[meteorite-list] Curiosity Mars Rover Checking Possible Smoother Route

[Ron Baalke]

http://www.jpl.nasa.gov/news/news.php?release=2014-028

Curiosity Mars Rover Checking Possible Smoother Route
Jet Propulsion Laboratory
January 29, 2014

[Images]
    * Curiosity Mars Rover Approaches 'Dingo Gap,' Mastcam View
    * Full-Circle Vista During Curiosity's Approach to 'Dingo Gap' 
    * Full-Circle Vista During Curiosity's Approach to 'Dingo Gap' (Stereo) 
    * Traverse Map for Mars Rover Curiosity as of Jan. 26, 2014 
    * Crystal-Laden Martian Rock Examined by Curiosity's Laser Instrument 
    * Graph shows the cumulative total of pulses 


Mars Science Laboratory Mission Status Report

The team operating NASA's Mars rover Curiosity is considering a path
across a small sand dune to reach a favorable route to science destinations.

A favorable route would skirt some terrain with sharp rocks considered
more likely to poke holes in the rover's aluminum wheels.

While the team has been assessing ways to reduce wear and tear to the
wheels, Curiosity has made progress toward a next site for drilling a
rock sample and also toward its long-term destination: geological layers
exposed on slopes of Mount Sharp. The rover has driven into a mapping
quadrant that includes a candidate site for drilling. Meanwhile, testing
on Earth is validating capabilities for drilling into rocks on slopes
the rover will likely encounter on Mount Sharp.

Curiosity has driven 865 feet (264.7 meters) since Jan. 1, for a total
odometry of 3.04 miles (4.89 kilometers) since its August 2012 landing.

Accumulation of punctures and rips in the wheels accelerated in the
fourth quarter of 2013. Among the responses to that development, the
team now drives the rover with added precautions, thoroughly checks the
condition of Curiosity's wheels frequently, and is evaluating routes and
driving methods that could avoid some wheel damage.

A dune about 3 feet (1 meter) high spans the gap between two scarps that
might be a gateway to a southwestward route over relatively smooth
ground. Curiosity is approaching the site, "Dingo Gap," from the
southeast. The team is using images from the rover to assess whether to
cross the dune.

"The decision hasn't been made yet, but it is prudent to go check," said
Jim Erickson of NASA's Jet Propulsion Laboratory, Pasadena, Calif.,
project manager for Curiosity. "We'll take a peek over the dune into the
valley immediately to the west to see whether the terrain looks as good
as the analysis of orbital images implies." The orbital images come from
the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's
Mars Reconnaissance Orbiter.

Other routes have also been evaluated for getting Curiosity from the
rover's current location to a candidate drilling site called "KMS-9."
That site lies about half a mile (800 meters) away by straight line, but
considerably farther by any of the driving routes assessed.
Characteristics seen in orbital imagery of the site appeal to
Curiosity's science team. "At KMS-9, we see three terrain types exposed
and a relatively dust-free surface," said science team collaborator
Katie Stack of the California Institute of Technology, Pasadena.

Before Curiosity's landing inside Gale Crater, the mission's science
team used images from orbit to map terrain types in a grid of 140 square
quadrants, each about 0.9 mile (1.5 kilometers) wide. Curiosity landed
in the "Yellowknife" quadrant and subsequently crossed parts of
quadrants called "Mawson" and "Coeymans." This month, it entered the
"Kimberley" quadrant, home of KMS-9.

Stack said, "This area is appealing because we can see terrain units
unlike any that Curiosity has visited so far. One unit has striations
all oriented in a similar direction. Another is smooth, without
striations. We don't know yet what they are. The big draw is exploration
and seeing new things."

Science investigations have continued along with recent drives. One rock
examined on Jan. 15, "Harrison," revealed linear crystals with
feldspar-rich composition.

To prepare for destinations farther ahead, engineers are using a test
rover at JPL to check the rover's ability to tolerate slight slippage on
slopes while using its drill. With the drill bit in a rock, tests
simulating slips of up to about 2 inches (5 centimeters) have not caused
damage.

"These tests are building confidence for operations we are likely to use
when Curiosity is on the slopes of Mount Sharp," said JPL's Daniel
Limonadi, systems engineering leader for surface sampling with the
rover's arm.

Other testing at JPL is evaluating possible driving techniques that
might help reduce the rate of wheel punctures, such as driving backwards
or using four-wheel drive instead of six-wheel drive. Some of the wheel
damage may result from the force of rear wheels pushing middle or front
wheels against sharp rocks, rather than simply the weight of the rover
driving over the rocks.

"An analogy is when you are rolling your wheeled luggage over a curb,
you can feel the difference between trying to push it over the curb or
pull it over the curb," said JPL's Richard Rainen, mechanical
engineering team leader for Curiosity.

While continuing to evaluate routes and driving techniques, Curiosity's
team will add some weekend and evening shifts in February to enable
planning more drives than would otherwise be possible.

NASA's Mars Science Laboratory Project is using Curiosity to assess
ancient habitable environments and major changes in Martian
environmental conditions. JPL, a division of the California Institute of
Technology in Pasadena, built the rover and manages the project for
NASA's Science Mission Directorate in Washington. For more information
about Curiosity, visit http://www.nasa.gov/msl and
http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook
at http://www.facebook.com/marscuriosity and on Twitter at:
http://www.twitter.com/marscuriosity .

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

2013-028