Another busy 2-sol plan--Sol 544 will begin with a bunch of MAHLI activities: Imaging of the inlet for SAM's tunable laser spectrometer, the standard wheel imaging, and images from various angles of a spot in front of the rover to measure the photometric behavior of the surface. The first and last activities have been desired since early in the mission, so it's good to finally plan them. After stowing the arm, Mastcam and ChemCam will observe targets "Sandy Dam" and "Nita." Before sunrise on Sol 545, ChemCam will search for condensed water. Then the rover will drive about 50 meters and take the post-drive images needed to plan a full set of wheel images on Sol 546.

I'm SOWG Chair again for another 2-sol plan, and it's been a more hectic planning day. The Sol 540 drive went well, about 71 meters total. A shorter (~23 m) drive is planned for Sol 542, allowing some time for pre-drive targeted Mastcam stereo imaging and MAHLI images of the wheels. Because the volume of data expected to arrive in time for planning on Friday is limited, it was a challenge to prioritize all of the necessary data. Another challenge was including a Mastcam search for frost at sunrise on Sol 543 without depleting the battery too much. In the end, we got everything to fit, plus a bunch of untargeted ChemCam and Mastcam observations later on Sol 543.

The Sol 533 toe dip went well, leaving the rover's front wheels on the crest of the dune . The Sol 534 plan was to drive over dune into Dingo Gap, but late in the day it was cancelled. The Rover Drivers had some concerns about the terrain and it was decided that delay the drive to Sol 535 in order to give them more time to plan the drive.

The initial "toe dip" into the dune in Dingo Gap was planned for Sol 533. If it goes well, the rover will be commanded to cross the dune, probably on the left (south) side, on Sol 534. I'm catching up on the latest MSL plans after spending the day working MER tactical operations as MI/engineering camera uplink lead. Opportunity is also planning a short drive, followed by imaging of the previous rover location to determine whether the rover wheels dislodged and flipped over the unique-looking rock, Pinnacle Island .

In order to learn more about the sand dune in Dingo Gap , the rover will be commanded to drive up to it on Sol 528. Mobility tests on terrestrial sand dunes show that MSL can climb dunes, but we don't yet know that the feature in front of MSL is sandy throughout. Opportunity got stuck in Purgatory Dune for a few weeks, in part because it contained more fine grained dust than typical terrestrial dunes. So MSL will study the interior structure of the Martian dune before driving over it. There is also a concern that Dingo Gap is deep enough that radio communications directly to/from Earth via the high gain antenna may be affected, so post-drive images looking over the dune into the gap are planned to better assess the terrain.

MSL drove about 15 meters toward Dingo Gap and returned post-drive images that were used to plan ChemCam RMI and Mastcam images from the new location. The Sol 527 plan also includes another drive toward Dingo Gap and reprocessing of some CheMin data. The post-drive data will be used to determine which way to go on Sol 528, in particular whether to drive over the dune in the gap.

I'm SOWG Chair again today, planning Sol 513, which will be dominated by a full set of MAHLI images of wheels. The images will be taken between short drives, to turn the wheels a bit and allow the entire surfaces of the wheels to be imaged. This will require a fair amount of power, so the main constraint on science planning was ensuring that we don't take too much charge out of the battery. But we were still able to add some post-drive science, including a DAN active measurement of hydrogen below the surface, a Navcam cloud search, and the usual imaging needed to plan targeted observations on Sol 514. The command sequences must be sent to the rover by about 5 PM Pacific time, so planning started 1.5 hours earlier than usual--not as early as yesterday though, when it was still dark when I drove in to work.

The weekend activities executed as planned, and the rover is in a good location to start a full campaign of wheel imaging. Originally, a short drive or "bump" was planned for Sol 512 to get the rover in position for wheel imaging. Because this bump was not needed, more time was available for contact science. This meant the Science Theme Groups and I (as SOWG Chair) had a hectic morning, preparing for both contingencies as the rover planners evaluated the data to determine whether the bump was needed. We ended up adding an additional APXS/MAHLI target for contact science, including an overnight APXS integration on "Kodak." Planning is unrestricted this week, and due to the timing of the uplink we had to start earlier than usual, at 6:00 Pacific time this morning.

The CheMin data processing planned for Sol 505 was deleted from the plan, but SAM made another measurement of the atmosphere that night. The Sol 504 drive went well, and the rover is in a stable position, so a "touch and go" is planned for Sol 506. First, MAHLI images and APXS data will be acquired on a rock named "Oneida" in front of the rover. Then the rover will drive about 26 meters and take the usual post-drive images to allow planning the next drive and new scientific activities. Images of the wheels will be taken both during and after the drive.

I'll be traveling starting tomorrow to a meeting of the MER science team in Maryland, so it will be difficult for me to follow MSL's progress this week. But I'm looking forward to discussing the latest Opportunity results and celebrating the 10th anniversary of the MER landings .

The MSL tactical operations team is fully re-engaged after the holiday break, planning a bunch of activities to keep the rover busy this weekend. Sol 503 starts with remote sensing observations, followed by MAHLI and APXS measurements of a couple of targets in front of the rover. Sol 504 is dominated by driving, with new MAHLI and Mastcam images of the wheels. Finally, untargeted remote sensing and CheMin data processing are planned for Sol 505.

As was noted during both MER and MSL SOWG meetings today, January 3rd is the 10th anniversary of Spirit's successful landing on Mars. No data have been received from Spirit since March 2010, but Opportunity is still operating!