Curiosity update, sols 1675-1725: Traverse to Vera Rubin Ridge

Curiosity has had a busy eight weeks since my last update, driving south from the Bagnold Dunes toward Vera Rubin Ridge. The path has steepened and the rover is now rapidly climbing upward with every meter traveled. The science team has been systematically observing bedrock with about every 5 meters of elevation gain using MAHLI and APXS instruments, but there's been no drilling. A problem with the brake on the rover's drill feed mechanism that occurred back in December is still preventing its use, and there's currently no estimate of when (if ever) it will return to action.

Two of Phil Stooke's maps illustrate the recent travels, and show Vera Rubin Ridge ahead:

With limited resources of power and operation time, the Mars Science Laboratory mission often has to choose between spending time driving and doing science. During the last two months, the priority has been driving. However, unlike in past intense driving periods, Curiosity has been limited to shorter total drive distances, usually under 50 meters and mostly under 30 meters per day. The main limitation is visibility: the Murray formation is getting blockier, with tipped-up boulders presenting obstacles in the way of the rover's forward vision. Even if the rover drivers plan a safe route around boulders, they can't see what's behind the boulders, and that's limiting total drive distance.

But what's bad for drive distance is a boon for traverse science. If the rover is limited to 30 meters in a day, there's more time and power available for science. The project science leadership has directed the mission to use the MAHLI camera and APXS elemental abundance measuring instrument to investigate the appearance and composition of the Murray unit at least every 5 vertical meters. The rover is now ascending a slope with an approximately 10% grade -- that is, every 10 meters of map distance upslope is also 1 meter in elevation gain. The rover doesn't often attack the slope straight-on, so it has to drive more than 50 meters to gain 5 meters, but still -- it typically only takes 2 or 3 good drive sols to get from contact science site to site. It's not enough to just do contact science on weekends anymore; the rover needs the use of its arm mid-week.

One piece of good news about the changing terrain: despite the increasing blockiness of the Murray, there's been no acceleration in wheel damage. Rover drivers can steer around many of the blocks. Even when wheels have to confront rock, Murray formation rock is soft enough that Curiosity's wheels tend to crush it, unlike the Bradbury rocks that used to puncture the wheels' thin skin.

The shifting of seasons is also giving science a bit of a boost. May 5 was the autumnal equinox at Curiosity's southern-hemisphere location. The temperatures are getting colder. In general, cooler temps make operations more difficult: colder temperatures limit when the rover can drive without having to preheat its motors. But cooler temps are beneficial for the APXS instrument, which gets better-quality data, the colder it is. Morning temperatures are cool enough now that APXS can get a good-quality reading of a target's composition in only 20 minutes of bouncing alpha particles off of it. They can spend half an hour to an hour on science, reaching out to cool outcrops like this one, and then drive on. These are called "touch-and-go" or TAG operations, and they are making Curiosity remind me of Spirit and Opportunity.

Another fun event happens close to the equinoxes: there is a period of weeks when the moons, Phobos and Deimos, transit the Sun as seen from Mars. Curiosity has attempted to acquire movies of a couple such passages, and also saw Phobos' shadow darkening the slopes of Mount Sharp.

Even if APXS is having an easier time getting quick data, it can be frustrating for scientists to have to cram all their science in to quick morning sessions before drives. So the science team was not entirely disappointed when a problem with the Deep Space Network on sol 1713 resulted in the rover spending a weekend at a very interesting science spot. As the rover approaches the top of the Murray formation, the science team has been noticing layers of a gray-toned rock that's distinctly different from the pink and orange material they're accustomed to. Here, Curiosity uses MAHLI to get low and examine the contact between typical Murray and the gray-toned layers at a site named "Prays Brook" on sol 1714.

The view to the south of the rover on sol 1720 shows Vera Rubin Ridge blocking further progress. The rover will now turn to the east, contouring along the base of the ridge for a little while until it reaches a ramp of sorts, a safe location to climb up onto the ridge top. There Curiosity will finally be able to put its instruments onto rocks where orbiters unequivocally saw water-related minerals. The rover will also get its first look at the clay-bearing layers beyond the ridge.

Beyond the ridge and the clays, Mount Sharp rises. Much of this mountain will never be physically explored by Curiosity, but ChemCam's camera is shooting telescopic views of the interestingly eroded shapes in the mountain slopes.

Drill Update

As Curiosity approaches the top of the Murray formation and journeys into new rock units, it would be a really good time for the drill to come back into service. Unfortunately, there is no estimate for when that may happen. Engineers have been hard at work testing the drill, trying to develop methods to reliably advance the drill feed. Project scientist Ashwin Vasavada tells me that the experiments they've been performing have borne some fruit but have not led to a solution that allows the drill feed to function reliably.

They're shifting now from trying electronic solutions to the balky drill feed (like adjusting voltages, using one or the other or both brake coils) to mechanical solutions (experimenting with the orientation of the drill and with the use of vibration and percussion at different levels). And because it's been so long since the last successful drill attempt, on sol 1495 at Sebina, the project is beginning to expend some effort to explore some "less standard uses of the drill" that would bypass the use of the drill feed altogether for sampling activity. Let's all hope it doesn't come to that, but I'm glad they're preparing for the possibility that the drill feed mechanism might be unrecoverable.

Mission Science

In the last two months, the Curiosity team has published two important papers about the geologic history of Gale craters. Joel Hurowitz et al. published in Science: "Redox stratification of an ancient lake in Gale crater, Mars." Elizabeth Rampe et al. published in Earth and Planetary Science Letters: "Mineralogy of an ancient lacustrine mudstone succession from theMurray formation, Gale crater, Mars." Both look closely at the same data to draw different conclusions about the chemistry of the waters that once pooled in the bottom of the crater. Although the papers present somewhat different results, several scientists are coauthors on both papers. I haven't done a close side-by-side reading of the two papers to understand how they differ yet, but I will.

And that's it for this update. I'll likely write next when Curiosity has reached the top of the ridge, unless something else more exciting happens! And now, please enjoy the concatenated mission updates for this period. The fresh voices on the mission updates have been doing a particularly good job of late explaining the science decisionmaking process in their blogs.

Sol 1677 update by Abigail Fraeman: Some Murray in hand (April 24, 2017)

This morning we woke up to fresh images from Curiosity that showed our surroundings after an ~17 m Sunday afternoon drive. I always really enjoy days like this because, even after 1,676 sols and just under 16.1 kilometers of driving, it still thrills me to look at images from unexplored areas of Mars. Immediately after inspecting the data, the science team jumped into planning by debating whether we wanted to spend the morning of Sol 1677 doing remote sensing, or if we wanted to spend the time doing contact science with the arm, all before an early afternoon drive continuing up Mt. Sharp.

