The final several sols of Curiosity's drill activities at "Duluth" are devoted mostly to imaging and to analysis of the pile of drill tailings that are dumped on the ground after the delivery to the instruments.

Some people think dirt is uninteresting. Shortly after the Curiosity rover landed in 2012 I was asked to give a special talk to a very distinguished group of people. The slides had to be prepared a couple of weeks in advance and were sent from my director's office to be reviewed by handlers in the state where I was to give the talk. Those first days of the mission were breathtaking, and my presentation included the video of the landing, taken from the MARDI camera, mounted on belly of the rover, as it descended. In that scene, the dust gets kicked up by the sky crane's rocket engines as the rover nears the ground, and eventually the picture becomes rather dark as the rover's shadow covers the ground, but the first precious glimpse of a few pebbles can be made out, signaling a safe landing on an exciting new terrain!

I was in the middle of operations a couple of days after submitting the presentation when I noticed that I had just missed multiple phone calls. It turns out that the handler didn't like some parts of my presentation. Word was passed on to administrators at my institution: "You have to get rid of that video--it just shows a bunch of dirt!" I got on the phone and calmly explained that the offending sequence was in fact the very first Mars-landing video. My manager nearly fell off his chair laughing when he learned what it was. The person who didn't like the landing video probably would have equally disliked (or mistaken) a video of the first Moon landing, which also set down on "just a bunch of dirt."

Tosol Curiosity's "bunch of dirt" is the dump pile consisting of drill tailings as seen in the MAHLI image above (roughly 16.3 by 12.2 cm in dimensions), and the tailings bunched around the drill hole itself. The rover starts its science activities with Mastcam and ChemCam passive multispectral observations of the dump pile, and Mastcam and ChemCam active interrogation of target "Elbow Creek" (a vein). The arm then moves MAHLI into position to get 25 and 5 cm close-ups of the drill hole and the surrounding tailings. In the evening MAHLI gets turned on again to do nighttime imaging of the CheMin inlet on the deck of the rover, and then it goes back to the surface for nighttime imaging of the drill hole. After that, APXS is placed in position on the dump pile for an overnight integration. In between these activities the rover will continue observing the dust and surroundings: Mastcam continues a change-detection series of daily observations of the nearby surface, as well as looking at the observation tray and getting a view out to the crater rim. RAD, DAN, and REMS continue their daily investigations, as usual.

On Earth we have multiple means of communication-cell phone, text messages, land line, e-mail, and good old snail mail. On Mars the rover basically has three-a UHF antenna that communicates with satellites orbiting Mars, a low-gain antenna (LGA) that does not need to be pointed but only handles a low data flow, and a high-gain antenna (HGA) that requires accurate knowledge of Earth's position to receive or send commands directly. The two antennae on the left side of the rover are shown in the image above, taken early in the mission. The LGA is the pointy object near the left, and the HGA is the paddle-shaped object near the center of the image. The UHF antenna (not shown) is a can-shaped object on the back right side of the rover. Over the weekend the HGA was left unavailable to receive commands due to an error during a test, so the team had to do the next best thing yestersol, skipping most of the normal plan in order to reset the HGA-a bit like someone on Earth having to resort to a text message on an intermittent cell connection when an hours-long conversation was desired. As of today, it looks like Curiosity is back on track with normal communications.

Just to continue the discussion, on the downlink side, thanks to the combination of the HGA, orbiting satellites, and the Deep Space Network on Earth, we have received an average of about 60 megabytes of data each day from Curiosity over the last several years. We take that data link for granted when all is working well!

Back on the ground, Curiosity is resuming its drill-related activities with the plan to dump the tailings that are remaining in the drill. The sample dump is scheduled to take place in the early afternoon. Afterwards, the dump pile will be observed by Mastcam and MAHLI, and APXS will do an overnight integration on the pile. These analyses allow the rover team to determine the chemical composition of the drill material for comparison with the mineral composition obtained by CheMin. Having both chemical and mineral compositions helps us understand the origin of the rock and the conditions prevailing at the time of its formation much better than one data set by itself. Also happening during the day: ChemCam will shoot a couple of unrelated targets, "Robinson Lake" (nearby pebbles) and "Tofte" (a vein), both of which will also be observed by Mastcam. Imagers will also perform observations looking for dust devils and day-to-day changes in the nearby surface, as well as viewing the sky and the crater rim to characterize the increasing haze due to the dust storm. Observations of the environment by REMS, RAD, and DAN will continue.

