Heedless of the (now-dissipating) dust storm, Curiosity has achieved its first successful drill into rocks that form the Vera Rubin ridge, and is hopefully on the way to a second. It took three attempts for Curiosity to find a soft enough spot, with Voyageurs and Ailsa Craig being too tough, but Stoer proved obligingly soft on sol 2136. The rover delivered samples to both of its analytical laboratory instruments before driving away.
There have been lots and lots of images landing on Earth in the last several weeks, as Curiosity is ramping up data relay through MAVEN and ExoMars Trace Gas Orbiter. Once InSight lands, Curiosity will have to give up most of its Mars Reconnaissance Orbiter data relay to the lander -- InSight’s landing site is just a couple hundred kilometers north of Curiosity, so both missions want the same data relay passes as the polar-orbiting spacecraft passes overhead. For Curiosity, switching to MAVEN and ExoMars relay can replace the volume, but not the rhythmic repeatability, of Mars Reconnaissance Orbiter’s twice-a-day-like-clockwork relay sessions. Until InSight lands, though, Curiosity gets to hog all the data volume -- so the team is taking advantage of the bounty while it lasts.
Speaking of image bounty, I want to share this Mastcam self-portrait, taken at the Stoer drill site. Curiosity acquires most of its self-portraits with the MAHLI camera on the end of the arm, but the team is being cautious about using MAHLI much while the dust storm’s dust is still settling out of the sky. (More on this below.) Mission scientists wanted to document the accumulation of dust on the rover’s deck, so without MAHLI being available, that meant a Mastcam deck panorama. In Mastcam deck pans, we can see the arm but not the mast; the reverse is true in MAHLI self-portraits.
No Joy at Voyageurs or Ailsa Craig
Spirits were high on the team as the rover departed the successful drill site at Duluth on sol 2084. They were ready to do a real drill campaign across the ridge, sampling its rocks in at least three places. In order to get to Duluth, Curiosity had driven down the relatively steep northern face of Vera Rubin ridge, so the next task was to drive uphill again. There were a few stalled drives as the rover encountered challenges in the climb, but the wheels were back on top of the ridge as of sol 2098.
Ten sols later, the rover pulled up to a site named Voyageurs. Roger Wiens nicknamed it “The Great Red Spot” because on an orbital map showing hematite mineral abundance on the ridge, Voyageurs lay within the brightest red pixel. Here’s a look at that map of hematite abundance from Mars Reconnaissance Orbiter’s CRISM instrument, which I’ve overlaid with Curiosity’s course. Voyageurs is one of the brown dots.
Spectroscopist Abigail Fraeman was especially excited to reach Voyageurs, because her Ph.D. thesis focused (in part) on high-resolution mapping of hematite along the ridge. Full of anticipation, the team drilled, and...womp, womp. (For those of you unfamiliar, that is the Internet’s approved transcription of the “sad trombone” sound.)
The drill barely penetrated. After only 3.7 millimeters, forward progress stopped. No sample.
With their enthusiasm dampened, but not their determination, the team commanded the rover to drive away from the very brightest hematite signal to a spot they thought might have softer rocks. Ailsa Craig, attempted on sol 2122, wasn’t any softer; it achieved only a couple more millimeters of depth, and it still was not deep enough to get any sample into the drill (the drill has to penetrate at least 15 millimeters into the rock for that). They drove away two sols later.
The failed drill attempts weren’t entirely useless. Both resulted in small piles of freshly ground rock powder. The APXS and ChemCam teams are very happy to target such fresh surfaces for elemental chemistry analysis, because even a small amount of scraping penetrates beneath the surface coating of dust and weathering rind that can obscure rock composition.
Searching for softer rocks
Clearly, it would save a lot of effort (not to mention precious mission resources) if the team could figure out ahead of time which rocks are going to be drillable, and which aren’t. The question comes down to how hard the rock is.
Those of you who have taken an Earth science class have probably heard of the Mohs hardness scale for minerals, but Mohs is not the scale that’s used for rock hardness. Rocks are composed of mineral grains. Mohs hardness (measured from 1 to 10, with talc being softest and diamond being hardest) refers to how resistant those grains are to being scratched -- a harder mineral scratches a crystal of a softer mineral. But the Mohs scale doesn’t say anything about how resistant the grains are to being broken apart. A block of solid talc will support more weight, and be harder to drill into, than a pile of teeny diamonds held together with honey.
To talk about rock hardness, geologists refer to its compressive strength. Curiosity’s drill is a percussion drill, so what matters is how resistant its grains are to being powdered by its percussive hammering. What clues might the Curiosity team use to figure out whether a rock will have low enough compressive strength for drilling to work, other than actually trying to drill it?
One possible clue comes from the rover’s brush, which has steel bristles. When the rover brushes a rock -- as it does almost every time it puts the APXS compositional instrument on a rock target -- the steel bristles of the brush sometimes scratch the rock surface. If the brush scratches the surface, the rock is probably on the soft side and an easy drill target. However, not scratching doesn’t necessarily mean it’s not drillable. And of course this scratch test requires the rover to actually reach out and touch its arm to a rock, which is costly in terms of mission time and resources.
One clue that Curiosity can see from a distance is veins. Veins are everywhere in Gale’s rocks. Most of the time, erosion leaves veins standing out from the rock surface, indicating that the rocks are less resistant to erosion than the veins. In some places on Vera Rubin ridge -- notably, at both Voyageurs and Ailsa Craig (see the photos above) -- the veins are places that are eroded into the rocks, indicating that the rocks are more resistant. So Curiosity needs to look for places where the veins stand out, or at least aren’t eroded away.
A third clue -- one that can even be spotted from orbit -- is in the geomorphology. You find harder rocks capping topography (which is why it’s no surprise the top of Vera Rubin ridge is made of especially hard rock; it's the highest topography around). If you see a break in slope -- a place where there is a steep scarp capping a shallow slope -- then you know that natural forces have had an easier time eroding the rock that makes the shallow slope than the rock that makes the steep scarp. So, all else being equal, the team might select drill targets in flatter rocks that they find at the toes of scarps.
Success at Stoer
The team had picked Voyageurs and Ailsa Craig based on orbital chemistry (the hematite signal). When that didn’t work out, they drove to a spot near where they had seen veins standing out and where they found a flattish place at the base of a scarp. It wasn't as bright a spot from orbit, but the measurements from ChemCam and APXS were "within the in situ-derived chemical family" of the Pettegrove Point rocks they were trying to sample -- good enough. Once they got there, they used the brush, and scratched the rock. Then they tried drilling a third time. That’s how they succeeded at Stoer.
Curiosity pulled up to Stoer on sol 2132, and achieved the full commanded drill depth, 46 millimeters (of a commanded 45) on sol 2136. Delivery to CheMin happened on sol 2141, and to SAM on sol 2147. SAM decided not to take a second sample, and they dumped and cleaned the drill on sol 2154 and drove away on sol 2156. Pretty quick work!