A big part of the science team strategy for exploring the Murray formation, the group of rocks that are the lowest and oldest in Mt. Sharp, has been to systematically characterize their changing chemistry and mineralogy. Understanding how these properties vary with elevation gives us insight into changing conditions in the geologic processes that deposited and altered these rocks during burial. Because two of Curiosity's wheels were perched on rocks during Friday's planning, we were unable to safely use the arm to measure their chemistry using the APXS (Alpha Particle X-Ray Spectrometer). Since we had the opportunity to make these measurements again today and since the rover wheels were in good contact with the underlying terrain, we easily agreed we would shorten our remote sensing block and instead use the morning time to take advantage of the opportunity for contact science.

The area directly in front of the rover was filled mostly with sand, but we were pleased to find there was a small patch of Murray bedrock that we were able to reach with the arm and that wasn't filled with white veins. While veins and filled fractures are extremely interesting and frequently targeted for study, their presence in the field of view of the APXS makes it more difficult to understand the changing chemistry of the primary Murray bedrock. We named our contact science target "Casco Bay" and planned both MAHLI and APXS observations of it. We also managed to have enough time in the plan for a little bit of remote sensing, and used that to take ChemCam observations of Casco Bay that will complement the contact science measurements. We also planned to take several Mastcam color images to help us document the geologic context of our surroundings. Environmental science also requested a dust devil movie plan. After our morning science block, we planned another drive to continue our way up Mt. Sharp.

Sol 1678 update by Ken Herkenhoff and Lauren Edgar: A smooth planning day (April 26, 2017)

MSL drove another 33 meters on Sol 1677, and again is surrounded by rocky outcrops partly covered by dark sand. Although Rover Planner support was available for "touch and go" contact science, the GEO science theme group decided that the limited reachable outcrop did not warrant contact science, and that driving is the top priority for this plan. APXS data were successfully acquired on Sol 1677, so are not urgently needed in this new location. The plan for Sol 1678 therefore focuses on remote sensing, with ChemCam 10x1 rasters on "Hancock Point," a darker exposure of bedrock, and "Crocker Mountain," a more normal-looking bedrock exposure. Mastcam context imaging of these targets will be followed by mosaics of nearby exposures that show sedimentary structures. Because the drive plan is likely to end up with bedrock in the arm workspace, we added a 3x2 Left Mastcam mosaic of the workspace to the post-drive imaging block, in case we can plan a touch and go tomorrow. Two ChemCam AEGIS activities and a Navcam zenith movie are planned after the drive. Thanks to the efficient work done by the science theme groups, planning went very smoothly today, making it an easy day for me as SOWG Chair.

Sol 1679 update by Abigail Fraeman: Another day of TAG (Touch and Go) (April 26, 2017)

Our drive yestersol went as planned and added another 28.3 meters to Curiosity's odometer. The science team was pleased to see that more interesting outcrop would be reachable by Curiosity's arm from our new location, so we decided to plan contact science followed by an afternoon drive in the Sol 1679 plan. We call sols like this "Touch and Go" sols. Curiosity will be examining interesting color variations in the rock target "Maple Spring" using MAHLI and APXS. We also had a few minutes left in the morning to allow us to take ChemCam observations of Maple Spring that will complement our contact science observations. After the morning science, Curiosity will go for an afternoon drive, followed by some post-drive imaging, environmental science observations, and automated targeting of the ChemCam instrument using the AEGIS (Autonomous Exploration for Gathering Increased Science) software.

I didn't participate a lot in the science team planning discussions today because I was staffed as a Surface Properties Scientist (SPS). In this role, I work closely with Rover Planners (RPs) as they design a sol's drive, lending my geologist's eye to provide feedback on the traversability of the terrain ahead. In particular, I look for any potential mobility hazards that might include wheel-damaging rocks, sand that could lead to high slip, or any other features that might pose a problem for our mobility system. I've often found it's useful to take a glance in our rearview mirror, or Rear Hazcam to be precise, to look at our tracks to understand how much we sank in the sand and how thick the sand cover is. It's also important to check out the terrain around us in 3D using stereo red-blue anaglyphs or, even better, virtually walk along our planned drive path using augmented reality in a Microsoft HoloLens running OnSight. I'm looking forward to seeing where we end up tomorrow!

Sol 1680 update by Michael Battalio: Mesmerized by the Murray Formation (April 28, 2017)

After a 30 meter drive on Sol 1679, we find ourselves near diverse outcrops of the Murray formation. We plan to drive on today across the Murray formation towards Vera Rubin Ridge.

I helped the ENV (Environmental) group to train a new ESTLK (ENV Science Theme Lead and Keeper-of-the-Plan) today. Unlike the GEO group, ENV combines the two roles into one to reduce staffing and because the required duties are lighter in ENV. The ENV plan was relatively straightforward as we are in unrestricted sols, which allow for planning (and driving) every day of the week. This makes time for science, a precious commodity, so ENV frequently cuts back on opportunistic science as long as the regular cadence of recurring ENV observations can be maintained. To stay on the usual cadence, ENV planned a Navcam zenith movie and supra-horizon movie, like the clear-sky image pictured above from Sol 1675. The normal complement of background RAD measurements, hourly REMS observations, plus 8 hour-long blocks of extended REMS observations were included. One long DAN passive observation, along with a post-drive DAN active observation were planned.

Unlike the previous few sols, GEO decided to forgo a touch-and-go (see Sol 1679) to instead sample the large array of outcrops of the Murray formation. Four ChemCam 5x1 rasters, with accompanying Mastcam images, were planned on several targets, including laminated bedrock "Trenton Bridge," bedrock targets "Brown's Brook" and "Beach Cliff," and a pebble named "Norwood Cove." A Mastcam mosaic of the sedimentary structures at "Birch Spring" was also planned. Finally, Navcam requested a single frame to complete the 360 mosaic acquired on Sol 1679. After the drive, which is expected to be about 30 m, a ChemCam AEGIS activity plus Mastcam deck monitoring were included with the ENV activities mentioned above.

Sol 1681-1683 update by Michael Battalio: Kicking the Tires (April 28, 2017)

After a drive of almost 29 meters, we are parked at a site suitable for a busy plan full of contact science on the Murray formation. GEO focused mainly on characterizing nearby flagstone - "Duck Brook Bridge" was like the typical Murray formation that was tan in color, and "Cliffside Bridge" and "Waterfall Bridge" were more coarse-grained and gray. ChemCam will observe all of those targets, and APXS will measure both Duck Brook Bridge and Waterfall Bridge, with a long integration on Duck Brook Bridge. Mastcam observations will support that targeted science in addition to obtaining mosaics of fine-scale laminations on the "Stanley Brook Bridge" contact and alternating layering on "Chasm Brook Bridge." In the final targeted science block on Sol 1682, ChemCam will observe "Amphitheater Bridge" and nodule-rich "Cobblestone Bridge." A major component of the plan is the MAHLI full-wheel imaging that is periodically done to ascertain the state of the rover wheels. This is being done slightly earlier than usual in preparation for traction control driving (see Sol 1646 for more). Finally, after a drive, ChemCam will perform an AEGIS activity, and the usual post-drive imaging will be performed.

