If all had gone according to plan over the weekend, we would see a nice pile of drill fines in the above image. Alas, a slight hiccup in the sample dump process meant that the "Stoer" sample was still in the drill and turret. Fortunately, the vast majority of the weekend activities executed unhindered by the sample dumping fault, allowing the team to focus today on recovering the dump-related activities. We had enough power to reattempt the sample dump, the MAHLI imaging on the dump pile, and two APXS integrations on the dump pile. We planned Mastcam and Navcam images of the workspace after the sample is dumped to enable us to target the dump pile with ChemCam in the next couple of sols. A MAHLI image of the drill hole and tailings will help us plan APXS placement on the tailings as soon as tomorrow's plan.

In addition to making forward progress on drill activities, Curiosity continued to learn more about the dust kicked up by the now-waning dust storm conditions. A weekend dress rehearsal of a ChemCam passive observation of the Sun was successful, so today's plan included the complete observation. Typically, we avoid pointing ChemCam at the Sun (really, all cameras!), but this carefully designed observation will acquire ChemCam passive data that will characterize the spectral properties of the atmospheric dust kicked up by the dust storm.

Not bad for a Monday!

The big question coming into today was whether to re-do the SAM analysis or not. Now that the drill is being operated with the feed immobile in the extended position, the portions (amount of drill tailings) that are delivered to CheMin and SAM are less accurate than before. Duluth was the only previous drill attempt to reach sampling depth with the feed immobile. In that case several attempts were made to deliver proper portions to the in-situ instrument funnels.

Duluth drop-off story: https://mars.jpl.nasa.gov/msl/mission/mars-rover-curiosity-mission-updates/?mu=sol-2063-2066-sample-drop-off-testing

The accompanying image shows the positions of the SAM inlets on the rover deck, with the covers closed. The rover team seems to have learned quite quickly how to get the portions to these instruments, and this morning we learned that SAM completed a successful analysis. The other part of the decision was whether to repeat SAM's analysis with different parameters, but the team decided not to do so at this time, so now we can continue with the drill analysis sequence. That will include dumping the rest of the material so we can see how much was left in the drill chambers. The operation will be carried out using two dozen separate portion drop-off sequences with Mastcam images in between to check how much material comes out. I just watched an animated video of the sequence and it looks pretty cool. The arm swings down near the ground for each drop-off, then moves out of the way, and the mast points Mastcam to take an image. Then the mast turns away-to avoid any possible dust-while the arm swings down for the next drop off. Every drop-off is done in a slightly different location on rock surfaces, some being spaced 7 mm away from each other around a circle. Each little portion gets imaged.

Other activities planned for tosol include ChemCam bedrock target "Papa Little" and another ChemCam raster down the drill hole, with accompanying Mastcam documentation. There will also be half a dozen MARDI change-detection images spaced throughout the day. DAN, REMS, and RAD will continue taking data.

With seventeen sampling holes and several test holes, you might imagine that Curiosity is creating a rather long and erratic golf course in Gale crater. After all, Alan Shepard shot a golf ball on the Moon. The first two martian sampling holes, at Yellowknife Bay, are several kilometers away from the third hole, at Kimberley, which is several kilometers from all the subsequent ones in the Murray formation. The distances between the first several holes might be too long for golf links on Earth, but maybe with reduced gravity and very little wind resistance, a mighty drive of over a kilometer might be possible. Unfortunately, the size of the holes drilled by Curiosity, at ~16 mm diameter, are too small for golf balls, which are > 41 mm diameter, so golf enthusiasts will have to wait a little longer to play on Mars.

Curiosity continues to analyze the samples from the Stoer drill hole. The rover and arm are stationary until we receive a green light from SAM and CheMin analyses. The main activity today is more analysis time for CheMin, which will run in the background. In the meantime, ChemCam gets to shoot at "Ainshval," "Tarskavaig," and "Loch Aline," which are interesting vein and concretion features on the rock surface in the vicinity of the drill hole. Some of the recently-imaged vein material is shown in the accompanying RMI image. Mastcam will image the new targets and will also take another picture of the drill tailings. There are MARDI change-detection images just after sunset and just before sunrise tomorrow, DAN active and passive observations, a dust-devil survey by Navcam, and REMS and RAD data collects.

