[meteorite-list] Wheel Concerns Prompt New Route for Mars Rover Curiosity

[Ron Baalke]

http://www.spaceflightnow.com/mars/msl/140218dunes/

Wheel concerns prompt new route for Mars rover
BY STEPHEN CLARK
SPACEFLIGHT NOW
February 18, 2014

Planners in charge of plotting the course of NASA's Curiosity rover, which 
is trekking toward a massive mountain on the red planet, have selected 
a route with fewer rock hazards in lieu of alternate paths that could 
exacerbate damage to the robot's wheels.

The rover traversed a dune in early February to take a southwestward route 
toward the rover's next science target, a junction of different rock types 
where scientists are considering using the rover's drill.

The 3-foot-tall dune spanned two scarps along a ridge marking the eastern 
edge of a valley.

The path avoids sharp rocks that could further damage the rover's wheels, 
but dunes present their own dangers. NASA's earlier Mars rovers, Spirit 
and Opportunity, were trapped in sand dunes.

Opportunity was able to break free a dune after more than a month of immobility 
in 2005, but Spirit was mired in a sand trap tilted away from the sun 
during a Martian winter, dooming the rover when it was unable to generate 
enough power to stay alive.

Engineers noticed the damage on Curiosity's six wheels last year. They 
expected the rover to accumulate dings at it scraped over rocks, but the 
wear and tear observed on the rover's wheels was greater than they anticipated 
less than a year-and-a-half since landing.

Officials have occasionally inspected Curiosity's damage with the rover's 
robotic arm camera, revealing several holes in the aluminum wheels.

[Image]
This image taken by the Curiosity's rover's robotic arm camera shows scuffs 
and holes in one of its six aluminum wheels. Credit: NASA/JPL-Caltech/MSSS
 
The discovery prompted managers at the Jet Propulsion Laboratory in California 
to seek more favorable ground for the next phase of Curiosity's drive 
toward Mount Sharp, a three-mile-high peak inside Gale crater, the rover's 
landing site.

Curiosity's odometer recently crossed 3 miles, with several miles still 
to go before reaching Mount Sharp. Scientists expect the rover to arrive 
at its base some time this summer.

Observations from sensors mounted on orbiters indicate Mount Sharp harbors 
clay minerals likely deposited by water some time in Mars' ancient past. 
The clays line the mountain's foothills inside layered terrain already 
spotted from a distance by Curiosity's panoramic camera.

The rover's complex instrumentation has already explored an ancient riverbed, 
confirming the location could have once supported microbial life when 
Mars was warmer and wetter.