I worked the ENV STL role today and was busy planning a morning imaging suite for Sol 1683. In the suite, Navcam will search for clouds looking both directly above (zenith movie) and across the horizon (supra-horizon movie). Mastcam will measure the amount of dust in the atmosphere in two directions: in the direction of the sun and towards the crater rim - called a line-of-sight (LOS) extinction. Each of these measurements will be repeated in the afternoon to determine what, if any, diurnal changes occur. A 360 degree dust devil search like the one pictured above from Sol 1675 looking towards Mt. Sharp will be captured on Sol 1681. There do not appear to be dust devils in that image, but other sets of enhanced images have been more fruitful. Finally, a Navcam LOS extinction measurement will be taken for comparison with Mastcam. Normal REMS and RAD measurements as well as several DAN passive measurements and one DAN active were planned.

Sol 1684 update by Christopher Edwards: Touch and Go or Just Go? (May 2, 2017)

Today was a day of tradeoffs. Should Curiosity focus on driving to get to a higher priority target sooner, or conduct contact science at the current location? Ultimately the Geology Theme Group decided to forgo the "touch-and-go" option, in which contact science is carried out prior to driving, and instead focused on using that time to increase the drive distance. With today's drive, the hope is to make it about 50 meters down the road along the strategically planned path informally known as the "Mt. Sharp Ascent Route." At the end of today's drive, the plan is for the rover to end up within about 2 meters of an intriguing gray hued target, having made significant progress towards a "megaripple" of high interest for helping to further our understanding of Martian aeolian processes. Megaripples are thought to form when the wind regime is not strong enough to move larger particles but still strong enough to move some of the smaller particles by saltation (that is, by bouncing short distances across the surface). Previously, Curiosity has visited several locations associated with the Bagnold Dunes where the rover is conducting a detailed assessment of variability and properties of the dune field as a whole.

Before Curiosity drives, away several ChemCam activities were planned including observations on the targets "Cow Ledge" and "Carter Cove." The "Carter Cove" target is located on the darker, more knobby, layered outcrop in the upper left of the accompanying Navcam image. Both of these targets are aimed at refining our understanding of the compositional and textural variability present in the Murray formation. Additionally, Mastcam documentation images of these targets will be acquired along with the documentation of the autonomously selected AEGIS target acquired after the previous sol's drive. An extension of an existing Mastcam mosaic was also planned, to provide additional context along a section of the exposed Murray outcrop.

Following the drive, we planned some standard imaging to help with targeting in the next sol's plan as well as a ChemCam AEGIS target, designed to autonomously measure bright patches of outcrop in the Navcam scene. All in all, a good day's work on Mars.

Sol 1685 update by Christopher Edwards: Touch and Go or Just Go (Again)? (May 3, 2017)

Planning rover science activities is a dynamic process. Unlike yestersol's plan, the Geology Theme Group decided to include an APXS and MAHLI "touch-and-go" in the plan, carrying out valuable contact science on the layered Murray bedrock. A touch-and-go, and in this case with a small APXS raster, is an option often available tactically to the Geology Theme Group that enables contact science to be carried out prior to a drive. Touch-and-go contact science activities, when appropriate, let the science team acquire the most information on a target without bringing a sample onboard the rover to instruments like CheMin and SAM. What makes these touch-and-go activities so valuable is that they have minimal impact to the drive distance for that day, allowing Curiosity to continue its ultimate goal of characterizing the geologic units of Mt. Sharp.

In this case, the APXS integration spots, dubbed "Harding Ledge" were also targeted with the ChemCam instrument to provide cross-correlation between the two instruments. Harding Ledge is a light toned, layered portion of the Murray bedrock. Some additional Mastcam documentation images were taken of the various targets in today's workspace to ensure proper context for the chemistry measurements is available for future investigations.

While yestersol's successful drive ended a bit prematurely due to the rough terrain the rover encountered, a new drive of ~20 meters is in the plan for today. At Curiosity's next parking spot before the sun sets, the rover will acquire a host of standard imaging to help with targeting in the next sol's plan.

Sol 1686 update by Michael Battalio: March to the Megaripples

Continuing the steady march up Mt. Sharp, Curiosity drove 18.3 m to bring us closer to a series of features being called megaripples, which are darker and larger ripples than were seen on the Bagnold Dunes. Touch-and-go was again the option for this plan (see Sols 1684 and 1685), and GEO made use of it with contact science on two targets, "Newport Ledge" and "Sugarloaf Mountain." These two targets are the closest two rocks protruding above the sand in the Navcam image above. MAHLI will target Newport Ledge to gauge grain size and distribution. A series of observations by APXS and ChemCam on Newport Ledge will continue to investigate the variations in the Murray bedrock over the course of the ascent up Mt. Sharp. Mastcam will target Newport Ledge and Sugarloaf Mountain to look at stratification and layering. After a drive that should take Curiosity to the edge of the megaripples, ChemCam will perform an AEGIS activity, and Navcam will document the new surroundings.

In working as the ENV theme lead today, I planned a pair of afternoon dust observations with Mastcam, looking in the direction of the sun and towards the crater rim (a line-of-sight extinction). As usual, REMS will capture the top of the hour five-minute observations and hour-long blocks of environmental measurements. In addition, a two-hour block of high-resolution data for the humidity sensor will be taken in the early morning. The high-resolution capture of humidity data is only sparingly used because it requires the ground temperature and wind sensors to be turned off as the heat they generate interferes with the humidity measurements. A DAN passive and post-drive active measurement will be acquired as well.

Sol 1687 update by Michelle Minitti: Mega-science at a megaripple! (May 5, 2017)

The rover planners executed another great drive to park us in front of a megaripple in order to study its physical and chemical characteristics, which we can compare and contrast to the sands we investigated during our recent Bagnold dune campaign.

As the geology (GEO) theme group lead today, my job was to make sure we planned the highest priority observations of the megaripple, and positioned ourselves to successfully complete all the desired observations of the megaripple in the upcoming weekend plan. Working with my fellow GEO group members and all the individual instrument teams is one of the most satisfying parts of the job, as everyone brings their experience and capabilities together to build a plan that gets the most science out of the rover each sol. We certainly put Curiosity to work, planning MAHLI and APXS observations of the target "Schoolhouse Ledge" along the ripple crest, and the target "Man of War Brook" along the flank of the ripple. To keep the structure of the ripple crest pristine for MAHLI imaging, we shot ChemCam across another part of the ripple crest, the target "Gilpatrick Ledge". We also used ChemCam to interrogate the target "The Gorge", located inside the wheel scuff the rover planners purposely cut into the ripple to expose its interior structure. GEO planned a Mastcam observation using filters at specific wavelengths of light that help constrain what iron-bearing minerals are present within the sands. The target for this observation was "Cobbosseecontee Lake", which one of our Maine-dwelling team members insisted was not challenging to say (it is actually pretty phonetic…)! Even with our focus on the megaripple, there was still time to image the rocks around us with Mastcam, including an expanse of well-layered bedrock south of us called "Amphitheater Valley". Last but not least, GEO started a series of MARDI images - one image acquired each evening we are parked at the megaripple - to look for wind-induced changes. These change detection images help the team understand if (or how) wind activity and direction are changing as we leave the Bagnold dunes. Speaking of winds, the environmental (ENV) theme group planned a dust devil survey to look for those telltale signs of wind activity. ENV also acquired a long DAN passive observation, and regular RAD and REMS measurements.