Over the weekend, an error cropped up during a regular test of the high gain antenna actuators, leaving the antenna unavailable for uplink of today's plan, but otherwise healthy. The team instead will use Mars Reconnaissance Orbiter (MRO) to uplink a brief suite of activities to the rover, including the commands to recover the high gain antenna for use tomorrow. The MRO uplink window is hours later than our usual HGA uplink window, so with less time in the plan, we had to postpone our drill-related activities until tomorrow's plan. We did get confirmation that we are ready for the next step of drill-related activities: dumping the "Duluth" sample for analysis by APXS, MAHLI, ChemCam and Mastcam. For today, the high-priority activities that were included in the plan focused on monitoring the changing conditions associated with the ever-growing dust storm on Mars. Mastcam will measure the dust load in the atmosphere, and image two areas, "Noodle Lake" and a spot where a test Duluth sample portion was dropped, to look for wind-induced changes. Regular REMS measurements will give us the data we need for weather reports as the storm builds.

Today we planned a weekend's worth of activities for Curiosity. For our weekend plan, we have two main priorities: perform another analysis with CheMin on our Duluth drill sample and continue our campaign of dust storm monitoring.

Earlier in the week, our environmental science theme group (ENV) expert Scott Guzewich gave a nice summary of the dust storm developing on the other side of Mars. In response, the ENV group planned a suite of activities to monitor how the amount of dust in the atmosphere will change over the next few sols. To measure dust in the atmosphere, we'll first point Mastcam towards the sun and take a tau measurement, which lets us determine the optical depth vertically. Then we'll take a Mastcam image of the crater rim to determine line-of-sight extinction, which is directly related to the amount of dust present. ENV will also take a few movies with Navcam to assess clouds, wind direction, and to look for dust devils.

Overnight on Sol 2076-2077, we'll perform our third CheMin analysis on the Duluth drill sample. Our geology theme group (GEO) planned some additional activities later in the day on Sol 2077 to support our assessment of the Duluth drill hole, including a ChemCam LIBS raster of the drill hole and several change detection Mastcam images. Whenever Curiosity is parked at a location for more than a few sols, we commonly take a series of these change detection images to systematically look for material that has moved. We'll also do a LIBS observation on the nearby rock target "Isanti" and perform a routine check-up on the Mastcam instrument with a sky column observation.

Today, Sol 2075, was a fairly straightforward day of planning, as most of the plan will be devoted to carrying out a methane experiment with our SAM instrument to analyze an atmospheric sample. On the plus side, we were able to squeeze in about 45 minutes of additional science block time, which was split between our Environmental (ENV) and Geologic (GEO) theme groups. ENV will perform several atmospheric monitoring activities to assess dust opacity with Navcam and Mastcam, including a few line-of-sight images and a tau measurement. ENV will also take a series of images with Navcam to look for dust devils as well as a deck monitoring image with Mastcam.

GEO planned a ChemCam LIBS observation on the nodular target "Little Marais," which is seen in the RMI image above. We analyzed Little Marais on Sol 2074 and are carrying out an additional LIBS observation in today's plan to help us further characterize the chemistry of this interesting feature. ChemCam will also take an RMI image of the Duluth drill hole, which will help us plan additional drill hole targeting over the weekend.

Today we received the happy news that the SAM instrument received enough sample to conduct its "evolved gas" analysis of the powdered rock from our "Duluth" drill hole! This will allow the team to study the composition of "Duluth" and search for clues about the habitability of Gale Crater billions of years ago. It also fully validates the new sample drop off routines that were created to work with our new "feed-extended drilling" technique.

After a busy several sols where Curiosity's onboard laboratories got back in action, the plan today was relatively quiet with ChemCam LIBS analysis of rock targets "Little Marais" and "Independence", and some housekeeping activities from SAM following its investigations two sols ago.

The environmental science theme group is monitoring a growing large dust storm on the other side of Mars. To help keep tabs on if and when this storm begins to impact Gale Crater, we added two observations with Mastcam to monitor the amount of dust in the atmosphere and a short Navcam dust devil survey. We expect that even if the storm dissipates before becoming a global dust storm, that the amount of dust in Gale will increase over the next several days and this view of the crater's rim will become far hazier.

We received confirmation that the "Duluth" drill sample was delivered to SAM this weekend, so we're ready to run our evolved gas analysis (EGA) tosol! An EGA basically involves baking the powdered rock sample in a several hundred degree oven, and then measuring the amount and composition of gases that are liberated. Since running the oven requires so much power, we didn't have the resources to do a whole lot of additional activities in the sol 2072 plan. We did manage to fit in two science blocks that include a ChemCam observation of the target "Bartlett" (we missed acquiring this in the weekend, so will try again), a Navcam dust devil movie, a tau (atmospheric dust) observation, a Mastcam change detection image of the drill taillings pile, and Mastcam 360 degree mosaic to provide color context for the drill sample location.