Curiosity is probing the subsurface today with its Dynamic Albedo of Neutrons (DAN) instrument. At three different times, Curiosity will use DAN in its "active" mode for 20 minutes, sending pulses of neutrons into the ground beneath the rover, and then listening for the neutrons that are scattered back to the instrument. Hydrogen atoms in water will reduce the energy of the neutrons, so the scattered signal that DAN receives will tell us about how much water might be present in the form of hydrated minerals and amorphous phases, to a depth of 1 m beneath the surface. Curiosity is using DAN multiple times today because the neutron output from the DAN Pulsing Neutron Generator (PNG) has decreased over time (though it is well beyond its expected life), and we hope that integrating over multiple intervals will give the same signal-to-noise ratio that DAN observations had at the start of Curiosity's mission.

In addition, Curiosity is performing more analyses of the "Stoer" sample and continues to characterize the region around the drill site. A major activity today is a second X-Ray Diffraction (XRD) analysis by the CheMin instrument, which will provide more detailed information about the mineralogy. Curiosity will also be firing up the ChemCam laser to examine two rock targets near the drill hole: "Mainland," which is 30 cm from the Stoer hole and will tell us about bedrock chemistry variations; and "Doonie_Point," which is about 1 m from the Stoer hole and might be a concretion in the bedrock.

With the successful drilling of the Stoer target two weeks ago, Curiosity has been busy characterizing the surrounding terrain using its remote instrument package, performing contact science in the immediate vicinity to understand the composition and physical nature of the bedrock, and also performing power-intensive lab-quality analyses of the Stoer sample using its onboard analytical instruments. In today's plan, Curiosity will perform an evolved gas analysis (EGA) on the Stoer sample using the Sample Analysis at Mars (SAM) instrument. EGA analyses are critical towards understanding the volatiles and organic molecules that may be present within the sample. SAM will heat the Stoer sample to very high temperatures, more than 900 degrees Celsius, and will measure the composition of gases (including H2O, CO2, and SO4) that bake out of the sample at each temperature increment. Many mineral species, including clays, sulfates, and carbonates, have diagnostic temperatures at which the volatile compounds are baked away. This EGA analysis will directly complement other chemical (e.g., APXS, ChemCam) and mineralogical (e.g., CheMin) analyses of the Stoer sample, and will be extremely important in understanding how the composition of this sample compares to others along the rover's traverse.

Before these SAM EGA activities, however, there is enough spare power for the science team to conduct approximately one hour of targeted remote science. The activities added to this science block include several Mastcam images to monitor changes in small ripple patches near the rover, imaging of the rover deck to monitor the accumulation of wind-blown sand and dust, and multispectral images of two targets. The first multispectral imaging target is named "Pentland Hills," which is a patch of broken rocks that was run over by Curiosity (within the wheel tracks of the displayed Navcam image. The second multispectral target is named "Strontian," which is an exposure of grey rocks in front of the rover. In addition to a few minutes of environmental analyses (including a dust devil survey), the bulk of the science block will be dedicated to a ChemCam passive observation calibration sequence. This sequence will ensure that ChemCam passive spectra can be accurately calibrated even as the martian dust storm continues to evolve over time.

Once these science activities are completed (by approximately local noon), Curiosity will spend the majority of the afternoon napping and saving power before the SAM EGA analyses run overnight from just before 11pm until just after 5am. After a mid-morning nap, Curiosity will be ready to go to perform additional science activities in tomorrow's plan!

Unlike normal weekend plans for Curiosity that encompass three martian days, this plan only covers two. This "Soliday Sunday" isn't really a day off for the rover like it implies, but instead allows the planning schedule on Earth and Mars to get back in sync. On Monday, the team returns to regular planning but there's still some great science happening this weekend.

CheMin is continuing its analysis of the "Stoer" drill sample but it's not the only instrument interested in getting a piece of the latest drill target. SAM, Curiosity's mass spectrometer instrument, is going to receive a sample drop-off from the drill assembly in the weekend plan. However, the Evolved Gas Analysis (EGA) won't actually be planned until Monday. Evolved Gas Analysis is a powerful technique that allows SAM to reveal the chemical makeup of the sample. In an EGA, the sample is heated and the materials that decompose or desorb (the opposite of adsorbing) at a specific temperature are measured in a mass spectrometer.

Targeted remote sensing on a suite of samples in the workspace continues to help us better understand the context of the drill hole. Environmental monitoring to track the waning dust storm and change detection on the drill hole tailings will also be carried out.

The planning day began with an interesting result from the previous plan's ChemCam RMI analysis of a target that was referred to as "Pettegrove Point Foreign Object Debris" (PPFOD), and speculated to be a piece of spacecraft debris. In fact it was found to be a very thin flake of rock, so we can all rest easy tonight - Curiosity has not begun to shed its skin! Perhaps the target should have been given a different name befitting the theme of the current quadrangle in which Curiosity resides: "Rabhadh Ceàrr", or "False Alarm" in Scottish Gaelic.