Sol 1688 - 1690 update by Abigail Fraeman: Sand between our grousers (May 8, 2017)

Today was a Friday so we put together a three day plan to cover the weekend activities, or in Mars-speak, sols 1688 - 1690. We've been getting some really interesting data down from our investigation of a large sand drift (megaripple), so we packed in many more observations to assess the full variability of the sandy materials before driving away and continuing our climb up Mt. Sharp.

Over the weekend, we are planning to take APXS and MAHLI observations that focus on the materials inside the area of sand that was scuffed by the wheel ("Little Notch"), and also some bright undisturbed materials ("Cold Ledge"). We will also take MAHLI only observations of different undisturbed portions of the megaripple at "Schoolhouse Ledge" and "Man of War Brook". In addition to contact science, we will take many Mastcam images, including a full 360-degree mosaic, a mosaic of our future drive target ("Buttermilk Brook"), a multispectral observation of some vein targets ("Eddie Brook"), and images of a handful of interesting nearby rocks ("Little Harbor Brook", "Bubble Brook", and "Marshall Brook.") We're rounding out remote sensing observations in the plan with ChemCam observations of "Stanley Brook", "Chasm Brook", and "Denning Brook", and a post-drive automated ChemCam AEGIS activity. The environmental theme group also included a dust devil survey, measurements of dust in the atmosphere, and horizon movies.

For tactical planning today, I was again staffed as a Surface Properties Scientist (SPS), so I worked closely with the rover planners (RPs) to help plan the drive to an interesting location ~20 meters away. We can see in the Mastcam images that there are some rocks that have colors and textures different from the typical outcrops we've been seeing during the majority of our ascent, so the science team is eager to drive over and check out this area up close. I look forward to seeing our new location Monday morning when the data come down.

MAHLI Image of sand: https://mars.nasa.gov/msl/multimedia/raw/?rawid=1687MH0007000010603742E01_DXXX&s=1687
Mastcam image of sand scuff: https://mars.nasa.gov/msl/multimedia/raw/?rawid=1686ML0087720020700897E01_DXXX&s=1686

Sol 1691 update by Ryan Anderson: Stopped Short at Green Nubble (May 8, 2017)

The weekend drive stopped a little bit short of the target, but that's ok because it put the rover in reach of some interesting cross-bedded rocks. We decided to do a "touch and go" plan for Sol 1691, quickly analyzing the rocks in front of us and then continuing on to the original drive destination.

The plan starts off with MAHLI observations of the targets "Ike's Point" and "King's Point". ChemCam will then analyze the target "Green Nubble" and Mastcam will take a documentation image of the same target. Mastcam will also document the auto-targeted ChemCam observation from the weekend plan and take a few frames to connect the workspace and drive direction images. Finally, Mastcam has a small mosaic of "Androscoggin River". After that, the rover will do a short drive followed by post-drive imaging, an auto-targeted ChemCam observation, and a MARDI image of the ground under our wheels.

In the morning of Sol 1692 Mastcam will make its first of three attempts at imaging Mars' moon Phobos passing in front of the sun, which allows us to refine our understanding of its orbit. The Phobos transit observation will be followed by Mastcam and Navcam observations to measure dust in the atmosphere, as well as a couple of Navcam movies to look for clouds.

Sol 1692 update by Rachel Kronyak: Science frenzy! (May 9, 2017)

After the drive on Sol 1691, the workspace in front of the rover had plenty of interesting rocks in front of us to keep us busy.

Today I served as the Payload Uplink Lead-1 (PUL-1) for Mastcam, which means that I worked closely with the Geology Theme Group and other Mastcam PULs to make sure the images we take best capture the requests of the science team. Much to our delight, today’s plan is chock-full of fantastic Mastcam mosaics!

The plan starts off with several ChemCam observations to analyze the targets "The Maypole," "Weaver Rock," and "The Cleft," along with their corresponding Mastcam documentation images. We will then take a series of Mastcam mosaics on the targets "Ox Hill," "Old Tom," "Bear Island," and "Bowden Ledge" to characterize sedimentary structures and bedding features. We will also take a Mastcam image of yesterday’s automated ChemCam AEGIS observation to provide context for where the target ended up. Finally, we will take a Mastcam image of the rover deck, which we do periodically to monitor saltating material (loose grains being jostled around by the wind) near the height of the deck.

Curiosity will then use its robotic arm to take MAHLI images of the targets "Pejebscot Falls," "Sagadahoc Bay," and "Myrtle Ledge." That’s a grand total of 10 new targets in the today’s plan - it’s sure to be a busy day on Mars! We will close out Sol 1692 with a late-afternoon Mastcam observation of Mars’ moon Phobos transiting in front of the sun and an overnight APXS analysis on Sagadahoc Bay.

Sols 1693-1694 update by Rachel Kronyak: Remote science and onward! (May 10, 2017)

Today we planned two sols, 1693 and 1694. On the first sol, we will conduct a suite of remote science observations before driving away and resuming our trek up Mount Sharp. These remote observations include a combination of atmospheric and bedrock measurements, giving us a really thorough dataset at this location. Our atmospheric observations include a ChemCam passive sky, Navcam zenith movie, suprahorizon movie, and a few Mastcam images that will help us measure atmospheric scattering.

For our bedrock observations, we will be conducting two ChemCam rasters and a Mastcam multispectral activity on the dark bedrock target named "Bear Island" that can be seen in the upper left in the image above. We got our first look at Bear Island in yesterday’s plan and decided it was an interesting enough target to warrant further investigation by ChemCam and Mastcam.

Following our remote science observations, we will drive away and take some post-drive images to set ourselves up for a busy weekend of exciting contact and remote science! After the drive, we will be taking our third round of Phobos transit images with Mastcam as well as an automated ChemCam AEGIS observation. On sol 1694, we will conduct a Navcam dust devil movie and calibrate the ChemCam instrument.

Sols 1695 -1697 update by Michelle Minitti: Observations of land, rover and sky (May 15, 2017)

Curiosity continued her detailed investigation of the interesting suite of outcrops we have been picking our way across during the last week. As we climb up Mount Sharp, recently over slopes of 4-6 degrees, we have seen more varied outcrop structures and chemistries than the rest of the Murray formation, and such changes catch the collective eye of the team. Today's plan will keep Curiosity busy throughout the weekend, investigating some of these unique rocks.