If you look at the hematite map at the top of this post, though, Stoer lies in rocks that look a bit more like Duluth than the ridge top rocks from orbit. Did Stoer have the chemistry what they wanted to find? Did the Curiosity team actually learn something about the rocks that made the strong hematite signal visible from space? Alas, I can’t tell you. My blog updates focus on operational details because that’s what the mission shares in real time. Science takes longer, because it takes time to reduce data and place it into context and it’s normal for scientists to reach the wrong conclusions before they reach the right ones (or, at least less wrong ones). Scientists do their best not to share the likely-to-be-wrong early speculations publicly. I’m eagerly awaiting the first scientific presentations on the drilling campaign across Vera Rubin ridge.
If you’re keeping score at home, you might notice the commanded drill depths are decreasing over time. Before the feed anomaly, they routinely drilled to 65 millimeters. At Duluth, they commanded 50 millimeters. At Stoer, it was 45. I wouldn’t be surprised to see the next drill site commanded to a depth of only 40. They’re drilling less deep just to save wear on the drill, especially the percussion mechanism. Once the drill has penetrated into the ground to a depth of 20 millimeters, any further drilling won’t get more material to deliver to the instruments, it just contributes to the size of the eventual dump pile. They do want to have some material available to make a dump pile. The dump pile is what they analyze with the chemistry instruments, APXS and ChemCam. So they’ll always drill to whatever depth past 20 gets them a satisfactory dump pile.
The next drill site will be a spot where they can compare and contrast the “blue” and “red” rock types of the upper ridge (see this earlier Vera Rubin ridge post for some discussion of what those color names mean).
Dust storm and camera caution
The dust storm kept skies pretty opaque for most of the period covered in this update. At Voyageurs, there were still no visible shadows, a sign of enough dust to make the sky appear overcast.
The MAHLI team is especially concerned about protecting their instrument from the settling dust. MAHLI has a dust cover, so it’s actually more protected than the other cameras -- so why the concern? It’s because MAHLI is designed to focus on objects very close to the lens. For the far-viewing Mastcams, a speck of dust on the lens is so out of focus that it just makes a diffuse dark spot that is easy to correct in software. From time to time, the camera team takes photos of the sky as flat fields to help with these corrections. If a speck of dust were to land on MAHLI’s optics, it would be much closer to being in focus than the same speck of dust that landed on Mastcam. A speck of dust on MAHLI would actually occlude the view, and would not be correctable with a flat field. Obviously the team would like to avoid that if at all possible.
MAHLI does have a transparent dust cover, and it has sometimes worked to do MAHLI imaging with the dust cover in place. The dust cover is very, very dusty now. The dust on the dust cover doesn’t affect MAHLI’s ability to focus, but it does affect the contrast in MAHLI images. The lack of contrast can usually be fixed with image processing, but the dust storm is causing problems here, too. The overcast skies and lack of shadows causes a lack of contrast in the landscape. That, in turn, means that images shot through MAHLI’s dust-coated dust cover are essentially useless. This, believe it or not, should be a typical wheel survey image. If you stare hard, you can just barely make out the sharp line of the belly of the rover contrasting with the Martian sky at upper left.
The team has developed a new way of doing wheel imaging while dust settling on the MAHLI optics is a concern. Routine wheel imaging has always included photos of the right-side wheels with the Mastcam. (For examples, see this one and the four images following it.) For now, the Mastcam will take the only pictures of those wheels; none will come from MAHLI. But because the mast is mounted on Curiosity’s right shoulder, it can’t see the left-side wheels at all. The new MAHLI sequence has MAHLI looking nearly straight down at Curiosity’s left-front and left-middle wheel to observe their condition. The MAHLI team feels safest about using MAHLI when it is pointed straight down, a geometry in which dust is unlikely to settle on its optics. MAHLI won’t be able to see the left-rear wheel, but both rear wheels are in excellent condition and don’t need such frequent monitoring.
Sam inlet view
Finally, a fun little animation showing a part of the rover that I've never seen before: the open SAM inlet cover. Curiosity has three inlets on the deck for the instruments to accept samples: two for the SAM instrument (the gas chromatograph mass spectrometer and other stuff, which focuses on organics and atmospheric composition and lighter elements like hydrogen and carbon) and one for the CheMin instrument (which does x-ray diffraction/x-ray fluorescence to identify minerals). CheMin is protected by a screen, which MAHLI routinely images to make sure nothing is clogging the screen. But SAM doesn't want MAHLI poised over its inlet for reasons to do with avoiding cross-contamination, so MAHLI has never taken an image of the SAM inlet. Now that the team has switched to a different way of delivering sample, they wanted to check around the SAM inlet to make sure that samples being dropped from the drill weren't falling outside the inlet funnel. So they used Mastcam to take a photo of it for the first time. It feels almost indecent -- this is an exposed part of Curiosity I'd never seen before!
That’s it, until next time. Hopefully next time I’ll have two more drill sites to tell you about! For now, please enjoy more than 10,000 words of detailed updates written by Curiosity team members, reposted from here.
Curiosity Mission Updates
Sols 2093-2094 update by Lauren Edgar: Feeling powerful (26 July 2018)
Today’s 2-sol plan kicked off with the good news that our power state exceeded predictions, so we were able to add in some extra science activities. The first sol starts with several remote sensing activities to continue to monitor the ongoing dust storm. Then the team planned several ChemCam observations of “Mudhole Lake,” “Jacobs Lake,” and “Monker Lake” to assess the bedrock chemistry and search for evaporites, followed by Mastcam documentation. In the afternoon, Curiosity will acquire a short multispectral tau observation to measure the optical depth of the atmosphere and constrain aerosol scattering properties. Given the extra power today, but without many appealing contact science targets, the team decided to get an APXS calibration target observation overnight. On the second sol Curiosity will continue driving up the steep slope to the south, followed by post-drive imaging and further atmospheric observations. I’ll be on duty for the next plan, so I spent today getting caught up on everything that Curiosity has been up to!
Sols 2095-2096 update by Lauren Edgar: Over the crest (28 June 2018)
After a steep drive Sol 2094, Curiosity is back over the crest of Vera Rubin Ridge and enjoying the view of flatter terrain ahead. I was the SOWG Chair on this late slide sol, which means that we started planning 3.5 hours later than usual. Everything was going smoothly and we were excited to plan some potential contact science, until we found a rock under the left front wheel that might make Curiosity unstable during arm activities. So at the last minute we swapped out MAHLI and APXS activities for some additional remote sensing. We still packed a lot of science into the two-sol plan, and we’ll have another opportunity to do contact science in the weekend plan.
