I was SOWG Chair early last week, when we planned the mini drill hole . This complex operation required many hours for the tactical team to plan and review, so I was pretty exhausted when we were done. I've also had a lot of other business and personal work to do, so it's been difficult for me to blog lately. The big news today is that the full drill hole was successfully completed ! The next steps will be to drop of samples of the new material to CheMin and SAM.

The data returned from Sol 610 showed that the rover is stable, so the weekend plan includes lots of arm activities. On Sol 612, APXS and MAHLI will study the planned drill target before the Dust Removal Tool (DRT) brushes it off. Then MAHLI will image the brushed area before the APXS is placed on it for an overnight integration. On Sol 613, MAHLI will take another selfie of the rover (similar to this image ), then pre-load the arm on the drill target. Sol 614 includes lots of remote sensing observations by ChemCam, Mastcam and Navcam. I wasn't on shift today, but followed along because I'll be SOWG Chair on Monday.

The rover bump went well, and the selected drill target is within reach. So the science team started planning various observations of the target, including MAHLI and APXS, to document its chemical composition and morphology before drilling. However, there were enough concerns about the rover slipping during arm activities that the MAHLI and APXS observations were removed from the plan. More data, needed to confirm that the rover is stable, are expected this afternoon. Hopefully, analysis of these data will show that it is safe to proceed with contact science.

The Sol 610 plan contains fairly simple, untargeted observations, including Mastcam and Navcam mosaics and a series of Navcam images of the western sky right after the sun sets behind Mt. Remarkable. Overnight, ChemCam will point at the dark sky and obtain calibration data, measuring thermal noise.

Sol 608 Planning: The drive and other activities planned for last weekend went well, and lots of nice images of the outcrop in front of the rover were received early Monday morning. While the strategic rover planners analyzed the data and began evaluating various candidate drill targets, the tactical team planned lots of ChemCam and Mastcam observations of the candidates. Later in the day, the rover planners and scientists discussed the drill options, and selected a flat outcrop about 4 meters away, shown in the upper right part of this image .
The goal for Sol 609 will be to bump the rover toward this outcrop, into a position that will allow drilling into it.

Sol 609 Planning: I'm MAHLI/MARDI uplink lead today, planning Sol 609. After ChemCam observations of targets Jarrad and Cow Bore , the rover will take another set of MAHLI images of the wheels, then bump a couple meters to get into position for contact science and drilling. Planning is restricted, so we won't receive the post-drive data until early Thursday. It was an easy planning day for me, as the end-of-drive MAHLI stowed image and MARDI twilight image have become routine.

I was scheduled as MAHLI/MARDI uplink lead last Friday, so I stayed an extra day in Pasadena after the MSL team meeting and worked at JPL. It's always easier to work on tactical operations at JPL, and Friday was no exception as we planned contact science on the windblown soil in front of the rover. I spent some time with the rover planners laying out MAHLI images of the soil target that was also measured by APXS on Sol 605. Another drive toward potential drill targets was planned for Sol 606, followed by untargeted remote sensing on Sol 607.

Thursday was the last day of the MSL science team meeting, and the discussion shifted from science results to analysis of wheel wear, both on Mars and on Earth. The engineers at JPL have done a lot of testing in the Mars Yard and compared the results with the many images of the wheels on Mars. Although these images show that wheel wear continues, the damage is accumulating at a lower rate due to the changes in traverse planning that have been implemented in the past few months. Driving over rough terrain appears to be the most significant threat to the wheels, and efforts to recognize and avoid hazardous terrain using data returned by Mars orbiters have allowed safer drive paths to be chosen. It was clear that the engineers are not as concerned about wheel wear as they were last fall, and that they do not feel that wheel wear will limit the lifetime of rover mobility. This conclusion was based in part on tests in the JPL Mars Yard that showed that even very heavily damaged wheels performed well in climbing rocky and sandy slopes.

While most of the MSL science team met at Caltech to discuss recent results and plans for the near future, the tactical team planned a 65-meter drive toward the southeastern side of Mount Remarkable, near the site chosen for the next drilling campaign. The rover will pause in the middle of the drive to image the backup drill site, then acquire all the data needed to select contact science targets and bump to a drill site this weekend. Planning is restricted again, so untargeted science will be planned for Sol 604.

I'm attending a 3-day meeting of the full MSL science team, so I'm less focused on rover operations than usual this week. After lots of interesting discussion of scientific data and hypotheses today, we did spend some time discussing where to drill and acquire a rock sample. The choices have been narrowed down to two locations on the flank of the hill called Mount Remarkable (at upper left, here ). The scientific advantages of the two sites were discussed, and there were no major differences identified. But getting to one of the sites would involve driving over rough, rocky terrain that might damage the wheels, so that site was not favored.

On April 14th, Mars made its closest approach to Earth this year. In addition, by chance, Earth's moon is totally eclipsed on the same night, very close in the sky to similarly red Mars. What a beautiful sight! Mars' proximity to Earth makes radio communications easier in general, but relay of data from MSL through the Mars orbiters to Earth is primarily constrained by the position of the orbiters in the sky over MSL. Communication from Earth to MSL is more affected by the Mars-Earth distance, but despite the close approach there was another problem sending commands to the rover last weekend, and therefore the planned contact science and drive did not occur.