It has been a frustrating week for the Curiosity science and engineering teams. While we have a better understanding of how to recover the minor Remote Sensing Mast (RSM) issue that we encountered at the beginning of last week, we’ll need to try again before we can drive away. We are hopeful and quietly confident that perseverance will pay off and that we gain back full use of the RSM in this plan. Although our weekend remote sensing activities did not execute, Curiosity collected more compositional and close-up imaging data of these interesting, resistant capping rocks with APXS and MAHLI. The APXS also analyzed the atmosphere, looking for seasonal changes in the Ar concentration, as well looking at its calibration target.

Because of the continued RSM problems we focused on recovering as many of the mast activities as possible during this single sol plan before hopefully driving away. ChemCam will analyze the chemistry of the “Cleveland” bedrock target. We will document the previous CCAM/APXS targets; “Braco,” “Burn Mouth,” “Donkey Trail,” and “Venlaw” targets with Mastcam. Mastcam will also image a block that Curiosity appears to have driven over and broken, “Bowder Stone” to look for fresh surfaces and textures. Further afield, we will acquire a ChemCam RMI mosaics of the Gediz Valles ridge and Mastcam mosaics of ridges on the pediment, and the resistant rounded exposure, “Hartle Loup,” that we are currently investigating.

The environmental scientists planned several observations to continue monitoring changes in atmospheric conditions. These included: a Navcam dust devil survey, dust devil movie, a line of sight image and a sky flats observation; and a Mastcam basic tau observation. After our hopefully successful drive, we will image the terrain beneath the rover wheels with MARDI. Standard REMS, DAN and RAD activities round out this plan.

Curiosity’s stationary week on Mars continued because we weren’t able to uplink Wednesday’s plan. Fortunately, we are prepared for events like these. Our intrepid rover spent Thursday and Friday in “runout sols,” a term that describes the extra sols that are mostly empty of activity which we add to the end of every plan just in case we aren’t able to uplink new instructions.

Since we’d already discussed the observations we’d like to get at this location, the science team was in pretty good shape coming into planning this morning. Even though we want to simply repeat most of the activities we had planned to do on Wednesday, we still need to make a whole new plan because the orbiters we use to relay our data pass overhead at different times, and we’re also coming into the plan at a different state of charge than we planned on Wednesday. And of course - we have a three sol plan to make today instead of the two sol plan we made on Wednesday!

For our re-do plan, we’re going to try again to take a ChemCam observation of targets “Baa” and “Lewisian” described in Wednesday’s blog, as well as a new target “Cleveland,” which is a spot on a nearby rock that has interesting sedimentary structures. We’ll also snap some RMI mosaics of Gediz Vallis Ridge and collect Mastcam observation of the ChemCam targets along with the same mosaics we’d planned for Wednesday. MAHLI and APXS will get in on the science action with observations of “Blue Anchor,” and an additional MAHLI observation of “Baa.” (A “rinse and repeat” of what was planned Wednesday in the words of today’s APXS strategic planner Lucy Thompson.) Environmental monitoring and a drive round out the plan.

The rover engineers better understand the minor issue that occurred after our weekend activities. While we’re still in the same location, they can fix the issue in this plan. Our arm activities in the previous plan executed successfully. Today we focused on recovering the mast activities, as well as getting bonus, additional contact science at this location before driving.

The pediment capping rocks that we are currently investigating have revealed fascinating and varied textures and chemistry, which the team is busy trying to interpret. To that end, we certainly will not complain about getting more data here. The APXS and MAHLI instruments will both investigate the “Blue Anchor” target for chemistry and close-up textures respectively, and MAHLI will also look at the “Baa” target. Both these targets occur along an apparent contact between two layers and contain white grains in the darker grey matrix (seen in Mastcam images). We are testing hypotheses as to the origin of the white grains. To complement the APXS chemistry on the Blue Anchor target, ChemCam will analyze the similar looking “Lewisian” target, and the “Braco” target. We will document the Lewisian and Braco targets, as well as the previous “Burn Mouth,” “Donkey Trail” and “Venlaw” targets with Mastcam. Mastcam will also image a block that Curiosity appears to have driven over and broken, “Bowder Stone” to look for fresh surfaces and textures. Further afield, we will acquire a ChemCam RMI mosaic of the Gediz Valles ridge and Mastcam mosaics of ridges on the pediment, and the resistant rounded exposure, “Hartle Loup,” that we are currently investigating.

The environmental scientists planned several observations to continue monitoring changes in atmospheric conditions. These included: a Navcam dust devil survey, dust devil movie and line of sight image; a ChemCam passive sky observation; and a Mastcam basic tau observation. After our hopefully successful drive, we will image the terrain beneath the rover wheels with MARDI. Standard REMS, DAN and RAD activities round out this plan.

