[meteorite-list] Mars Rover Opportunity Update: August 19-25, 2015

[Ron Baalke]

OPPORTUNITY UPDATE: Brushing a Rock and In-Situ Studies, sols 4113-4119, 
August 19, 2015-August 25, 2018.

Opportunity is in 'Marathon Valley' on the west rim of Endeavour Crater 
exploring for phyllosilicate clay minerals. 

The rover is operating in persistent RAM mode (not using Flash for data 
storage). The rover is in the midst of a grind campaign on the surface 
target, 'Pvt. Robert Frazer.' On Sol 4114 (Aug. 20, 2015), Opportunity 
ground about 2.5 millimeters into the surface to expose fresh outcrop 
using the Rock Abrasion Tool (RAT) on the end of the robotic arm. This 
was to be followed on the next sol by a brushing to remove the grind tailings 
from the surface site. But, a sequencing error prevented the RAT from 
initiating the brush activity. The project diagnosed the problem on the 
Surface System Testbed (SSTB) rover at JPL and confirmed the corrective 
action. 

Meanwhile, the rover continued the remote sensing of the valley with several 
Panoramic Camera (Pancam) panoramas collected of the North Wall of Marathon 
Valley plus some 13-filter Pancam images of selected surface targets. 
An Alpha Particle X-ray Spectrometer APXS measurement of atmospheric argon 
was collected on the evening of Sol 4116 (Aug. 22, 2015). The plan ahead 
is to complete the brushing of the freshly ground surface target for detailed 
in-situ (contact) measurements. 

As of Sol 4119 (Aug. 25, 2015), the solar array energy production was 
404 watt-hours with an atmospheric opacity (Tau) of 0.652 and a solar 
array dust factor of 0.590.

Total odometry is 26.41 miles (42.51 kilometers), more than a marathon.