The first sol includes ChemCam and Mastcam observations of “Crosby” and “Hekkla Lake” to characterize the bedrock at this location. This plan is also full of atmospheric observations to monitor the ongoing dust storm, which will provide some great data from the surface regarding this unique event. We also planned Mastcam imaging of the rover deck to monitor the accumulation and movement of fine material, as well as a number of ChemCam calibration activities under high atmospheric opacity conditions. Then Curiosity will continue driving to the south and will acquire post-drive imaging to prepare for the weekend plan. Overnight, CheMin will carry out the last analysis of the Duluth drill sample. The second sol includes more atmospheric monitoring and calibration activities, along with a ChemCam AEGIS observation to autonomously target bedrock in our new location. Hoping for clearer skies and fewer loose rocks under our wheels!
Sols 2097-2099 update by Christopher Edwards: Stopped Drive (2 July 2018)
Curiosity stopped its drive a bit earlier than anticipated. It so happens that the autonomous software onboard Curiosity designed to keep it driving safely kicked in and ended the drive short of the planned distance. When things like this happen, it’s a bit of a setback to science, but keeping the rover safe is priority number one. Not only did the drive stop short, but Curiosity actually ended up in a location where there wasn’t a good surface model, triggering the Slip Risk Assessment Process (SRAP) to fail. A failed SRAP means that Curiosity cannot safely carryout any arm-based activities, so the science team resorted to remote sensing activities using the cameras and ChemCam to continue to assess the Vera Rubin Ridge.
In this three sol plan, Curiosity will first carry out a host of remote sensing activities including 5 ChemCam activities, Mastcam documentation images of the ChemCam locations and a small Mastcam mosaic of a layered rock outcrop on the horizon. On the second sol, the rover will make good progress driving along the previously planned path using only the existing terrain surface model that is available. The usual suite of post-drive imaging to help decide science targets in the next plan will also be acquired. Importantly, as the dust storm on Mars continues to affect Curiosity, activities designed to monitor the amount of dust in the atmosphere will remain a priority and be made as frequently as possible.
Sol 2100-2101 update by Scott Guzewich: Back on Top (2 July 2018)
Curiosity is back on top of the Vera Rubin Ridge once more, having completed our drive over the weekend as we move toward our next drilling target in the “Pettegrove Point” geological member. This Navcam image shows the occasionally steep edge of the Vera Rubin Ridge on the left side of the image and the dusty haze beyond it that has shrunk our horizons for the last few weeks.
Today’s 2-sol plan involved contact science with APXS on rock targets “Dumbarton Rock”, “Duntarvie Castle”, and “Duntelchaig” and four ChemCam LIBS rasters on nearby targets. After climbing back onto the ridge, there is no lack of interesting bedrock targets nearby and the ground is much smoother and suitable for driving compared to where we’ve been for the last many weeks while we studied our “Duluth” drill hole and its surroundings.
As ENV science lead today, I continued our dust storm campaign with a variety of measurements of atmospheric dust opacity (which has continued a very slow decline from a peak about 2 weeks ago). We’ve had to alter existing measurement techniques for measuring dust opacity and create new ones to account for the high amounts of dust in the atmosphere and the corresponding low light levels at the surface. But this also affords us new opportunities to study the properties of dust particles themselves.
Sols 2102-2103 update by Mark Salvatore: A Working Holiday (4 July 2018)
While the rest of us are enjoying fireworks, BBQs, and spending time with friends and family, Curiosity will remain hard at work over this Fourth of July holiday. On Monday, the science team planned Monday and Tuesday activities on Mars, while today (Tuesday) they planned Wednesday and Thursday activities. This will allow the rover team to take a well-deserved holiday break on Wednesday!
Because of this interesting planning timeline, however, the science team had to make today’s plan before Curiosity executed the plan that was created yesterday. This is no problem though, as we’re in the same location, so we have plenty of activities to do and know which targets to focus on.
In yesterday’s plan, Curiosity used her arm to acquire Alpha Particle X-Ray Spectrometer (APXS) measurements on three targets - one brushed with the Dust Removal Tool (DRT) and two unbrushed targets. Today’s plan will use the arm to acquire high-resolution images of these three targets (named “Dumbarton Rock,” “Duntarvie Castle,” and “Duntelchaig”) using the Mars Hand Lens Imager (MAHLI). There was quite a bit of discussion about how much time the MAHLI and other images acquired by Curiosity would take in the middle of this dust storm, now that the sky is much darker than usual and the illumination conditions are very different from the typically clearer skies that Curiosity has been used to for the past several years. In the end, it was determined that imaging would not be significantly influenced by the darker and dustier skies. A ChemCam LIBS analysis was also planned on the “Callanish” target, which is a layered block just off the right front wheel of the rover. This observation will help in our continued documentation of the chemical variations observed as we climb back up the Vera Rubin Ridge.
Following these operations, Curiosity will tuck her arm back into its stored position and continue her drive up the ridge. During her drive, Curiosity will acquire frequent images of the ground using the Mars Descent Imager (MARDI). This imaging sequence is referred to as a “sidewalk video,” as the final stitched mosaic looks like sidewalk blocks moving across the martian landscape. These sequences help us to see how the terrain under the rover changes as we progress across the surface. After her drive, Curiosity will undertake a standard post-drive imaging campaign to characterize the surrounding landscape, which can be used by the rover team to plan subsequent scientific and navigational activities. On the second day of the plan, Curiosity will obtain automated chemistry measurements using the ChemCam LIBS instrument. These data will be sent down to the rover team before the next planning session.
Sol 2104-06 update by Scott Guzewich: Have we reached the peak? (26 July 2018)
Our primary goal for today’s planning was to continue to approach our next drill location on the Vera Rubin Ridge by paralleling the north side of the ridge (seen on the left side of this image) during this plan’s drive while documenting the geochemistry of the bedrock we’re currently parked on and continuing to study the ongoing planet-encircling dust storm. A warning from ChemCam received early this morning prevented us from employing ChemCam for both of those purposes, but it was cleared up later and will be ready for Monday’s planning. We therefore took advantage of the unexpected availability of science time to include some routine Mastcam calibration activities and additional observations of the dust storm.
The amount of dust over Gale Crater has been slowly declining over the last two weeks and it’s possible the dust storm has reached its “peak”. Whereas on Earth we have thousands of surface weather stations and a constellation of spacecraft observing the weather, on Mars we are comparatively blind to global conditions. But based on what data we do have, we may now be entering (or soon entering) the period where the massive amount of dust in the atmosphere will slowly settle out and Mars’ shrouded surface may once again be clearly visible from space.