Unfortunately, our weekend drive stalled, so this morning we found ourselves still at Friday’s workspace. Fortunately, it was an understood issue... and this was a good place to spend some extra time and fill our science glass with amazing data! This workspace (“Hartle Loup”) has examples of different textures, bands of “vuggy” (the little holes or pits that you can see in the above image) material and smoother material. On Friday, APXS and MAHLI had to make some hard choices between all our desired targets, and we opted to characterize some “vuggy” targets but were unable to also get the “smooth” targets.

So, in a sense, the drive stall worked in our favour, allowing us to get three “smooth” targets here. APXS and MAHLI will investigate “Broadfell” and a brushed target “Venlaw,” whilst ChemCam will use LIBS to target “Cleveland”. Mastcam will take multispectral imagery (a further tool to help understand composition, often used for brushed targets) of Venlaw and were able to add a bonus multispectral image of the weekend DRT target (“Donkey Trail”) which we didn’t have time for on Friday. MAHLI took the opportunity to slip in a six image mosaic (series of overlapping images) looking at the interaction between the two textures. ChemCam will also examine “Bowder Stone,” a bedrock target that was broken up by the wheels last week.

Mastcam has, as always, a very busy plan. They will document the ChemCam targets from this plan, recover an image from the weekend on “Burn Mouth” which didn’t complete and get some more images of the pediment landscape. Mastcam will also aid the environmental group (ENV) in monitoring dust concentrations in the air, obtaining a crater rim extinction observation and a basic “tau” measurement, both of which are used to determine how much dust is the atmosphere.

Once we finish getting all this lovely bonus science at Hartle Loup, we will continue on our way, following the same drive path as we had planned to take over the weekend.

I learned a new word today: vug. Vugs are small cavities or pits on a rock surface and the rock in our workspace today was noticeably “vuggy.” Particularly, the triangular rock face in the bottom center portion of this Navcam image. This vuggy rock in the “Hartle Loup” outcrop seemed particularly unique relative to the other rocks on the Greenheugh Pediment that we’ve seen to-date. We chose this triangular rock face as one of our two contact science targets today (termed “Burn Mouth”) and the flatter rock face to its right as a second contact science target with DRT (termed “Donkey Trail”). ChemCam will also use LIBS on both targets.

In addition to the contact science, we continued this week’s effort to image as much of the Greenheugh Pediment and Gediz Vallis Ridge as we can from this location with Mastcam and ChemCam RMI. We will likely never have this perspective on this portion of those features, so we’re being very thorough with our imaging. ENV will use ChemCam to study atmospheric dust, ice, and gas abundances as well as take a series of dust devil movies, cloud movies, and measurements of atmospheric opacity.

No, Silly Place hasn’t become a new place name, but I totally agree with Ryan, who was yesterday’s blogger, that this is not our usual terrain. Would I want to go for a hike there, if I could? Sure, but very carefully, because this isn’t a place to risk a fall. Too many pointy rocks, so, silly place certainly fits. The MAHLI image above is probably somewhere in the pile of rocks you saw under the turret in yesterday’s image. From up close, you can admire the nature of those rocks: broken up with sharp edges. The eagle-eyed geologists amongst you might think they look like ventifacts, my fellow blogger Mark had mentioned those already in his sol 3419-3420 blog. Ventifacts are rocks, shaped by wind coming from the same direction(s) for a very long time. The wind carries fine particles that cause the abrasion to shape those rocks. But, as we all know, looks can always deceive at first glance. So, to get behind what actually happened here, and especially why it happened in some ridges that give the gator-back impression, Curiosity is taking many more images today and of course adding some chemistry to the mix, too!

APXS investigates the target “Breakyneck,” which is one of those sharp and angular rocks, and “Redscarhead,” which is a smoother looking and more flat rock that looks different, more like the bedrock we saw earlier. ChemCam has two chemistry investigations, pointing LIBS at “Breakyneck” and at another pointy, sharp-edged rock called “Swinton.”

Mastcam takes a record seeking 132 frames divided into four observations. Of course, always faithful to ChemCam, there are two images to document each of the LIBS targets. And then there is a large 69 frame mosaic on what was dubbed a gator back – more geologically speaking it is a ridge made of ventifacted rocks. The remaining 61 frames are looking at the landscape behind the ridge in front of us to find out how the washboard impression we have from orbit links to the ground observations. ChemCam has two imaging observations, too, both of them looking into the distance at the big outcrop on the other side of the plateau to find out more about the many sedimentary structures visible in this area. Finally, Mastcam also pleases the mineralogists and takes a multispectral image on the target “Calder,” which is yesterday’s APXS target.

The next drive is short to an area we have seen more rock textures, and where we hope to find out a lot more about this interesting area. Stand by for more images of sharp, pointy, laminated, and otherwise interesting rocks.

The original plan for today was to do a short drive to get within reach of some interesting new rocks. But after studying all of the images from our current location, the team realized that we can already reach some very similar rocks. By staying in one place, we were able to get a lot more science out of the day’s plan while reducing the risk of driving and ending up tilted in a position where we would not be able to use the arm.

