Martian Dust Begins to Settle
Aug. 09, 2007 / sol 1268-1273
SPIRIT UPDATE: Martian Dust Begins to Settle -- Right on Top of the Solar Arrays
Spirit is healthy and continues to ride out the dust storms on Mars. In fact, atmospheric dreariness has improved in the last few Martian days, or sols, but as dust settles out of the atmosphere, it settles onto the solar arrays, keeping power levels relatively low.
Measurements of the amount of sunlight blocked from reaching the rover, known as Tau, dropped from a record high of 4.738 on sol 1265 (July 25, 2007) to 3.813 on sol 1273 (Aug. 2, 2007). Solar power levels leveled off at around 260 to 300 watt-hours per sol (100 watt-hours is the amount of energy needed to light a 100-watt bulb for one hour).
Weather reports from the Mars Color Imager on the Mars Reconnaissance Orbiter indicate the storms may be in the early stages of decay. Spirit continues to use power conservatively in view of the recent jump in dust levels and the struggle for survival by Spirit's twin, the Opportunity rover, on the opposite side of the red planet.
Spirit remains parked just east of the elevated plateau known as "Home Plate," with the Mössbauer spectrometer placed on the target known as "Innocent Bystander." On sol 1273 (Aug. 2, 2007), Spirit performed a 5-hour study with the Mössbauer spectrometer.
After the dust settles, Spirit's handlers on Earth plan to have the rover continue collecting Mössbauer data from Innocent Bystander for a few sols, acquire microscopic images of the new dust layer on the soil, and drive onto Home Plate.
Except where noted, daily communications activities included morning, direct-from-Earth uplinks over the rover's high-gain antenna and evening relays of data to Earth at UHF frequences via the Odyssey orbiter. In addition, Spirit completed the following activities:
Sol 1268: Spirit measured atmospheric Tau with both the panoramic camera and navigation camera. The rover did not relay data to Earth to conserve power.
Sol 1269: Spirit measured Tau and completed a sky survey using the panoramic camera. The rover's handlers on Earth did not send instructions to the rover to conserve power.
Sol 1270: Spirit measured Tau and completed a sky survey using the panoramic camera. The rover's handlers on Earth did not send instructions to the rover to conserve power.
Sol 1271: Spirit measured Tau and completed a sky survey using the panoramic camera. The rover measured Tau using the navigation camera and acquired images of sand ripples on the surface with the front hazard avoidance camera.
Sol 1272: Spirit took more images of sand ripples with the front hazard avoidance camera as well as with the rear hazard avoidance camera. The rover acquired a mosaic of sand ripple images with the navigation camera. Spirit measured atmospheric dust, acquired images of the sky, completed a horizon survey, and acquired images of the "El Dorado" dune field with the panoramic camera. To conserve power, Spirit did not send data to Earth.
Sol 1273 (Aug. 2, 2007): Spirit studied Innocent Bystander with the Mössbauer spectrometer.
As of sol 1265 (July 25, 2007), Spirit's total odometry remained at 7,153 meters (4.44 miles).