While indications of mechanical success from the previous plan's CheMin analysis of the drill sample at the "Stoer" target were received, the data will not be down until late this evening, so the drill campaign is taking a small hiatus to do some remote observations in this two-sol plan.

Environmental monitoring of the dust opacity or "tau" in Gale crater continues with multiple observations planned on each sol to observe diurnal variations, as well as the day-to-day trends as the global dust storm declines (as seen in the Navcam image below, the crater is still quite dusty!). Additional cloud monitoring observations and a dust devil survey are also included.

ChemCam will be taking the remote sensing to another level with its laser (LIBS) on targets "Balnakeil," "Ben Arkle," "Traboyack," and "Strontian 2" in the late morning of sol 2143, and "Loch Ranza" and "Strathconon" in the late morning of 2144. Following the ChemCam activities, Mastcam will provide additional change detection monitoring of the LIBS targets, as well as targets "Belhelvie," "Camas_Mor," "Sandray," and the drill tailings of the "Stoer" drill target. These observations will take place on both sols to observe the effect of the wind on the tailings and regolith.

Once the SAM team receives the preliminary results of the CheMin analysis, they will decide whether or not to request a SAM drop-off in the weekend plan, to prepare the drill sample for baking in an oven for what's known as an "evolved gas analysis" (EGA).

In today's plan, Curiosity begins analysis of the long-awaited Pettegrove Point drill sample at the "Stoer" target, which was successfully collected last week (and I had the pleasure of helping to sequence as a Rover Planner). Our main activity is the drop-off of sample to CheMin, based on the characterization of the drop-off portion size done in the weekend plan. There is still a good bit of wind, so the drop-off is around noon, during the calmest time. Overnight, CheMin will be busy analyzing the sample; we'll have the results down late Wednesday, which can then inform decisions about dropping off sample to SAM as early as this weekend's plan for analysis early next week.

On both sols of the plan, we're continuing our atmospheric observations to monitor the dust storm as it continues to abate, with dust devil surveys, and zenith and horizon opacity imaging. We'll be collecting additional ChemCam and Mastcam images of the drill hole, to look for vertical variability, and of the tailings, for change detection. ChemCam is also focused on mapping the bedrock variability by looking at several targets at various distances from the drill hole: "Pitlochry," "Ben Lui," and "Caltron Hill." Mastcam will be taking supporting documentation and additional change detection images on targets "Belhelvie," "Camas Mor," and "Sandray".

On our third attempt at drilling within the Pettegrove Point member on the Vera Rubin Ridge, we have success! Curiosity has successfully drilled, and generated a pile of drill tailings.

This weekend's plan is focused on the Stoer drill hole, the tailings derived from the drill and on portion characterization observations. The portion characterization is done prior to sending samples to the analytical instruments, SAM and CheMin, to ensure that the materials will not pose any threat to the instruments. ChemCam passive and Mastcam multispectral imaging will be taken of the drill tailings, to identify any potential differences between the surface and material from deeper within the drill hole. The ChemCam laser (LIBS) will be used to characterize the Stoer drill hole and a bedrock target "Greian," which appears to show some colour variations. Mastcam will provide colour documentation for Greian.

There will also be Mastcam change detection on the drill tailings (to identify if there is any movement of the drill tailings) and continuing change detection on three targets ("Camas Mor," "Belhelvie" and "Sandray"). Environmental measurements will be made to search for both cloud motion and dust devils.

After two sols of analyzing our intended drill site in the Pettegrove Point member, we began plans to drill the target "Stoer." Stoer has had Mastcam images, MAHLI images, APXS, and ChemCam observations acquired over the past two sols. The two previous drill attempts in this geologic member have not been able to get to successful depth since the rocks have been more resistant than what we saw earlier in the mission. Pettegrove Point is an important area to get a drill sample from because it is categorized as lower Vera Rubin Ridge. Curiosity has previously visited this area of Pettegrove Point on Sol 2097. On that sol we had a target "Caithness" which is close to our intended drill hole, Stoer. This is the last drill attempt in Pettegrove Point.

Besides drilling Stoer, we have four other targets planned for these two sols. We have planned for one ChemCam target named "Glen Brittle," and three Mastcam targets named "Belhelvie," "Camas Mor," and "Sandray."

Today I was ChemCam science downlink lead. This role processes data from previous sols and makes preliminary reports on ChemCam targets. Today was a slow day because data is currently backlogged. The downlink data is slowly trickling in, but uplink operations have not been slowed down. We still have enough information from the rover's current location to send commands to the rover. Hopefully we can get all of the backlogged data soon and get caught up again.