One target in the workspace in particular, "Mason Point", will get the royal treatment with five separate science observations directed at it. The reason it will receive such attention is that it will be brushed by the Dust Removal Tool (DRT), removing the thin veneer of obscuring dust that has settled on the rock surface. From the brushed Mason Point target, we will obtain MAHLI images to study the target's texture and grain size, ChemCam and Mastcam spectra of the light reflected off the surface to constrain mineralogy, and an APXS analysis to get chemistry. We will also analyze the chemistry of Mason Point with a ChemCam raster, but before it is brushed. Why? ChemCam's laser not only probes chemistry, it clears dust! The comprehensive and complementary datasets obtained from Mason Point will further our understanding of this target better than any single analysis would alone.

Mason Point will get the most focused attention, but the analysis of many other targets will help the science team probe the overall variety of the rocks in this area. MAHLI, APXS and ChemCam will study "Mitchell Hill", a bedrock target exhibiting prominent layering. ChemCam will also shoot "Mount Gilboa" to gather not only chemistry but grain size data for this target. Mastcam mosaics centered on Mitchell Hill and "Manchester Point" will capture orientations of layers in these targets that might help reveal how the layers formed.

In a change of pace from looking at rocks, Curiosity invested time in the plan acquiring images with MAHLI that monitor the health and performance of the instrument. MAHLI imaged her calibration target, which contains well known color and geometric targets that offer a test of instrument performance. MAHLI also imaged the APXS calibration target, a slab of finely polished basalt that serves as a chemistry standard for APXS. MAHLI then turned her eye to the sky, purposely acquiring images of featureless parts of the sky. These images, called sky flats, help reveal the presence of dust on the MAHLI lens. Just like dentist appointments, calibration "checkups" occur about every six months. Happily, MAHLI checkups are pain free.

After the rover planners drive Curiosity over 50 meters along our strategic drive path, Mastcam and Navcam will obtain a number of images and movies used to measure the amount of dust in the atmosphere, scan the atmosphere for dust devils, and search the sky overhead and near the horizon for clouds. These environmental observations will be complemented by DAN passive and active measurements that seek subsurface hydrogen; RAD measurements that monitor the radiation environment at the surface; and REMS measurements that give us our regular Martian weather reports.

Sols 1698-1699 update by Scott Guzewich: It's Touch and Go on the Climb to Vera Rubin Ridge (May 16, 2017)

The road to Vera Rubin Ridge, a feature believed to be enriched in the mineral hematite, is getting steeper, so we are stopping frequently to study the composition of the bedrock beneath our wheels. Our intention is to use the APXS and ChemCam instruments to analyze the bedrock for every 5 meters of vertical elevation gain to see how it may change as we climb toward Vera Rubin Ridge. And we are climbing fast on many of our drives now!

Today I was the Environmental Science Theme Group Lead as we planned Sols 1698 and 1699. Our first activity was a "Touch and Go", where we used APXS and MAHLI to study the bedrock (today at a location called "Woodland Ledge", in the lower right corner of the image) before driving ~50 meters southeastward to our next destination. We also targeted ChemCam and Mastcam to some nearby interesting rock targets named "Spurling Rock", "Grindstone Ledge", and "Knight Nubble".

Following the drive on Sol 1698, we will have a post-drive DAN active measurement and the 3rd set of Mastcam atmospheric observations on this sol. Having multiple measurements in a single sol helps us understand how amounts of atmospheric clouds and dust vary between morning, afternoon, and evening. On Sol 1699 we're planning untargeted science including a ChemCam AEGIS activity and a Navcam dust devil survey image sequence.

Sols 1700-1701 update by Michael Battalio: Optical depth measurements (May 17, 2017)

Curiosity continues towards Vera Rubin Ridge with a 48 m drive. GEO decided for the touch-and-go option (instead of lengthening the drive like on Sol 1684) using APXS and MAHLI on "Ripple Pond," a typical member of the Murray formation. Mastcam and ChemCam will follow up with observations of Ripple Pond. Mastcam will next target "Rhodes Cliff," which is especially interesting as it is tilted to show the Murray formation layers. Following these observations, Curiosity will drive and capture standard imaging for targeting in the weekend plan. After the drive, ChemCam will perform an automated AEGIS activity to measure bright patches of outcrop.

In working as the ENV theme lead today, I planned several observations to maintain the usual ENV cadence activities. Two measurements of dust in the atmosphere will be captured by Mastcam on Sol 1700. One measurement will determine the optical depth vertically (tau), and a second will determine the amount of dust towards the direction of the crater rim (line-of-sight). Optical depth describes the amount of light attenuated (scattered or absorbed) above Curiosity. An optical depth measurement, or tau, is defined as the logarithm of the ratio of the transmitted energy flux through some layer of the atmosphere to the received energy flux. By looking directly at the sun with Mastcam, the amount of energy reaching the surface can be determined. This is the transmitted flux through the entire atmosphere. Combined with an estimate of the incident energy from the sun at the top of the Mars atmosphere from satellite observations (the received flux), a reliable measurement of the optical depth for the entire atmosphere can be made. The second dust measurement - a line-of-sight extinction (LOS), like the one pictured from Sol 1670 - does a similar calculation to the tau, except horizontally instead of vertically. On Sol 1701, Navcam will capture a supra-horizon cloud movie and will perform an independent LOS measurement for comparison to the Mastcam measurement. Finally, a dust devil movie will be taken around local noon. Normal REMS and RAD measurements as well as several DAN passive measurements and one DAN active will be captured.

Example tau image from Sol 1670

Sols 1702-1704 update by Michelle Minitti: An island of science (May 22, 2017)

The rover planners parked us in front of the one slab of outcrop - an island among ripples of sand - we could safely drive to from our Sol 1700 position, setting us up to continue our exploration of the Murray formation.

The outcrop slab exhibited color variations (gray, pink and orange) and patchy white veins, so to capture these variations the science team analyzed multiple spots on the outcrop with MAHLI, APXS, ChemCam and Mastcam. We brushed dust off the target "Fern Spring" with the DRT and analyzed two separate spots within this dust-cleared area with APXS. Getting two closely spaced APXS targets makes it easier to pull apart compositional variations within the outcrop than a single APXS analysis alone. We planned a ChemCam raster over Fern Spring to be able to compare the compositional results from APXS and ChemCam, and a second, similar target, "Redfield Hill" to maximize the amount of data from the bedrock. Another target that got attention from both APXS and ChemCam was "Pulpit Ledge", so named because this gray-toned area of outcrop appeared perched above the rest of the outcrop surface. The gray color of Pulpit Ledge set it apart from the more orange-red color of Fern Spring and Redfield Hill, and the science team hoped to gain insight into why these parts of the outcrop were different in color by looking at these distinct targets. We looked at another gray outcrop area, "Broad Cove", using the passive mode of ChemCam and the multispectral capability of Mastcam. Both these techniques assess the spectrum of light reflected from the target surface, which provides insight into the iron mineralogy of the target. Each APXS target was imaged with MAHLI, to not only help inform APXS of exactly what part of the outcrop they obtained data from, but to look closely at the texture and grain size of the targets. Looking out past the outcrop immediately in front of us, Mastcam acquired small mosaics of two separate areas of dramatically layered Murray formation. Such large, layered blocks make driving through this part of the Murray formation a challenge, but they help the science team understand how the Murray formation rocks were deposited in Gale crater.