Sol 2107 update by Roger Wiens: Heading Back to the Great Red Spot (9 July 2018)
The image above shows the Mastcam view as of Sol 2104, in which the nearby terrain is clearly visible, but nothing beyond the foreground, and the entire scene looks a murky red-brown color due to the dust storm. Unhampered by the storm, Curiosity is heading back toward a site visited on Sol 2005 for what we hope will be the next drill target. Jupiter is known for its “Great Red Spot”, which is a swirling storm thousands of kilometers in diameter. The rover drive destination could perhaps be called the “Great Red Spot on Mars” as it seems to indicate the presence of a reddish mineral, hematite, as seen from orbit and in rover spectra. Of course this spot is not at all as prominent from orbit as Jupiter’s Great Red Spot, but the orbital spectra do predict this location to have one of the highest surface hematite abundances in this part of Gale crater.
ChemCam was marked healthy over the weekend after repetition of a known event last week. REMS lost a small amount of science data over the weekend in a slight anomaly, but the instrument remains healthy.
Today we will uplink a one-sol plan. Activities will include a drive to cover most of the 50 meters remaining to our planned drill target. There are three targets in the pre-drive workspace. The arm will deploy MAHLI and APXS to target “Chippewa”. APXS will get two 15-minute integrations; MAHLI will image from 25 and 5 cm distances. ChemCam will target “Animikie” nearby. Mastcam will document that target plus “Barnum”, a piece of bedrock in between the other two. Navcam will continue checking the atmospheric opacity and Mastcam will collect a 4-image mosaic of “Taconite_crater.” DAN, REMS, and RAD will continue taking environmental data.
Tomorrow is a “soliday” or effectively a leap day in which Earth has an extra day relative to Mars. Our next sol of uplink will be on Wednesday.
Sol 2108 update by Roger Wiens: Back Towards Stranraer (11 July 2018)
After being out of commission for over a year, Curiosity’s drill is making not just a comeback, but a strong one, with imminent plans for a second drill hole within the span of 60 sols. The rover is heading back to a place it visited on Sol 2005, looking to drill near target Stranraer. Curiosity has just been climbing back up Vera Rubin Ridge from drill target Duluth, which was drilled on Sol 2057 at the base of the ridge. If the rover succeeds with another drill target within the next few sols, it will be quite a rapid turn-around. Previous instances when drill holes were made within rapid succession include the combination of Mojave and Telegraph Peak (sols 882 and 908) at Pahrump; the trio of Lubango, Okoruso, and Oudam on Naukluft Plateau between sols 1320 and 1361; and Quela and Sebina between sols 1464 and 1495.
Curiosity still has about six meters to go to the area around Stranraer, so the short drive will be a feature of today’s activities. Along with that, and still using target names from northern Minnesota, ChemCam will analyze targets “Fort_Francis and “Icarus_Lake”. APXS and MAHLI will analyze a dark rock named “Orr”. (A MAHLI image of nearby bedrock target “Dumbarton_Rock” is shown in the above image. Laser pits and crystal forms can be seen in the red rock.) After the drive, Navcam will take images of the region in front of the rover, and the onboard computer will select a new target for ChemCam to shoot. Mastcam will take an image for the clast survey, and will check the sky conditions with a tau measurement and a view out to the crater rim (if it shows up through the dusty air). RAD, REMS, and DAN will get data, including a DAN Active measurement, and MARDI will take an image of the ground beneath the rover.
Sol 2109 update by Abigail Fraeman: Voyageurs (12 July 2018)
I first became involved with Curiosity shortly after starting my third year of graduate school in the fall of 2011. My graduate advisor was selected to join the mission as a Participating Scientist, and he enlisted me to help analyze orbital data over Mt. Sharp as part of that role. In particular, I was tasked to examine data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to see what minerals Curiosity might find when she landed and, importantly, where exactly she should drive to visit the best exposures.
One of the most the significant things I found was the signature of the mineral hematite (Fe2O3) associated with the feature we now call Vera Rubin Ridge. Many collaborators and I spent the winter and spring of 2012 -- the time between launch and landing -- working out the geological implications of this discovery as best we could using orbital data, and beginning to ponder the specific observations Curiosity should make when she reached the ridge. I first presented these findings to the Curiosity science team on sol 15 of the mission (or August 20, 2012 Earth time).
Almost 2100 sols and countless exciting discoveries later, Curiosity is now poised to drill at the exact spot we first detected the strongest hematite signature over seven years ago. We’ve named the new drill target “Voyageurs” after a National Park in northern Minnesota. I love this name because it reminds me we truly are a team of voyagers, participating in a mission of exploration and discovery. The data we collect from this sample will help us better understand the environments that shaped Mt. Sharp over time, and, on a personal level, it will allow me to test some of the hypotheses I first started to formulate as a graduate student back in 2012.
Sol 2109 will be the first sol of our drilling campaign at Voyageurs (very close to the former target “Stranraer” that we examined back around sol 2004). The main focus of the sol’s plan will be contact science of the site, including DRT, MAHLI, and APXS observations. We’ll also take a Mastcam documentation of yesterday’s AEGIS target and do some ChemCam calibration activities. As always, we will continue to take environmental science observations to monitor the ongoing dust storm. As you can imagine, I am quite anxious and excited to see what we find!
Sols 2110-2112 update by Lauren Edgar: Let the drill fest begin! (13 July 2018)
Drilling on another planet is no easy feat, and each time we have the opportunity to do so on Mars feels pretty special. The focus of the weekend three-sol plan is to drill the target “Voyageurs,” which is part of an outcrop that shows a high hematite signature in orbital data.
The weekend plan kicks off with several Navcam and Mastcam observations of the atmosphere to continue to monitor the ongoing dust storm from our unique vantage point on the ground. Then ChemCam will analyze the “Voyageurs” target, followed by Mastcam multispectral imaging. Curiosity will continue several important environmental monitoring observations later in the afternoon and first thing the next morning, and throughout the second and third sols. The second sol also includes more Mastcam change detection observations of three different targets to look for changes and the movement of fine material. Then we’ll acquire MAHLI pre-drill images, and APXS on the future dump locations. With those observations complete, we’ll be “go” for the full drill of the “Voyageurs” target on Sol 2112! I’ll be on duty on Monday, so I’m anxiously awaiting the results of the drilling attempt and look forward to finding out what this rock is made of!
Sol 2113 update by Lauren Edgar: Hard as a rock (16 July 2018)
Unfortunately, we found out this morning that the “Voyageurs” drill target was a much harder rock than expected. While our drill plan executed perfectly, our bit stopped short of the full depth we need for sampling. The engineers are still evaluating the data to better understand the target. I had a busy morning as SOWG Chair, as the team had to come up with a new plan for today while thinking about our longer-term strategy. Ultimately, we decided to focus on contact science and documenting the mini drill hole in today’s plan.
