Astrogeology Science Center

Sol 11 update on Curiosity from USGS Scientist Ken Herkenhoff: ChemCam Testing

16 August 2012
I served as SOWG chair again today, planning Sol 11 of the MSL mission.
All is going well, but slowly--we continue to confirm that instruments are
working and to get ready for more ambitious activities.  Today's plan was
so full of stuff that we have to do to realize the full potential of MSL
that we couldn't add new observations based on the data we have received so
far.  For example, a full hour of the day was spent setting software
parameters for all the motors on the rover--thousands of parameters!  This
is indeed a very complex system.  But the rover is healthy and the planning
team is getting better at preparing ever more complicated command sequences
to send to MSL.

The most exciting news today was that the ChemCam and Chemin instruments
successfully returned their first data.  ChemCam is the remote chemical
analysis instrument that uses a laser to vaporize rock/soil up to 7 meters
away, creating a plasma of ions and excited atoms that emit photons as
their electrons relax to lower energy states.  These "electronic
transitions" are measured by sensitive spectrometers, yielding spectral
peaks that indicate which elements are present in the target.  In
preparation for such observations, we tested the pointing of the instrument
by taking pictures of a calibration target on the rover with the Remote
Microscopic Imager (RMI), a camera that uses the same optics as the laser
and spectrometers to show where the laser hit the target.  We didn't fire
the laser yet, because we want to be sure that the pointing is accurate
first.  We wouldn't want to shoot the rover by mistake!  But the RMI images
show that the pointing is very good, and they will allow us to improve the
pointing by analyzing the offsets relative to the center of the calibration
target.  Most importantly, both ChemCam and Chemin (the X-ray instrument
that will determine what minerals are present in samples delivered to it)
are working as well as expected--everyone applauded when the initial
results were reported!

Ken