The plan begins with a ChemCam observation of the bedrock target “Dollar” followed by a couple of long-distance ChemCam image mosaics of Gediz Vallis ridge. Then we have a Mastcam stereo mosaic of some of the interesting ridges in the middle distance plus some additional images of the “gatorback” terrain and a documentation image of Dollar. The morning science block then concludes with a Navcam movie to watch for dust devils.

The afternoon and evening are all about using the rover’s arm, with a whopping 4 contact science targets in the plan! After brushing the target “Calder,” we’ll take MAHLI pictures of it and of the other targets: “Scandal Beck,” which was yesterday’s ChemCam target, “Ashkirk,” and “Breakyneck.” In the evening, APXS will measure the chemistry of Ashkirk and Calder. Finally, in the morning of Sol 3423, Mastcam will take a 360-degree left-eye mosaic of our surroundings.

Not bad for a day's work! Sometimes it's better to take a closer look at what's around you, rather than rushing to somewhere new.

Curiosity is investigating the different surface expressions of the Greenheugh pediment, and the weekend drive put the rover right next to some “gator-back terrain” – some evenly spaced ridges with a blocky expression, as seen in the above Navcam image. Today’s one sol plan is focused on a close encounter with one of these ridges through contact science and remote sensing.

The plans starts with a ChemCam LIBS observation of “Scandal Beck” to assess the chemistry of the blocky outcrop. Then we’ll acquire 2 long-distance RMI mosaics to investigate the stratigraphy exposed in Gediz Vallis ridge. Afterwards, Mastcam will take two large mosaics to look at the sedimentary structures exposed in the “gator-back” ridge and characterize the erosion of these blocks. The rover will also take a Navcam dust devil survey now that we’ve entered the dusty season on Mars. In the afternoon, MAHLI will take a closer look at the grain size of these rocks at the target “Calder,” followed by an overnight APXS integration to learn about its chemistry. Early the next morning Mastcam will acquire a mosaic of Gediz Vallis ridge to document this feature from our good vantage point and morning lighting conditions.

Prior to arriving on the Greenheugh pediment, the team had been intrigued by the “washboard texture” preserved on its surface, as identified in orbital images. Now that we’re here it’s quite surprising to see how rugged it is, and the informal description of this “gator-back terrain” seems very fitting!

After a ~15 meter drive to the west along the top of the Greenheugh Pediment, Curiosity is now positioned at an interesting textural transition within the pediment’s surface units. Quite a large amount of the pediment is dominated by a washboard-like pattern at the surface that can be easily observed from orbit, while the region Curiosity ascended onto the pediment surface is rugged yet lacks those clear washboard-like features. With this latest drive, Curiosity is now positioned at the transition between these two surface units, and the team is continuing to assess the traversability of this units.

With this new vantage point, the plan is for Curiosity to spend the weekend characterizing the different morphological features observed on top of the pediment. The weekend plan will start with several Mastcam imaging sequences designed to characterize the washboarding that is observed in the landscape ahead of the rover. The terrain’s small-scale roughness and oriented ventifacted rocks led the Science Team to informally refer to these textures as “gator-back terrain” (see image). Curiosity will also perform two ChemCam LIBS analyses on two different targets - a smooth outcrop target named “Macmerry” and a rougher knobby target named “Ochiltree.” After a ChemCam passive sky observation around midday on sol 3419, Curiosity will unstow her arm to conduct an APXS integration on the outcrop target named “Blackadder” and an overnight APXS measurement to characterize the martian atmosphere. Finally, on the sol 3420, Curiosity will complete her Mastcam and ChemCam observations (including a long-distance remote imaging mosaic) before embarking on a planned ~35 meter drive to the west to continue the investigation of the pediment and the interesting surface textures found on its surface.

Our Monday drive was successful, and we are now fully surrounded by the rocks that cap the Greenheugh pediment. From here we can see hundreds of ventifacts – a term that describes rocks which have been abraded by wind-blown sand into distinctive, flattened facets with crisp edges. This terrain is very different from what we’ve become used to seeing during our climb up Mt. Sharp!

Today’s plan is all about exploring the local area. We will collect APXS and MAHLI observations of a relatively large, less dusty ventifact near the rover’s wheel at a target named “Knott.” Elsewhere on that same rock, we will also collect a ChemCam LIBS observation of a target with neat sedimentary structures named “Old Nab,” as well as a ChemCam RMI observation of another area of the rock named “Little Mell.” This rock is visible in the upper left in the above Navcam image. We’ll also collect several Mastcam mosaics of targets near and far, as well as a standard set of observations to monitor our environment. The first day of the plan concludes with a drive to the southwest, towards a very small crater that might give us an interesting glimpse into the sedimentary structures in the area.

At our perch on the top of the pediment, we have a spectacular view of the terrain below. We can see across the plains of Gale crater where we landed all the way to the crater’s rim tens of miles in the distance. Slightly closer, we can also see the distinctly layered nature of Gediz Vallis Ridge, which sits on top of the pediment and is one of the youngest geomorphic features on Mt. Sharp (seen to the left in this image). Between the ventifacts and the viewshed, it’s quite an imposing place to rest before our next drive.