On sol 121, after a brief nap, Spirit conducted atmospheric measurements before continuing its trek toward the "Columbia Hills." A 96.8 meter (318 feet) drive that consisted of about half direct drive and half auto-navigational drive broke Spirit's last one-sol distance traveled. That drive brought the mission total to 1,669 meters (1.04 miles), flipping the rover's odometer over the one-mile mark.
Sol 122 was a touch-and-go day, starting with a half-hour alpha particle X-ray spectrometer integration, a one-hour Mössbauer integration and a set of four microscopic images all on the same patch of soil. Panoramic camera and miniature thermal emission spectrometer data were also obtained before an afternoon nap. The bulk of the afternoon was spent driving another 65 meters (213 feet).
Sol 123 started off with Panoramic camera and miniature thermal emission spectrometer observations for near-field surveys, atmospheric studies, and localization. Spirit then took a half-hour nap, followed by the day's drive. This sol consisted of another 48-meter (about 157-feet) direct drive, the mid-drive survey and localization remote sensing, and then 47-meters (about
154 feet) of driving using auto-navigation. The total was 95.2 meters (312 feet), bringing the mission total to 1830 meters (1.14 miles).OPPORTUNITY UPDATE: 'Deep Sleep' Gives Opportunity More Energy to Cruise the Crater - sol 101-102, May 10, 2004
Opportunity awoke on sol 102 from its first "deep sleep." This set of activities was initiated to conserve the energy that is being used by the instrument arm's stuck-on heater switch. During deep sleep, rover planners power off the main electronics at night and open the switches that supply battery power to the main power bus, and in turn nearly all the secondary electronics. In particular this removes power input to the Rover Power Distribution Unit, which normally supplies power to the stuck-on heater. With the Rover Power Distribution Unit input turned off, the heater cannot burn any energy either. In the morning, when the sun strikes the solar panel array, the Battery Control Board resets and connects the batteries to the main power bus again. At this time, the stuck-on heater again draws power, but this will only be for a few hours in the morning instead of all night.
The most vulnerable instrument to the cold martian nights is the miniature thermal emission spectrometer. With a cutoff of the power electronics, its heater cannot keep it warm overnight. Data returned on sol 102 showed the temperature reached -46 degrees Celsius (-50.8 degrees Fahrenheit), a bit warmer than the spectrometer's lowest proven temperature for functionality, -50 degrees Celsius (-58 degrees Fahrenheit).
Rover planners commanded Opportunity to take a drive during the afternoon of sol 102 to the south, along the edge of the crater toward a dark rock in the vicinity.
More remote sensing was conducted, including miniature thermal emission spectrometer measurements that confirmed the instrument is still functioning normally after deep sleep.
Wake-up songs for the sols were "Morning has Broken" by Cat Stevens; "Hallelujah Chorus" from George Frideric Handel's Messiah; and "Dazed and Confused" by Led Zeppelin.