Curiosity cast her gaze skyward over the weekend acquiring images and movies seeking clouds and dust devils, and monitoring the amount of dust in the atmosphere. Measurements of dust in the atmosphere not only provide insight into atmospheric behavior, they help the science team decide when to image distant objects such as Vera Rubin Ridge. The more dust in the atmosphere, the harder it is to see such objects. The rover also prepared for an important upcoming atmospheric analysis, a SAM measurement of atmospheric methane.

Sols 1705 - 1706 update by Abigail Fraeman: Rocky Road (May 22, 2017)

Curiosity is continuing to make progress towards Vera Rubin Ridge along the Mt Sharp ascent route. We planned two sols today, Sol 1705 and Sol 1706. On our first sol, we will kick off the day with some remote sensing science on the bedrock in front of us, including ChemCam observations of targets "Turtle Island", "Stony Brook", and "Dike Peak". Turtle Island is typical Murray bedrock, Stony Brook has an interesting dark streak running through it, and Dike Peak is a neat looking block with dark colored fracture fills. We will complement these observations with Mastcam documentation imaging. We’ll then go for a short drive and take some post drive imaging and a ChemCam AEGIS observation. On the second sol of the plan, Curiosity will be focused on taking atmospheric observations, including a dust devil search and images of the crater rim and sky above us.

We didn’t drive as far as we thought we would over the weekend. Software onboard Curiosity sensed the rover was struggling to travel over the challenging terrain more than we had anticipated, so it ended the drive early. Because I was staffed as a Surface Properties Scientist (SPS) during planning today, I spent most of my time on shift looking at the Navcam and Hazcam data to understand what about the terrain was causing problems, and thinking about new paths to take that would still get us where we wanted to go. I’m optimistic about our new drive route, and I’m very glad we have six-wheel drive to help us climb this mountain!

Sols 1707-1708 update by Michael Battalio: When Mars Gives You Lemons, Calibrate Your Instruments (May 25, 2017)

After a 14.6 m drive, the GEO group decided against arm activities due to a lack of compelling targets and in deference to making the next drive longer. Thusly, GEO science activities relied on Mastcam and ChemCam. On Sol 1707, ChemCam will capture a raster of the "White Cap Mountain" bedrock target (the white bedrock left of center in the bottom quarter of the above Navcam image), as well as a patch of dark undisturbed soil called "French Hill Pond." Mastcam will document all of the ChemCam targets and will image "Googings Ledge" (the large, darker bedrock just above and right of image center) and "The Twinnies" (the shadowed bedrock exposure cut off on the far left), which are sedimentary members of the Murray formation, and "Soward Island," which has exposed bedrock layers. After a planned 30 m drive, ChemCam will perform an AEGIS automated activity, and Navcam will document Curiosity's new position. SAM will perform a methane dual enrichment activity on Sol 1709, which will compare a methane-enriched atmospheric sample to a non-enriched sample.

I served in the ENV STL role, and today was one of the more hectic ENV operations days I have planned. It was a plan full of trade-offs. When SAM takes atmospheric methane or oxygen measurements, ENV likes to obtain a ChemCam passive sky observation within a few sols for an independent comparison. However, the times initially available in the plan around mid-sol to place a passive sky were not compatible with possible pointing azimuths, as we are so close to the new year (northern hemisphere spring equinox). In anticipation of potential power restrictions in the weekend plan, we attempted a long morning imaging suite a couple of sols early, which would include a passive sky measurement; however, we were forced to defer those plans due to power restrictions in the current plan. Instead of losing the science time altogether, we noticed that the mid-sol time was compatible for taking a ChemCam calibration measurement. This calibration will be taken on Sol 1708 in preparation for the next passive sky. This just proves that while doing science on another planet can be frustrating at times, it is always rewarding.

On top of the ChemCam calibration, the ENV group planned several Mastcam and Navcam observations. On Sol 1707, Mastcam will capture tau and LOS measurements to assess the amount of dust in the atmosphere. Also on Sol 1707, Navcam will capture a late afternoon zenith cloud movie. A 30-minute Navcam dust devil movie will be taken around noon on Sol 1708. REMS will capture the standard top of the hour 5 minute observations and 19 hour-long observation blocks, which will include observations during the ingest times of the SAM methane activity. DAN will take approximately 9 hours of passive and 20 minutes of post-drive active observations.

Sols 1709-1711 update by Roger Wiens: "White Ledge" (May 26, 2017)

Curiosity continues to drive through an otherworldly jumble of in-place bedrock, tilted rocks, sand with small ripples, and local pebbly debris piles. Vera Rubin Ridge continues to loom larger in the rover’s forward view, although progress is somewhat slow due to the difficult terrain. Yestersol’s drive was 16 meters.

Just 20 sols ago we passed the northern vernal equinox, but the rover is ‘down under’ (at 4 degrees south latitude), so we’ve just started the fall season. For those readers in the Earth’s northern hemisphere, it’s like about October 1 on Earth. Over the next half of a Mars year (or nearly one Earth year) the rover will have a little less power for driving, arm deployment, and instrument activities as it spends a little more energy keeping itself warm. The body of the rover is kept warm by a fluid loop that distributes heat from the radioisotope thermoelectric generator (RTG) to the rover body, but the extremities (arm, wheels, and mast) need to be heated electrically. As a result, the rover will take one day to recharge its battery this weekend. It’s a holiday weekend in the US and much of Europe, so why shouldn’t Curiosity have a day off too?

We also have a soliday, but that’s not a rover holiday, in fact, it’s not a day on Mars at all. Rather, it’s an extra day we have on Earth every 37 Mars days due to the shorter day on Earth. So Mars has one less day for this holiday weekend. All told, the rover will be working two days this weekend.

As I write today’s Mars blog post, we are finishing the science operations working group (SOWG) meeting, arranging the plan. We have a beautiful "White Ledge" right in front of the rover, and so we decided to spend these two Mars days doing lots of analyses. We are interrogating the ledge with two different arm placements, an evening APXS integration on a location named "Patty Lot Hill," and a night integration on "White Ledge" after using the dust removal tool (DRT). MAHLI takes images of these targets the following sol. We are taking extra precautions in case the rather thin ledge breaks when we place the arm on it. We are also interrogating the ledge with Mastcam and ChemCam. Other ChemCam targets include "Shooting Ledge" (a rocky ridge just behind "White Ledge"), "Middle Ledge" behind and to the left, and "Halfway_Mountain", a sand ripple crest. SAM is doing an atmospheric measurement, and REMS and RAD are taking measurements this weekend too, so it is an "all-instruments" weekend except for CheMin.

At the end of the second sol Curiosity drives to a good vantage point (< 20 m). We also managed to slip in Mastcam sun observations and a ChemCam sky spectral observation on Tuesday morning (Sol 1712) before the next uplink of activities from Earth.

