Daily Updates - May 10, 2004
Opportunity Status at end of sol 101-102

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.

Opportunity Daily Update Archive