[meteorite-list] Use of Curiosity Rover Arm Expected to Resume in a Few Days

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 6 Mar 2015 13:43:43 -0800 (PST)
Message-ID: <201503062143.t26LhhdC003862_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?feature=4504

Use of Rover Arm Expected to Resume in a Few Days
Jet Propulsion Laboratory
March 6, 2015

Mission Status Report

Managers of NASA's Curiosity Mars rover mission expect to approve resumption
of rover arm movements as early as next week while continuing analysis
of what appears to be an intermittent short circuit in the drill.

A fluctuation in current on Feb. 27 triggered a fault-protection response
that immediately halted action by the rover during the mission's 911th
Martian day, or sol. Since then, the rover team has avoided driving Curiosity
or moving the rover's arm, while engineers have focused on diagnostic
tests. Science observations with instruments on the rover's mast have
continued, along with environmental monitoring by its weather station.

"Diagnostic testing this week has been productive in narrowing the possible
sources of the transient short circuit," said Curiosity Project Manager
Jim Erickson of NASA's Jet Propulsion Laboratory, Pasadena, California.
"The most likely cause is an intermittent short in the percussion mechanism
of the drill. After further analysis to confirm that diagnosis, we will
be analyzing how to adjust for that in future drilling."

The sample-collection drill on Curiosity's robotic arm uses both rotation
and hammering, or percussion, to penetrate into Martian rocks and collect
pulverized rock material for delivery to analytical instruments inside
the rover.

The short on Sol 911 occurred while the rover was transferring rock-powder
sample from the grooves of the drill into a mechanism that sieves and
portions the powder. The percussion action was in use, to shake the powder
loose from the drill.

Engineers received results Thursday, March 5, from a test on Curiosity
that similarly used the drill's percussion action. During the third out
of 180 up-and-down repeats of the action, an apparent short circuit occurred
for less than one one-hundredth of a second. Though small and fleeting,
it would have been enough to trigger the fault protection that was active
on Sol 911 under the parameters that were in place then.

The rover team plans further testing to characterize the intermittent
short before the arm is moved from its present position, in case the short
does not appear when the orientation is different.

After those tests, the team expects to finish processing the sample powder
that the arm currently holds and then to deliver portions of the sample
to onboard laboratory instruments. Next, Curiosity will resume climbing
Mount Sharp.

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

http://mars.jpl.nasa.gov/msl/

You can follow the mission on Facebook and Twitter at:

http://www.facebook.com/marscuriosity

http://www.twitter.com/marscuriosity

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

2015-081
Received on Fri 06 Mar 2015 04:43:43 PM PST