Sol 1712 update by Michelle Minitti: Eyes on the prize (May 30, 2017)

Despite the holiday weekend, the science and engineering teams were greeted with a plethora of data from Curiosity when they started planning Sol 1712 - like your birthday and your favorite winter (gift-getting) holiday rolled into one. The science team had beautifully illuminated MAHLI images of the unique texture of our weekend targets "White Ledge" and "Patty Lot Hill," loads of ChemCam and APXS data from rocks and soils, and new atmospheric measurements courtesy of SAM, ChemCam, Navcam and Mastcam. The engineers had new drill diagnostic data, which will help them learn ways to get the drill back in use. Getting to put Curiosity right back to work after receiving such an embarrassment of riches makes for one grateful team.

The bedrock in front of the rover resembled the Murray formation bedrock we have seen over the last week or so, so the science team did not feel the need to acquire MAHLI and APXS on it before driving away. Instead, the team eyed an outcrop of gray toned, layered rock about 10 m to the south.

We have seen this type of gray-toned rock before, which differs in chemistry and texture from the Murray formation, but have had little luck accessing it for contact science. To further understand how and why this outcrop differs from the Murray, the team asked the rover planners to drive us to the outcrop for a touch-and-go on it with MAHLI and APXS in the plan tomorrow. While the rover planners could have driven to a point ~15 m past the gray outcrop, the team felt the opportunity to reach out and touch this rock was worth driving a little bit less than was possible today. We will all have our fingers crossed for a successful drive!

Before heading down the road, we acquired ChemCam data from two targets, "Ned Island" and "Ravens Nest," both of which will add to our Murray formation dataset as we climb Mt. Sharp. We kept tabs on the dynamic environment around us by acquiring REMS and RAD measurements, Mastcam images of dust in the atmosphere, and Mastcam images of changes in sand blown onto the rover deck. All told, it was a successful start to what should be another great week in Gale Crater!

Sol 1713 update by Abigail Fraeman: Not enough hours in the sol (May 31, 2017)

Tosol on Mars was one of those sols where we simply did not have enough hours to get everything done that we had wanted to do. Our Tuesday drive placed us perfectly in front of a very interesting outcrop that looked slightly different in color and texture from the typical Murray rocks we’ve been seeing for the last few hundred meters. We had originally thought we would spend the morning doing contact science on this outcrop and then drive away in the afternoon, completing everything before the Mars Reconnaissance Orbiter flew overhead and it would be time to call home. However, when the downlink came in this morning, the science team found there was a lot we wanted to look at that was accessible in our workspace. The rover drivers also reported that the route ahead was clear and we would be able to do a nice long drive. With all of these options but a limited amount of time available before the orbital pass, we concluded it would be best to plan to spend all of the sol doing science on the outcrop, and then wait until tomorrow to drive away.

The geology theme group certainly took advantage of the unexpected extra time for science, and filled the plan with lots of remote sensing and contact science activities. We planned to take APXS observations of two targets on gray-toned rock targets named "Berry Cove" and "Heron Island," as well as MAHLI observations of both of these targets plus an additional target at the contact between a red and gray rock named "Prays Brook." We’ll complement all that with ChemCam observations of gray rock targets named "Spectacle Island," "McNeil Point," and Heron Island, plus associated Mastcam imaging to support the ChemCam observations. We’ll also be getting even more Mastcam images of interesting surrounding rock targets "The Whitecap," "Trap Rock," and "Pond Island," and a ChemCam remote micro-imager (RMI) mosaic of target "Sols Cliff." Finally, we’ll also be doing our standard background REMS and DAN passive observations to monitor the environment. Whew! It should be a great day of doing science on Mars.

Sol 1714 update by Lauren Edgar: Let's try that again (June 1, 2017)

Unfortunately the Sol 1713 activities were not uplinked due to an issue at the DSN station, so today's plan is focused on recovering the activities that were planned yesterday. The good news is that we’ll be in the same location for the start of the weekend plan, so we’ll be able to add some additional contact science targets at this interesting site.

I was the SOWG Chair today, and it was a pretty straightforward planning day since it was mostly a repeat of yesterday! The plan kicks off with Mastcam mosaics of "The Whitecap," "Trap Rock," and "Pond Island" to document some nearby sedimentary structures. Then ChemCam will target "Heron Island" and "McNeil Point" to investigate variations in chemistry within the darker gray rocks in this area. We’ll also acquire a ChemCam RMI to assess the grain size and stratification at "Sols Cliff." Then Navcam will carry out a dust devil survey to monitor atmospheric activity. Slightly later in the afternoon, we’ll acquire a Mastcam mosaic to document the contact science target "Prays Brook" and surrounding rocks, and we’ll take a multispectral observation on "Heron Island." The meat of the plan lies in the contact science: APXS and MAHLI observations on "Berry Cove" and "Heron Island" to assess the darker gray rocks both with and without nodules, as well as a dog’s eye MAHLI mosaic along "Prays Brook" to characterize the contact between the dark gray rocks and the underlying typical Murray formation. It’s a juicy plan so I hope it all goes smoothly this time, and we’re looking forward to more contact science tomorrow before we hit the road to Vera Rubin Ridge.

For more information about Curiosity’s investigation of the Murray formation and the ancient lake environments that it records, check out this recent press release.

Sols 1715-1717 update by Michelle Minitti: If it's worth doing, it's worth doing right (June 5, 2017)

Curiosity left no stone unturned, unshot or unbrushed as she wrapped up observations at the stand of gray-toned rocks she arrived at on Sol 1712. We added to yesterday's rich observations of gray-toned rocks by brushing a nodule-rich target, "Timber Point," to give MAHLI and APXS as clear a look as possible of the target's texture and chemistry. We added to yesterday's rich observations of gray-toned rocks by brushing a nodule-rich target, "Timber Point," to give MAHLI and APXS as clear a look as possible of the target's texture and chemistry. Scattered amongst the gray-toned rocks were patches of Murray formation rocks, and the team thought it best not to neglect our old friend. MAHLI images and APXS data from the Murray target "Old Mill Brook" will complement all the data we have collected from the gray-toned rocks. Both Timber Point and Old Mill Brook were also accessible to ChemCam, which will shoot both these targets before MAHLI has a look at them. This gives MAHLI a unique chance to look at the laser-disturbed material within each ChemCam spot, which can reveal more about the grain structure of the target than an observation of an undisturbed surface. ChemCam also analyzed a second Murray target, "Goose Eye Mountain," to expand our dataset on this material, and a beautifully-layered, gray-toned target called "Spectacle Island." We accomplished most of our Mastcam imaging of the outcrops around us yesterday, but additional Mastcam imaging of Spectacle Island was just too good to pass up.

Curiosity will also acquire a variety of images and movies of the skies. Taken in the early morning and later in the afternoon, they will help us understand the dynamics of the atmosphere over the course of the Martian day. SAM will prep for its next atmosphere measurement, as well.

After all this activity, Curiosity will drive away from our gray rock playground, for new discoveries uphill!

