Power drain threatening Mars rover
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The semi-circular depression on the right side of this microscopic image resulted from Opportunity's grinding of a Martian rock February 23, 2004.
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LOS ANGELES, California (Reuters) -- Engineers must replace software in the Mars rover Opportunity to stop a power-draining malfunction that could cut short the robot geologist's life on the red planet, a NASA official said on Wednesday.
A switch that operates an onboard heater has been stuck in the "on" position since shortly after the golf cart-sized rover landed at the Meridiani Planum near Mars' equator on January 24.
The malfunction has not affected the rover's ability to move or do science experiments but is a constant drain on the vehicle's solar-powered batteries, project manager Richard Cook told reporters on Wednesday.
"The amount of power per day is slowly dropping," Cook said. "[The switch] consumes a sizable amount of energy every day. Opportunity is shortening down its day of operations as we move forward."
Cook said engineers planned to upload new software to Opportunity in about a month that will shut off a few minor systems that now stay on during its overnight "sleep" mode.
"We essentially are removing the power source from this ... heater. We will turn it off by removing the power source it uses," Cook said. The new system will recapture about two-thirds of the energy now lost to the malfunction, he added.
The new software removes the rover's internal "alarm clock" -- one of the systems for "waking up" the rover to begin a day's operations. The vehicle also is designed to power up when the sun shines on its solar arrays. "It's sort of a belt and suspenders situation and we are removing one of those," Cook said.
Opportunity is examining an outcrop of finely layered bedrock that scientists believe holds clues to the planet's composition.
The rover spent its 31st Martian day, or sol, ending early Wednesday, charging its batteries and beaming back scientific data about a rock it drilled into one sol earlier to scientists at NASA's Jet Propulsion Laboratory in Pasadena, California.
Its twin, Spirit, got stuck on the lip of a shallow crater nicknamed "Middle Ground" where it stopped overnight on its 52nd day on Mars.
Spirit landed on January 3 in the Gusev Crater, a depression the size of Connecticut that scientists believe is an ancient lake bed. The rover has driven 135 meters (443 feet) from its landing site searching for rocks and soil that were deposited or smoothed long ago by water.
Spirit now is headed toward a small impact crater nicknamed Bonneville Crater, where scientists hope to find rocks ejected from deep below the planet's surface, where evidence of water may have been buried by a subsequent lava floe, Cook said.
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