Sol 39 update on Curiosity from USGS Scientist Ken Herkenhoff: Driving Again15 September 2012
The drive went as planned, and left MSL next to a nice outcrop During the drive the DAN instrument monitored neutrons coming up from the subsurface and noticed significant variations along the way. It's not known (at least to me) what causes these variations, but possibilities include hydrated minerals, water ice (unlikely?), and density variations. Another drive is planned for Sol 39 (about 20 meters this time), so a bunch of images of the outcrop were planned before the drive. Unfortunately, we aren't expecting to get much data through the orbiters tomorrow, so we probably won't see these images for a while. Worse, we may not get enough Navcam images after the Sol 39 drive to plan more observations in the new location. The amount of data that can be relayed to the orbiters depends on how high in the sky they pass over MSL, which varies a lot day to day. In addition the Mars Reconnaissance Orbiter (MRO) is turning instruments back on, which may interfere with MSL radio communications. Therefore, telemetry rates are set low to ensure that we get at least some data while characterizing the radio link with the instruments turned on. Most of MRO's instruments were off during MSL landing to maximize the amount of data that could be relayed from MSL. The instruments are resuming scientific data collection after the hiatus for MSL.