Sols 1718 update by Scott Guzewich: Looking East (June 5, 2017)

We are beginning to turn toward the east and southeast as we approach Vera Rubin Ridge with the Curiosity rover. After a busy and successful plan over the weekend, we weighed our priorities between using APXS to study the bedrock we're driving over or drive farther along our path.

Today I was the Science Operations Working Group Chair as we planned sol 1718 and since we had only gained ~3m of elevation in our last drive, we decided to forgo contact science with APXS in favor of extending our drive distance. The GEO science theme group still found some interesting bedrock-"East Point" (the dark section in the middle of the rock at the upper right corner of the image), "East Pond", and "Eastern Point Harbor" - to target with ChemCam and Mastcam before we begin our drive. After a ~26 meter drive, we planned post-drive imaging to prepare for the next sol's activities and conducted a ChemCam AEGIS activity. The ENV science theme group had a quiet plan with routine DAN and REMS observations.

Sol 1719 update by Ryan Anderson: Wait and Hurry Up! (June 6, 2017)

Today was an interesting day of planning: because of an issue with the computer system responsible for processing data once it is received on Earth, Curiosity's images and other data from Sol 1718 didn't arrive until well into today's planning. That meant that we had to keep the plan simple and respond rapidly once the data did arrive. It also meant that we had plenty of time to choose our favorite target names from the list!

Once the data started rolling in, we quickly chose a nice piece of bedrock in front of the rover for APXS and MAHLI to analyze and gave it the target name "Aunt Betsey's Brook". We also planned a ChemCam observation of a flaky layered rock called "Wonsqueak Harbor" and a small Mastcam mosaic of a block of layered bedrock called "Little Round Pond". After that, Curiosity will drive about 16 meters and collect post-drive imaging for targeting. After the drive we'll also take a Mastcam image of the ground near the rover (part of the ongoing campaign to systematically look at the terrain we're driving over), Mastcam images of the sun and the distant crater rim to study dust in the atmosphere, and an automatically targeted ChemCam observation. The plan will wrap up with the usual evening MARDI image of the ground under our wheels.

In the end, despite the delay in planning, we managed to put together the plan and turn it in early! We joked that we can't keep being so efficient every day or else we'll give the impression that we don't need our full planning time anymore!

Sol 1720 update by Christopher Edwards: Rough Road Ahead (June 8, 2017)

I was the Surface Properties Scientist, or SPS on staff today. The SPS has an interesting job, in that the SPS helps Rover Planners (called RPs) assess the terrain around the rover with safety in mind, first and foremost.

There are two main jobs of an SPS. The first is to assess how likely the rover is to slip in its current position, called the Slip Risk Assessment Process (SRAP). Is it on a stable footing, like thin sand cover over smooth rocks, or is a wheel perched on a ledge? The reason this is important is because as MSL's arm is articulated to conduct contact science, a perched rover wheel might slip and cause damage to the arm by contact between the turret and the ground. That would be bad! Today we were on a solid surface and passed SRAP without any concerns.

The other job of the SPS is to help the RPs find a safe path forward if there is a drive planned. On some sols this is a very taxing job, other days not so much. Today was in the middle. The RPs use high resolution digital terrain models generated from imagery taken from the previous sol after the latest drive to plan a safe path to the next stopping point, while avoiding rocks, ledges, and deep sand. The RPs confer with the SPS to evaluate the proposed route making any modifications necessary along the way. Today, the path directly ahead was pretty rough, so the drive was planned to dodge some angled rocks, and head back towards the Mount Sharp Ascent Route and ultimately the Vera Rubin Ridge.

Sol 1721 update by Ken Herkenhoff: An easier planning day (June 8, 2017)

MSL drove 26 meters on Sol 1720, as planned, to a location with blocks of bedrock in the arm workspace. Because the rover climbed another 3 meters in elevation, contact science has top priority for today's plan, with driving next in priority. One of our strategic goals is to measure the chemistry of Murray formation rocks using APXS at elevation intervals of no more than 5 meters. So the GEO science theme group (STG) selected a smooth, typical Murray bedrock target named "Fawn Pond" as the top priority for contact science (APXS and MAHLI observations), and planned ChemCam and Right Mastcam observations of nearby target "Kief Pond." The GEO plan also includes a 6x2 Right Mastcam mosaic to investigate sedimentary structures at "Arey Cove" and standard post-drive imaging.

The ENV STG requested non-standard RAD activities that required lengthening the post-drive science block. Despite concerns about power, all of these science activities fit nicely into the plan! I'm SOWG Chair today for the third day in a row, and it's been the easiest shift so far: There were no delays in processing the new data needed for planning this morning, and the volume of data expected to be returned in time for planning tomorrow is comfortably larger that it was on Sols 1719 and 1720.

Sols 1722-1724 update by Scott Guzewich: Leftovers for Dinner (June 9, 2017)

Today, as I served as the Science Operations Working Group Chair, we prepared a 3-sol duration plan to keep Curiosity busy over the weekend. Almost the entirety of the first two sols (1722 and 1723) are dedicated to a SAM analysis of a "doggy bagged" sample from the Quela drill hole collected back in September 2016 (Sol 1464). Several times in the mission we’ve saved samples from our drill locations to analyze later. This SAM analysis will help us determine the precise chemical composition of the martian bedrock and therefore improve our understanding of ancient martian history!

On the third sol of our plan (1724) we planned ChemCam and Mastcam observations of a bedrock target termed "Old_Point" (the flat light-toned rock just below the ripples in the image to the right). ENV also scheduled an early morning science block on Sol 1725 before we begin that sol’s plan. These morning activities help us understand how atmospheric conditions change at different times of day, for example, how the clouds and dust in the atmosphere vary between morning and afternoon.

Sol 1725 update by Michelle Minitti: Curiosity's four day weekend (June 12, 2017)

On most weekends, Curiosity dedicates part of her efforts to do contact science - deployment of APXS, MAHLI, and sometimes the DRT - because multi-sol weekend plans have more time and power to fit in these more complex activities. Last weekend, however, time and power were dedicated to a more rare, and more complex, activity - analysis of a previously-drilled rock sample by SAM. To keep up our regular cadence of contact science, the team effectively extended the weekend by a day, planning contact science in this Monday plan. The workspace in front of the rover did not disappoint, with no shortage of options on a nice slab of Murray formation bedrock to reach out and touch!

The team selected a trifecta of targets for MAHLI and APXS, each with its own unique characteristic. "Haynes Point" is located on red-toned Murray, "John Small Cove" is located on tan-toned Murray, and "Barr Hill" is located on flat-lying white vein material coating parts of the workspace bedrock. The mast instruments also got in on the action, with ChemCam shooting both Haynes Point and Barr Hill, and Mastcam acquiring a multispectral observation that covered all three contact science targets. Planning such complementary observations with multiple instruments helps the team extend their understanding of the rocks interrogated by the rover. After starting off Sol 1725 with an early morning suite of environmental observations, only a few additional sky observations were acquired in the rest of the plan along with regular REMS and RAD measurements. Curiosity will get back on the road tomorrow, driving ever closer to the spectacular topography of the Vera Rubin Ridge.