Spirit took it easy the morning of sol 112, which ended at
8:30 a. m. PDT on April 27, and didn't begin operations until 11:45 a.m. Mars Local Solar time, to conserve energy for an afternoon drive. Before taking off, Spirit gathered some soil and atmospheric observations with the mini thermal emission spectrometer and panoramic camera.Then the drive began. Spirit's updated autonomous navigation software proved its worth again this sol. During a long auto-navigation segment, the rover encountered a hazard and was able to back up and find a way around it. Spirit continued to drive backwards towards its intended goal point, using the rear hazard avoidance cameras to navigate the way. When the allotted drive time was up, Spirit turned back around and made one last short drive to its resting place for the night. Spirit's odometer records backwards and forwards driving and logged another 88.6 meters (290.7 feet) for the sol 112 drive. The actual distance covered was about 60 meters (197 feet).
On Sol 113, which ended at 9:09 a.m. PDT on April 28, Spirit woke up earlier than normal, 9:00 a.m. Mars Local Solar time, to do morning atmospheric science. One objective of the early sky scan was to image morning clouds with the panoramic camera. Spirit then began an intense study of a soil spot called "MayFly." During her examination of the area, Spirit took panoramic camera and mini thermal emission spectrometer images in parallel, conducted a two-hour Mössbauer integration and finished off with a look through the microscopic imager. The rover then stowed the instrument arm to prepare for digging a trench.
Rover planners intended for Spirit to use its wheels to dig a trench at the MayFly spot, but hazard avoidance camera images of the area showed a potato-size rock that could have potentially fallen into the wheel hollow in the process. Rather than take that risk, controllers decided to back the rover up 10 centimeters (3.9 inches) to a clearer spot. After the final positioning, Spirit used its wheels to dig a 6-centimeter (2.4-inch) trench. Spirit finished the sol with hazard avoidance camera images of the trench, which was used to plan Mössbauer, alpha particle X-ray spectrometer and microscopic imager work on sol 114.
On sol 114, which ended at 9:49 a.m. PDT on April 29,
2004 Spirit continued to investigate the trenched area with the Mössbauer spectrometer, alpha particle X-ray spectrometer and the microscopic imager.OPPORTUNITY UPDATE: Opportunity Edges Its Way Toward 'Endurance' - sol 92-93, Apr 29, 2004
Opportunity spent sols 92 and 93, which ended at 8:51 p.m. PDT on April 27 and 9:30 p.m. PDT on April 28 respectively, edging its way closer to "Endurance Crater." A total drive of 106 meters (347.8 feet) left the rover just 70 meters (229.7 feet) from the rim.
The pattern for these two sols has been to take pre- and post-drive remote sensing observations and imaging in the crater direction between midday energy-conserving naps.
By sol 95, Opportunity will make the final approach to Endurance Crater.