The plan kicks off with several Navcam observations to monitor atmospheric opacity during the ongoing dust storm. Then we’ll take several Mastcam change detection observations to characterize the movement of sand, followed by several ChemCam observations to assess the diversity of color and composition in the bedrock here. We’ll also take a ChemCam RMI image of the “Voyageurs” target, which will help with targeting the drill hole with ChemCam in tomorrow’s plan. The afternoon includes a few more environmental monitoring activities, including a Navcam line-of-sight image, Mastcam tau, and crater rim extinction observation. Then Curiosity will image the drill chuck, drill bit, and turret, to monitor our tools. In the evening, we’ll acquire an APXS integration on the drill tailings, and overnight we’ll get a longer APXS integration on the drill hole. Today is a reminder that it’s hard to operate a rover and drill on another planet, but I’m hopeful that we’ll find a way to sample this part of the ridge!
Sol 2114 update by Mark Salvatore: Finishing Up at the Voyageurs Drill Site (17 July 2018)
After our attempt to drill the Voyageurs target did not reach sufficient depth due to the impressive hardness of the rock , the team is beginning to finish up its activities at this location before heading a bit further uphill to find a more suitable (i.e., softer) drill target. All evidence suggests that this rock target is one of the hardest yet observed in Gale crater, a property that may be indicative of this entire section of the Vera Rubin Ridge. To a geologist, variations in rock hardness could indicate several different physical and chemical properties about a rock. It is important for us to further characterize and understand why this rock unit is so much harder than the underlying rocks within the Murray formation. Could this increased hardness be related to changes in water chemistry as the sedimentary rocks were being deposited? Or, could this increased hardness be due to subsequent cementation as iron-rich water was injected into the previously deposited sedimentary rocks? In order to address these possible formation mechanisms (and countless others), we must continue to gather data on the physical, chemical, and mineralogical properties of this portion of the Vera Rubin Ridge.
Today’s rover activities contain a combination of scientific investigations and engineering activities. The plan starts with a short imaging science block around 11:30am local time, where Mastcam will be used to acquire images of the surrounding landscape to search for short-term changes to the surface, including sand migration and changes to dust cover. Navcam will also be used to investigate the atmospheric dust content and to search for nearby dust devils. Following this block of observations, Curiosity will use the Mars Hand Lens Imager (MAHLI) high-resolution camera to investigate the shallow Voyageurs drill hole and to image the rover wheels with its dust cover closed (to avoid dirtying the camera lens). After a short nap and a data uplink to the Mars Reconnaissance Orbiter as it passes overhead, Curiosity will embark on another block of science activities beginning around 3:00pm local time. This second suite will include Mastcam images of the dusty atmosphere, a ChemCam laser-induced breakdown spectroscopy (LIBS) chemical analysis of the Voyageurs drill hole, a LIBS measurements of the ChemCam calibration target, and a follow-up Mastcam documentation image of the drill hole. This will conclude the sol 2114 science activities.
I served as the geology science theme lead during yesterday’s plan, when the team first had to deal with the realization that the drill activities at the Voyageurs target did not penetrate deep enough into the target to acquire materials for analysis onboard the rover. While disappointing, the information gathered about the rock properties and drill activities led to a deluge of productive scientific discussions about how to proceed and what these observations tell us about the geologic environment that Curiosity is investigating. It’s moments like these that remind me of how lucky I am to be working with such an impressive group of scientists and engineers, who can collectively turn a frustrating sigh into a gasp of excitement as we think about our next observations and what more we have to learn about this interesting and foreign environment.
Sol 2115 update by Ken Herkenhoff: New method of wheel imaging (18 July 2018)
The priorities for Sol 2115 are to image the rover’s wheels and acquire the images needed to plan a drive back to the Sol 1999 location, where we might start another drilling campaign. The MAHLI images of the wheels taken on Sol 2114 with the dust cover closed show that there is enough dust on the cover to make it difficult to see the wheels, so a different approach to wheel imaging was planned for Sol 2115. To minimize the risk of dust contamination of MAHLI’s optics while the cover is open, MAHLI will image only the wheels on the left side of the rover from above the wheels, keeping MAHLI pointing downward while the dust cover is open. The wheels on the right side of the rover will be imaged by the left Mastcam rather than MAHLI. Then the rover will turn in place to allow imaging in the direction of the next drive, toward the southwest. After acquiring the standard post-drive data, Mastcam will observe the Sun and crater rim to continue the monitoring of the dust opacity over Gale Crater. These observations will be repeated twice early in the morning on Sol 2116 to look for short-term changes in opacity. In addition, ChemCam will use the AEGIS software to autonomously select a bedrock target for a 3x3 LIBS raster. Tactical planning went smoothly, so it was an easy day for me as SOWG Chair!
Sol 2116 update by Ken Herkenhoff: Driving back to Sgurr of Eigg (19 July 2018)
The Sol 2115 wheel imaging went well, and we received the images needed to plan a drive back to “Sgurr of Eigg,” near the Sol 1999 rover position. The >50-meter drive dominates the Sol 2116 plan, but leaves time for continued atmospheric and other scientific observations. Before the drive, Right Mastcam will image the ChemCam target selected by AEGIS on Sol 2115 and Navcam will monitor the opacity of the atmosphere. After the drive and the standard post-drive imaging needed to plan weekend activities, Mastcam will measure the atmospheric opacity and ChemCam will observe another target selected by AEGIS. Early in the morning of Sol 2117, Mastcam and Navcam will again monitor opacity, and Navcam will look for clouds overhead and near the horizon to measure wind velocity.
Earth and Mars are getting closer to each other this month, and by the end of this month Mars will be closer to Earth than it has been since 2003! Mars is visible low in the southeast after evening twilight. If you have a good telescope, you can monitor the progress of the global dust storm that is being intensely studied from spacecraft orbiting Mars as well as by MSL.
Sols 2117-2119 update by Michelle Minitti: “Ben” There (20 July 2018)
Curiosity made great progress yesterday across the “Vera Rubin Ridge” toward the site of our next drilling attempt at “Sgurr of Eigg”. In this weekend plan, we will collect more data about the ridge materials around us, and the sky above us, before embarking on a ~12 m drive to Sgurr of Eigg. We drove back into the Torridon quadrangle, so the target names once again have Scottish flavor. ChemCam shot three targets, each with a different characteristic. “Ben Stack” is a representative laminated bedrock target, “Ben Avon” is bedrock with small nodular features throughout it, and “Ben Lawers” includes a thin, resistant layer jutting out above the laminated bedrock surrounding it. APXS will also analyze a representative bedrock target, “Walsay,” but for reasons beyond just the normal chemical characterization of a target. APXS will analyze Walsay at four different distances - from touching the bedrock surface to hovering 3 cm above it - to refine how distance to the target affects APXS data. There are instances when the bedrock is rough enough that APXS cannot be placed directly in contact with a desired target. By conducting this calibration activity at Walsay, we will be better able to understand and interpret APXS data acquired in just such a situation.
The dust storm continues to envelop Curiosity, so our plan includes observations aimed at monitoring the amount of dust in the atmosphere at both early morning and midday times. We planned a dust devil survey, and a pair of cloud movies aimed at the horizon and at the zenith. ChemCam also took aim at the sky with a passive spectral observation to monitor the aerosols and trace gases in the atmosphere.
