I'm back from a week's vacation, catching up on everything that MSL has been doing. A new record for drive distance was set last week, 141 meters! Driving this far required lots of autonomous navigation, which left little time for science observations. Last weekend's plan included contact science (MAHLI and APXS) on rock outcrops and another drive toward "Waypoint 1," a location where more detailed studies are planned. If all goes well, the rover will be in position for contact science on the target "Darwin" tomorrow.

Autonomous navigation continues to work well, allowing longer drives into areas not visible from the previous rover location. Today the view ahead is good enough that we are planning to drive over 100 meters, with the last ~45 meters using AutoNav. But driving this far leaves very little time for targeted science observations, only a few minutes today. We knew that we would have to consider this trade off between observations and drive distance once AutoNav was verified on the B computer, but the decision is still painful. Some scientists want to spend more time studying interesting features during the long traverse to Aeolis Mons ("Mt. Sharp"), but Gale crater was selected as the MSL landing site so that the geologic history recorded in the layers of Aeolis Mons could be investigated. The overall science goal is to get to the base of the mountain with minimal delays.

The Sol 379 drive went well, and the rover is in a safe configuration for arm deployment. So we are planning 3 sols today (to get the rover through the Labor Day holiday), including drop-off of sample to SAM and overnight analysis, followed by a drive on the last sol. We packed some more observations into the plan, including ChemCam, DAN, and Mastcam, along with the usual post-drive imaging to set us up for the next drive. So it has been a busy day, but not as hectic as yesterday.

Autonomous navigation continues to work well, and Curiosity completed another long drive on Sol 378. However, the left rear wheel ended up on a ~6 cm rock, which is larger than allowed for safe deployment of the arm. The concern that the wheel might slip off the rock while the arm is moving around, perhaps damaging the arm, caused a change in plans. The original plan was to use the arm to drop more of the Cumberland drill sample into SAM for another evolved gas analysis (2 sols worth of activities). Instead, we decided to drive about 15 meters to an area with fewer large rocks and try again. So it was a hectic day for me as SOWG Chair, but we recovered nicely from the situation. If the drive goes well, we will have a better view of the path ahead. We are planning 2 sols today, then 3 sols tomorrow to get us through the Labor Day holiday weekend.

The Sol 374 drive, including the AutoNav portion, went very well, so an even longer drive is planned for Sol 376. For the first time AutoNav will be used to drive 10 meters over the hill, or beyond the area imaged in stereo by the Navcams after the Sol 374 drive. If the AutoNav software continues to perform well, allowing the rover to drive into areas that cannot be evaluated in advance, longer AutoNav drives will be allowed.

The autonomous navigation checkout, part of the Sol 372 drive, went perfectly! So "AutoNav" can be used for up to 90 minutes next time. If the software continues to work well, it will be used to drive into areas that cannot be seen from the rover (over hills, for example). The weekend plan includes lots of activities, including MAHLI and APXS observations of targets right in front of the rover on Sol 373, another long drive on Sol 374, and untargeted remote sensing on Sol 375. ChemCam RMI images of the sky, to check the "flat field" calibration of the camera, are also included.

The Sol 371 drive set a new MSL distance record for a single sol, 110 meters. The Sol 372 drive will be shorter, but includes the first test of autonomous navigation ("AutoNav") on the "B" computer. After the Sol 200 anomaly, when the rover swapped to the B computer, problems with the terrain meshes generated using the B Navcams were noted and additional camera calibration data acquired. These data have been analyzed and show that the pointing of the B Navcams (mounted below the A Navcams) varies slightly with temperature. The results have been modeled and used to update the flight software. Accounting for the thermal dependence of the B Navcam pointing has been particularly complex for the AutoNav software, which is now ready for flight testing. The Sol 372 AutoNav checkout is complicated by the desire to set up the rover for potential arm contact science observations this weekend.

The Sol 370 drive went well, and the rover stopped near an interesting outcrop . So we're planning as many observations as we can squeeze in before the next drive. Because we can see farther ahead of us than usual, the rover planners are planning to drive 100 meters or more. To allow this longer drive, some of the pre-drive science observations had to be deleted. In addition, we don't have time for the post-drive MAHLI stowed image. While removing these observations is frustrating, we all agree that driving has top priority.

After taking a week off from MSL tactical planning, I was back on shift as MAHLI/MARDI uplink lead yesterday, planning Sol 369. We are no longer restricted by the offset between Earth and Mars time, so we can plan drives every sol this week. After each drive, we continue to take MAHLI and MARDI images to document the changing terrain near the rover. However, the rover did not drive last weekend to allow SAM to make another measurement of the Cumberland drill sample; the SAM data have not all been received yet.

The Sol 356 drive went well, so another drive was planned for Sol 358. We are still "restricted," as the post-drive data will not arrive until 10 PM PDT tonight. So the Sol 359 plan includes only untargeted observations. The plan is therefore pretty simple, which is making for an easy SOWG Chair shift for me today.