NASA's Mars rover Curiosity completed its first two-day autonomous
drive Monday, bringing the mobile laboratory to a good vantage point for
pictures useful in selecting the next target the rover will reach out
and touch.
When it drives autonomously, the rover chooses a safe route to
designated waypoints by using its onboard computer to analyze stereo
images that it takes during pauses in the drive. Prior to Monday, each
day’s autonomous drive came after a segment earlier that day that was
exactly charted by rover team members using images sent to Earth. The
Sunday-Monday drive was the first time Curiosity ended an autonomous
driving segment, then continued autonomously from that same point the
next day.
The drives brought Curiosity to about 262 feet (about 80 meters) from
"Cooperstown," an outcrop bearing candidate targets for examination
with instruments on the rover's arm. The moniker, appropriate for
baseball season, comes from a named rock deposit in New York. Curiosity
has not used its arm-mounted instruments to examine a target since
departing an outcrop called "Darwin" on Sept. 22. Researchers used the
arm's camera and spectrometer for four days at Darwin; they plan to use
them on just one day at Cooperstown.
Starting to use two-day autonomous driving and the shorter duration
planned for examining Cooperstown serve to accelerate Curiosity's
progress toward the mission's main destination: Mount Sharp.
In July, Curiosity began a trek of about 5.3 miles (8.6 kilometers),
starting from the area where it worked for the first half of 2013,
headed to an entry point to Mount Sharp. Cooperstown is about one-third
of the way along the route. The team used images from NASA's Mars
Reconnaissance Orbiter to plot the route and choose a few points of
potential special interest along the way, including Darwin and
Cooperstown.
"What interests us about this site is an intriguing outcrop of
layered material visible in the orbital images," said Kevin Lewis of
Princeton University, Princeton, N.J., a participating scientist for the
mission who has been a leader in planning the Cooperstown activities.
"We want to see how the local layered outcrop at Cooperstown may help us
relate the geology of Yellowknife Bay to the geology of Mount Sharp."
The team is using images taken from the vantage point reached on
Monday to decide what part of the Cooperstown outcrop to investigate
with the arm-mounted instruments.
The first day of the two-day drive began Sunday with about 180 feet
(55 meters) on a southwestward path that rover drivers at NASA's Jet
Propulsion Laboratory, Pasadena, Calif., evaluated ahead of time as
safe. The autonomous-driving portion began where that left off, with
Curiosity evaluating the best way to reach designated waypoints ahead.
The vehicle drove about 125 feet (38 meters) autonomously on Sunday.
"We needed to store some key variables in the rover's non-volatile
memory for the next day," said JPL rover driver John Wright. Curiosity's
volatile memory is cleared when the rover goes into energy-conserving
sleep mode overnight.
The stored variables included what direction the rover was driving
when it ended the first day's drive, and whether it had classified the
next 10 feet (3 meters) in that direction as safe for driving. When it
began its second day of driving, Curiosity resumed evaluating the
terrain ahead for safe driving and drove 105 feet (32 meters), all
autonomously.
This new capability enables driving extra days during multi-day
activity plans that the rover team develops on Fridays and before
holidays.
A key activity planned for the week of Nov. 4 is uploading a new
version of onboard software -- the third such upgrade since landing.
These upgrades allow continued advances in the rover's capabilities. The
version prepared for upload next week includes, for example,
improvements in what information the rover can store overnight to resume
autonomous driving the next day. It also expands capabilities for using
the robotic arm while parked on slopes. The team expects that to be
crucial for investigations on Mount Sharp.
JPL, a division of the California Institute of Technology in
Pasadena, manages the Mars Science Laboratory Project for NASA's Science
Mission Directorate, Washington. JPL designed and built the project's
Curiosity rover.
More information about Curiosity is online at 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 .
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