After the drive on Sol 2119, the rover will unstow her arm before imaging the workspace, providing the team with an unobstructed view of our next drill attempt site. Hopefully, we will be able to hit the ground running with our drill plan on Monday!
Sol 2120 update by Abigail Fraeman: A Little Bump (23 July 2018)
Our weekend drive completed successfully and we have our next intended drill target attempt in the rover workspace. Unfortunately, the combination of the rover’s pitch and roll would make future delivery of drilled sample to SAM via the new feed extended sample transfer (FEST) method impossible in our current orientation, so tosol we are going to scooch the rover over slightly to put it in a more favorable position for drill sample delivery activities.
The main activity for tosol is the small bump to get us into a good drill position. We also managed to get some science in before the bump. We will take a MAHLI image of “Sgurr of Eigg,” a contact science target from almost 120 sols ago, to see how much dust has deposited on it since we DRTed it. We will also take some ChemCam passive spectra from another familiar target, “Appin,” and then a Mastcam multispectral observation of both Sgurr of Eigg and Appin. We’ll finish out the morning science block with a Navcam dust devil survey and get some additional environmental science monitoring in the afternoon, including a tau observation and image of the crater rim to the north.
Sol 2121 update by Michelle Minitti: Blackjack! (24 July 2018)
Mars dealt us a winning hand today, yielding a sufficiently flat parking space after yesterday’s short bump to allow us to proceed with our plan to drill in this part of the “Vera Rubin Ridge.” Our current parking spot does not exhibit as strong a hematite signal from orbit as the site of our last drill attempt, but it still importantly provides an opportunity to sample the “Pettegrove Point” member of the Vera Rubin Ridge. Today we focused almost solely on characterizing the drill target, melodiously named “Ailsa Craig,” using MAHLI and APXS after brushing it with the DRT. The rover will also place the drill in contact with the target and push into it to test the target’s stability for drilling. If our luck continues, we will attempt drilling tomorrow! The science team managed to squeeze one observation unrelated to drilling into the plan - a single image of the sky to monitor the dust in the atmosphere.
Sols 2122-2123 update by Rachel Kronyak: Preparing to drill at “Ailsa Craig” (25 July 2018)
Yesterday, the science team chose a new drill target, “Ailsa Craig,” and we spent the day triaging the target with our contact science instruments, DRT, MAHLI, and APXS. The image above is one of the MAHLI images that we collected after the DRT removed some of the surface dust over the drill target.
Today, we’re planning two sols. Sol 2122 is devoted to drilling the target Ailsa Craig! We’ll collect some complementary observations to document our drilling activities with the Mastcam, MAHLI, and ChemCam RMI cameras. We’ll spend most of Sol 2123 recharging, but we also managed to squeeze in a few additional science observations, including two ChemCam LIBS analyses on nearby bedrock targets “Tolsta Head” and “Appin.” We’ll also use Mastcam to document two nearby crater features named “Taconite” and “Peterhead.” Finally, we’ll conduct some standard atmospheric tau and crater rim observations.
Sols 2124-2126 update by Ryan Anderson: It’s a Hard Rock Life (J27 July 2018)
Our attempt at drilling the target “Ailsa Craig” was partly successful: the drill behaved exactly as it was supposed to, but unfortunately we weren’t able to drill very deep. The rock here is just too hard! Since we didn’t get a nice deep drill hole, the plan for the weekend is to do some final observations at this location and then move on another location to try again.
The science block on Sol 2124 starts with a ChemCam passive observation of the pulverized rock tailings from our shallow drill hole. That will be followed by an “active” (laser zapping) observation of the vein target “LamLash Bay” accompanied by Mastcam multispectral images. Later in the afternoon, Mastcam and Navcam will do some atmospheric observations to monitor the dust levels as the planet-encircling storm gradually dies down. We’ll wrap up the day with APXS observations on and off of the drill hole.
In the morning of Sol 2125 Navcam and Mastcam have more atmospheric observations. Later in the afternoon, ChemCam will also analyze the chemistry of the drill hole and tailings and Mastcam and Navcam will do some more atmospheric measurements, including watching for dust devils.
On Sol 2126, Curiosity will drive toward our next potential drill location. We’ll collect the usual post-drive images to help us choose targets on Monday, as well as some more dust monitoring with Navcam.
Sol 2127 update by Christopher Edwards: Continuing to Understand Pettegrove Point (31 Aug 2018)
Curiosity completed its drive successfully after the science team regrouped from the incomplete drill, which required a different than anticipated weekend plan. The rocks of the Vera Rubin Ridge are just turning out to be harder than expected! In today’s plan, we will continue to assess the compositional diversity of the Vera Rubin Ridge Pettegrove Point member. In this workspace, we planned activities for two contact science targets, with APXS and MAHLI imaging of the locations dubbed “Diabiag” and “Slioch”. The Diabiag target has a purple hue in Mastcam imagery and appears to be relatively dust free, while the Slioch target is darker. The team could not find a suitable place to brush the dust away with a DRT activity since the local bedrock was extremely rough.
In addition to these contact science activities, multiple ChemCam observations were planned along with the Mastcam documentation images. These observations will complement the contact science activities. Over the next few days Curiosity will make its way to another location where we’ll try to drill again. Data from when Curiosity previously visited the site where we will attempt to drill again indicates that the rock might be a little softer than where we last tried to drill a few sols ago. In the next few sols, we’ll know more, but until then Curiosity will continue to characterize the diversity of the intriguing Vera Rubin Ridge.
Sol 2128 update by Ryan Anderson: In Search of Softer Rocks (31 July 2018)
On Sol 2128, Curiosity will continue toward our third potential drill site within the Pettegrove Point member of Vera Rubin Ridge, where we are hoping to find slightly softer rocks. The day will begin with ChemCam observations of the target “Slioch,” which was already analyzed by APXS, as well as the layered rock “Craignure Bay.” Mastcam will document both of these targets, using a small mosaic around Craignure Bay to capture images of some of the tilted rocks nearby as well. Then Navcam will do some atmospheric observations. After that, the rover will drive toward our next drill site and take some post-drive images. Navcam will do some more atmospheric measurements, and ChemCam will make an auto-targeted observation of the bedrock near the rover. We will finish off the plan with an 8-frame Navcam “movie” of the sky to look for clouds and measure the wind direction over Gale crater.
Hopefully tomorrow we’ll be close enough to do just a short bump to the drill site so we can try drilling again this weekend!