The focus of MSL operations continues to be on the analysis of the Duluth drill sample. The latest SAM EGA was scheduled for the evening of Sol 2072, so the results of that analysis have not been received yet. Both SAM and CheMin analyses require significant power, and can therefore not typically be scheduled on the same day. So today it's CheMin's turn to analyze the the Duluth sample again, to improve the statistics of the X-ray diffraction measurements. The uplink team was also able to squeeze in a few daytime observations before the overnight CheMin analysis: Right Mastcam images of Noodle Lake, the Duluth drill tailings, and the portion drop area to look for changes due to winds, Mastcam images of the Sun to measure dust opacity, and a Navcam zenith movie to look for clouds. These observations should be helpful in determining the frequency, strength, and direction of winds near the surface and high above the rover. Such information will be very useful if the science team decides to drop another sample portion into either CheMin or SAM using the new sample transfer technique, as high winds can disperse the portion before it makes it into the instruments.

Image: The drill bit positioned over the CheMin inlet as part of the new FEST drop-off technique.

Every single day that the Curiosity team gets to go into work and operate a one-ton rover on the surface of Mars is a good day. But last Friday was not just your typical good day -- it was a very, very, very good day. In my personal opinion, it was probably one of the top five most excellent planning days we've had on the mission to date. Early Friday morning we learned that the Feed Extended Sample Transfer (FEST) drop-off of the "Duluth" drill sample to CheMin worked. This means we had enough rock powder in the instrument to measure its mineralogy.

Most importantly, now that we've demonstrated this critical step on Mars, the team can officially say that Curiosity's drilling and sample transfer capabilities have been restored. This represents a huge accomplishment for the tireless engineers who've worked over a year to learn to operate the vehicle in a way it was never designed to work. It's also an extremely exciting time for the science team, as we are eager to learn the key information CheMin and SAM will provide and further unravel the history of Gale Crater. The scientists and engineers at JPL celebrated this accomplishment with a joyous afternoon cookie break.

We will continue our Duluth drill sample analysis activities in the sol 2070-2072 plan. Since we now know we have successfully delivered to CheMin, SAM is up next. Our main activity for the weekend plan was a preconditioning of SAM and the sample dropoff using the FEST technique. We also squeezed in some remote sensing science of our local area. On sol 2070 we planned to acquire ChemCam LIBS observations of targets named "Little Marais" and "Bartlett," and a Mastcam change detection image of an area where we dropped a previous portion of the drill sample on the ground. We also planned to take a Mastcam tau (dust monitoring) observation on sol 2070, followed up with a Navcam dust devil movie, dust devil survey, and suprahorizon and zenith movies on sol 2071.

We're looking forward to analyzing some great drill samples from the "Duluth" rock target in Curiosity's Chemistry and Mineralogy instrument, CheMin. However, previous tests on Mars and the first delivery attempt to CheMin raised a concern that less material than expected may be making it in. To increase the chances of a successful CheMin analysis this time around, three portions will be delivered in Sol 2068 instead of the usual single portion, and from a smaller height than before.

In addition to the CheMin triple delivery, the geology theme group planned some passive imaging of target "Bassett" by ChemCam. This is exposed Murray formation bedrock, so the purpose is to compare its chemical composition with other Murray targets and get a sense of their variability. Also included were Mastcam stereo images of targets "Anderson Lake," "Bob Lake," "Toohey Lake," and "Bass Lake" to better understand the bedding geometry. The GEO theme group also included more Mastcam change detection images of the Duluth drill tailings and "Noodle Lake" target, to monitor how rapidly and in what direction the Martian wind is moving loose material on the surface.

The environmental theme group planned two early morning Navcam cloud movies on Sol 2069 less than an hour after sunrise. The cooler early morning is now the best time to see clouds, as we move well past the 'cloudy' season and into the warmer half of the year. These movies were followed by Mastcam images of the sky and crater rim, which respectively allow us to measure the opacity of the atmospheric column above the rover and the line-of-sight extinction across the crater horizontally. The air can be pretty dusty inside the crater, reducing visibility, even when no storms are raging, as shown in this Mastcam crater rim image from Sol 2065. The ENV theme group also took another long Navcam dust devil movie, this time looking more to the northeast, as well as a shorter movie looking to the northwest and another Navcam dust devil survey, with the two movies covered nicely by two hours of extended REMS meteorological measurements. Such overlap is ideal, because rapid pressure drops measured with REMS - which indicate a convective vortex (dusty or not!) passing nearby - can then be correlated with any dust devils we spot in the movies. This tells us something about how intense vortex activity has to be to raise dust and make vortices visible as dust devils. And on the rare occasions when we can connect a REMS pressure drop to a specific dust devil, we can use this to learn more about the dust devil's size and speed.