Dust Storm Clears Slightly for Mars Rovers
Spirit moved its robotic arm during the rover's 1,277th Martian day (Aug. 6) for the first time in 20 days. Image
Credit: NASA/JPL-Caltech/Cornell.

Dust in the martian atmosphere has settled slightly, allowing more sunlight to reach the solar panels of NASA's power-starved rovers Spirit and Opportunity on the red planet's surface.

Energy production for the Spirit increased almost 12 percent, from 261 to 295 watt hours per martian day, or "sol," and from 128 to 243 watt hours for Opportunity, a boost of nearly 53 percent. One hundred watt hours is what it takes to run a 100-watt light bulb for one hour. Before power production was impaired by the dust storms, the rovers were averaging about 700 watt hours per sol.

Opportunity has managed to fully charge its batteries and Spirit is bringing its batteries to nearly full charge. Also, the temperature of the core electronics module on Opportunity has risen from a dangerously low minus 25 degrees Fahrenheit (minus 37 Celsius) last week to minus 28.1 degrees Fahrenheit (minus 33.4 Celsius).

Mission controllers responded to the good news by gradually increasing the rovers' science observations. They have commanded Spirit to move its arm for the first time in nearly three weeks. The robotic geologist will position its arm's microscopic imager to take a series of photographs of two soil targets and one rock target.

Opportunity, currently perched on the rim of Victoria Crater where it was supposed to descend before the storms struck, will make scientific observations of the martian atmosphere.

John Callas, rover project manager at NASA's Jet Propulsion Laboratory in California, cautioned that the rovers are not fully in the clear yet.

"Conditions are still dangerous for both rovers and could get worse before things get better," Callas said. "We will continue our cautious approach to the weather and configure the rovers to maintain a high state of charge on the batteries. Communication sessions with both rovers will remain limited until the skies clear further."

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