Sol 2129 update by Lauren Edgar: Dude, where’s my data? (1 August 2018)
Curiosity is currently on her way to a potentially softer rock target to drill in the Pettegrove Point member of Vera Rubin Ridge. Today was a late slide sol, which means we had to wait until 11am PDT for the downlink to arrive. Unfortunately, we didn’t get our downlink today from MRO. I was the SOWG Chair today, and it was an interesting morning as we had to quickly adjust the plan without knowing the current state of the rover. However, the team turned it around and made the most of the untargeted remote sensing sol. The geology theme group planned several autonomously targeted AEGIS observations of bedrock in the workspace, along with a Mastcam mosaic of the workspace and a Navcam mosaic of the ChemCam targetable region to prepare for targeting in the weekend plan. The environmental theme group took advantage of the day with two Mastcam tau and crater rim extinction observations, a Navcam line of sight and dust devil movie, and Navcam suprahorizon and zenith movies. All of this great environmental monitoring data will help as we continue to assess the ongoing dust storm. Looking ahead, we hope to proceed with science activities and driving in the weekend plan with the help of the Mars Odyssey spacecraft to relay data. Just another day and another challenge working on Mars!
Sols 2131-2133 update by Vivian Sun: Colors Abound in Pettegrove Point (6 August 2018)
Curiosity is currently preparing to bump to her next drill site in the Pettegrove Point member, but not before gathering many observations at our current location. There are interesting color variations in today’s workspace, with grey, tan, and red gradients across the outcrop that can be seen in the above image. Curiosity will document these color variations in detail with images from Mastcam and the Mars Hand Lens Imager (MAHLI) and chemical measurements from the ChemCam and Alpha Particle X-Ray Spectrometer (APXS) instruments. This is a lot of data to relay, but we expect downlinks from both the Mars Odyssey and the ExoMars Trace Gas Orbiter spacecrafts over the weekend.
On Sol 2131, the geology theme group planned ChemCam measurements of the targets “Shiant Isles” and “Inchnadamph,” which are grey-toned rocks. The observation on Inchnadamph is especially interesting because ChemCam will shoot two sets of 150 laser shots into the rock to see if there are chemical variations with depth. The APXS instrument will also make chemical measurements on a darker grey target “Mount Battock” and a lighter grey target “Scourie More,” in addition to a red target “Dobbs Linn” which will be brushed beforehand with the Dust Removal Tool (DRT). All of these targets will be documented with high-resolution Mastcam and MAHLI images.
On Sol 2132, Curiosity will acquire a Mastcam multispectral observation of all these targets to enable a detailed assessment of these color variations. Mastcam will also image the “Bullers of Buchan” target, which is an outcrop that may expose layering and nodules. Curiosity will then drive a few meters to our drill site.
Sol 2133 is packed with three science blocks filled with activities from the environmental theme group: Mastcam tau and crater rim extinction observations, Navcam zenith, suprahorizon, and dust devil movies, and Navcam line of sight observations. Curiosity will also make ChemCam passive measurements and an APXS atmospheric measurement. All of these observations will help with our ongoing monitoring of the atmosphere as the dust storm settles. After all of this, we look forward to seeing our drill workspace on Monday!
Sol 2134-2135 update by Rachel Kronyak: Third time’s a charm? (6 August 2018)
After a weekend full of contact science, remote science, and driving, Curiosity arrived at her next drill site within the Pettegrove Point member. Our previous two drilling attempts within the Pettegrove Point member haven’t been as successful as we’d have hoped; the rocks in this area are much harder than we’re used to - all the more reason to acquire and analyze a drill sample. We’re hopeful that our third drilling attempt does the trick!
Today we planned two sols to kick off our drilling campaign. On Sol 2134 we will perform triage contact science observations to document our new drill target, which we’ve named “Stoer.” We’ll use our Dust Removal Tool (DRT) to brush away some of the surface dust over Stoer before imaging it with the MAHLI camera and performing chemical analyses with the APXS instrument. To prepare for drilling, we’ll then perform a “pre-load” test, where we position the drill in contact with the Stoer rock surface and press down. This allows our mission engineers to verify that the rock is stable enough for drilling.
Later in the afternoon, we’ll assess the Stoer area with a Mastcam mosaic and perform some environmental monitoring observations with Navcam. Finally, we’ll place the APXS instrument on Stoer overnight to get a nice long chemical observation.
On Sol 2135, we planned a suite of remote science observations, including REMS, DAN, and Navcam atmospheric observations. After we move the robotic arm out of the way, we’ll perform two ChemCam LIBS analyses: one on Stoer, the other on the target “Strontian,” a nearby darker gray bedrock target. We’ll document both targets with Mastcam images and use additional camera filters to analyze Stoer; we call this observation a “multispectral” observation. We’ll end the day with a SAM electrical baseline test (EBT), which we periodically perform to monitor the SAM instrument’s electrical functions.
Sol 2136-2137 update by Sarah Lamm: Try, Try, and Try Again (8 August 2018)
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.
Sol 2138-2140 update by Catherine O’Connell-Cooper: Success at Pettegrove Point! (13 August 2018)
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.
Sols 2141-2142 update by Ashley Stroupe: Taking a closer look at the Stoer sample (13 August 2018)
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”.
Sol 2143-2144 update by Brittney Cooper: False Alarm! (16 August 2018)
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).
Sols 2145-2146 update by Christopher Edwards: Soliday Sunday (20 August 2018)
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.
Sol 2147 update by Mark Salvatore: SAM EGA on the Stoer Sample! (20 August 2018)
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!
Sol 2148 update by Melissa Rice: Well I’ll be DANed! (22 August 2018)
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.
Sol 2149 update by Roger Wiens: No Golf Courses on Mars…Yet (22 August 2018)
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.
Sol 2150 update by Roger Wiens: Delivering the Proper Portions (24 August 2018)
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.
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.
Sol 2154 update by Michelle Minitti: Look on the sunny side (28 Aug 2018)
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!
Sol 2155 update by Ryan Anderson: What a Dump (29 August 2018)
Our second attempt at a dump was successful! The plan for Sol 2155 starts with a whole slew of Mastcam images to check out various components of the arm turret, plus a MAHLI observation of the dump pile. After that, Navcam will look toward the crater rim to measure the amount of dust in the air, and ChemCam will analyze the targets “Ben Macdui” and “Tarskavaig,” both of which appear to be interesting features where the bedrock chemistry and mineralogy may have been altered. Mastcam will take pictures of these two targets once ChemCam is done with them, and will also document the previous ChemCam targets “Laig Bay” and “Bealach na Ba.” Mastcam will also take a high-resolution mosaic around the Stoer drill hole. In the late evening, MAHLI will take some pictures of the CheMin inlet funnel, and then we will place APXS over the tailings pile for an overnight analysis.
If all goes well, this will be the last full day at the Stoer location, and tomorrow Curiosity will start driving toward the south!
Sol 2156 update by Abigail Fraeman: The Story of Stoer (30 Aug 2018)
After an extremely productive couple of weeks, we are finishing up our work at Stoer! We'll take some quick ChemCam and Mastcam observations of the tailings dump pile tosols before packing up and starting our drive up the ridge towards our next drill location. As we leave Stoer, I'd like to take some time to share the story of how and why we came to drill this particular location.
