rover found it difficult to maintain a perfectly straight course, and Opportunity came up shy and right of the "Last Chance" target by about 30 centimeters (about one foot). The plan for sol 38, which will end at 8:13 a.m. PST on Wednesday, March 3 is to do a short drive again to get within arm's reach of "Last Chance." Once in place, Opportunity will use the science instruments on the end of the robotic arm to analyze "Last Chance."