We first attempted to drill Vera Rubin Ridge back on sol 2112 at the "Voyageurs" target. However, the drill made only a few millimeters of progress into that target before stopping because the rate of downward progress was so slow. The drill itself performed exactly as it was designed but the Voyageurs rock was simply too hard! It was pretty interesting from a science perspective to see this result, but it also meant we had to work quickly to figure out a plan B.
The science team agreed it was scientifically important enough to get a drill sample from the lower part of Vera Rubin Ridge that we should try again. But how could we improve our chances of finding a rock that would be softer and easier to drill than Voyageurs? It was time to think like geologists.
In the absence of direct data on rock mechanical properties, we came up with three criteria that we could use to try to find a softer rock. (1) Did the bristles of the DRT brush leave scratches on the rocks' surfaces? While not necessarily a direct indicator of what the rock strength would be when we drilled into it, we could at least say rocks that got scratched with the DRT had a softer surface than those that didn't. (2) How well exposed are the white calcium sulfate veins? On some rock targets, like Stoer, we clearly see veins. On other targets, like Voyageurs, the veins are recessed into the rock. Recessed veins erode much faster than the surrounding bedrock because the surrounding bedrock is harder. Non-recessed veins tells us the bedrock may be similar in strength to the veins, or, if the veins stick out, the bedrock may be lower in strength. (3) What does the large-scale topography tell us? Broadly, Vera Rubin Ridge is a ridge because it is composed of hard rocks that are more resistant to erosion than their surroundings. We realized we might use this same logic to find softer rocks within the ridge by trying to drill in local topographic lows or at bases of scarps where the bottom of the scarp is eroding more quickly than the hard rocks on top.
Fortunately, because we had already explored a lot of Vera Rubin Ridge, we already had lots of data in hand to search for our next drill targets. Several members of the science team put in impressive efforts to quickly go through all of the images we'd taken in the last 200 sols, and we found just a handful of candidates than fit our criteria. The area near "Ailsa Craig" was close to Voyageurs and looked different enough that we thought it was worth a go. We made more progress drilling into this target than Voyageurs, but still not enough.
"Stoer" was our final choice, and it was initially chosen because it was near the base of a scarp and had more prominently expressed veins. We all had a really good feeling about this target when we saw the DRT had scratched it, and were thrilled when we saw a successful drill hole. Apparently third time really was the charm for us!
Looking back on all the drills over the course of the mission, I think Stoer has got to be one of my favorites. Not only have I been personally wondering about the rocks on Vera Rubin Ridge for six years, but the fact that the science team worked so hard to find this not-so-hard rock makes this particular drill extra sweet.
Sols 2157-2158 update by Brittney Cooper: I'll Take the Quela To Go, Please! (4 Sep 2018)
Today in Gale Crater, Curiosity begins with a short (but sweet) science block that utilizes ChemCam, Mastcam, and Navcam to observe the Martian surface and atmosphere. We start off with a ChemCam LIBS raster of the target "Cairntoul," and then Mastcam mosaics of the same target, as well as "Monar Dam."
The block is finished off with a Navcam line of sight (LOS) observation to continue monitoring dust in the crater as the optical depth slowly wanes. The Navcam LOS differs from the other dust-monitoring observation, the Mastcam tau, by looking at the amount of dust in Curiosity's line of sight to the crater rim. The Mastcam tau determines the amount of dust in the entire atmospheric column by looking at the Sun in a controlled and protected way.
The sol continues with a drive to the new workspace where contact science will be planned over the weekend, and ends with an over-night cleaning of the SAM "scrubbers" and "getters" in preparation for the SAM noble gas experiment in the early hours of sol 2159. Sol 2158 is spent sleeping and recharging, with only REMS environmental monitoring taking place.
After charging up the batteries, Curiosity will wake up in the wee hours of 2159 to run the noble gas experiment that will hopefully constrain the geochronology of the "Quela Doggie Bag" sample. Curiosity has actually been carrying these "Quela" leftovers from drilling that took place close to the Murray Buttes for almost two Earth years - appetizing, right? In fact, the sample is in a perfect state to be run through the noble gas experiment, which will help team members understand how recently the outcrop has been exposed from beneath eroding rocks. The Murray Buttes have been retreating due to erosion - but at what rate? Hopefully this experiment can help clue us in.
Sols 2159-2162 update by Dawn Sumner: Lots of Bits! (4 September 2018)
Curiosity's plan for the weekend is extra large - 4 sols and almost 3 gigabits of data! We planned 4 sols due to the Labor Day weekend, and the hefty data volume is courtesy of extra downlink from two special orbiters. Curiosity sends her data back to Earth through various orbiters around Mars. Usually, we use the Mars Reconnaissance Orbiter (MRO) and Mars Odyssey (ODY) to transmit our data, and we get an average of 500 megabits of data per sol. (Note that 8 bits = 1 byte, so our average bandwidth is about 60 megabytes of data per sol. In contrast, DSL bandwidths are ~10 megabytes per second, so we get about 6 seconds worth of internet per sol!)
Recently, we have been getting lots of extra downlink. NASA's InSight mission will land in November, and MRO will be dedicated to relaying InSight data for its prime mission. Curiosity will shift to downlinking data through NASA's Mars Atmosphere and Volatile Evolution (MAVEN) orbiter and the European Space Agency's Trace Gas Orbiter (TGO). In preparation, we have been downlinking extra data using MAVEN and TGO. This has allowed us to downlink a backlog of images. In today's plan, we were able to take some large multispectral mosaics to fill an extra ~2 gigabits of downlink we expect next week. That's an extra 4 sols worth of bits!
Our activities include recharging the batteries on sol 2159. On the next three sols, Mastcam will take multispectral mosaics of "Tayvallich," "Rosie," "Rhinns of Galloway," and "Ben Haint" plus an image of "Ben Vorlich." ChemCam will analyze "Ben Vorlich" with LIBS, and ChemCam, APXS, and MAHLI will analyze "Tayvallich." It's time to check our instrument calibrations, and APXS will integrate overnight on its calibration target to better constrain dust that settled during the recent dust storm. MAHLI will image both the MAHLI and APXS calibration targets on sol 2161. ChemCam then takes its turn for characterizing dust by observing the passive spectrum of the white part of the Mastcam calibration target with a magnet under it, followed by passively observing the sky. After all of this imaging, Curiosity will drive toward our next drill location, and we hope to end within 15 m of our next drill site. Mastcam will take multispectral images of that area to help us choose the exact spot. Sol 2162 focuses on collecting environmental data, including a sky survey and an image of the crater rim to compare dust levels in Gale Crater with those in the atmosphere as a whole.
It's an extra large plan! And we will enjoy the long weekend - planning doesn't resume again until Wednesday.