Tag: Curiosity

For the third time Curiosity has failed to drill into the rock on top of Vera Rubin Ridge.

Last night we learned that our drill attempt on “Inverness” was not successful, reaching only 4 mm into the rock.

The only successful drill attempt on the ridge occurred when they moved down off the top of the ridge to a slightly lower geological layer.

They are moving Curiosity to another candidate drill site on the ridge, where they will try again. While they imply in their reports that it is solely the hardness of the ground that is stopping them, I still wonder if the improvised drill technique, using the robot arm to push down rather than the drill’s jammed feed mechanism, is partly to blame. I would think that they have placed limits on how hard the arm can push to protect it.

Before they will resume the journey up Mount Sharp the Curiosity science team now plans two more drilling attempts on Vera Rubin Ridge.

The rover has never encountered a place with so much variation in color and texture, according to Ashwin Vasavada, Curiosity’s project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. JPL leads the Mars Science Laboratory mission that Curiosity is a part of.

“The ridge isn’t this monolithic thing — it has two distinct sections, each of which has a variety of colors,” Vasavada said. “Some are visible to the eye and even more show up when we look in near-infrared, just beyond what our eyes can see. Some seem related to how hard the rocks are.”

Part of this drilling campaign will also include gaining a better understanding better their improvised drilling technique.

Link here. They very much wanted drill samples on Vera Rubin Ridge, but had twice found the rock too hard for Curiosity’s drill. So how did they pinpoint the spot, dubbed Stoer, where the drill finally worked?

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.

The successful drill hole, Stoer, was thus down somewhat from to top of the ridge. As they prepare to move on, it appears they want to try again to drill at the top of the ridge. It also appears that the work described above has maybe found another location there where the rock might be soft enough for the drill.

Curiosity has finally drilled its first successful hole in the geology layer found on Vera Rubin Ridge.

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.

In order to find rock soft enough on Vera Rubin Ridge, they had to once again retrace their route, retreating back down off the ridge slightly, to a lower point. The image on the right, cropped to post here, shows the drill hole. If you click on the image you can see the full picture.

With this successful drilling, I suspect they will now finally cross Vera Rubin Ridge and head up Mount Sharp.

It appears that, after a descent down off of Vera Rubin Ridge and then spending 30 sols sitting at one spot to do its first drilling in more than a year, Curiosity is about to resume travel up Mount Sharp.

With its newly resurrected drilling capabilities, Curiosity will do one last pass over the Vera Rubin Ridge units, now that the rest of the instrument suite onboard can have access to this and future drill samples.

It appears they will be returning to their planned route, across the ridge and down off it to head up towards one known recurring black streak that might be a seep of underground water.

They have not provided any details about the lab results from the drill sample, but that isn’t surprising. It will take some time to analyze it, and the scientists involved will want the glory of publishing their results once that analysis is complete. What is clear from the update is that the drilling worked, and that this particular drillhole is likely to produce some of the more significant findings from Curiosity.

In a study released today, the Curiosity science team announced that earlier drill samples revealed evidence of complex organic carbon molecules, the possible remains of past life.

To unlock organic molecules from the samples, the oven baked them to temperatures of between 600°C and 860°C—the range where a known contaminant disappeared—and fed the resulting fumes to a mass spectrometer, which can identify molecules by weight. The team picked up a welter of closely related organic signals reflecting dozens or hundreds of types of small carbon molecules, probably short rings and strands called aromatics and aliphatics, respectively. Only a few of the organic molecules, sulfur-bearing carbon rings called thiophenes, were abundant enough to be detected directly, Eigenbrode says.

The mass patterns looked like those generated on Earth by kerogen, a goopy fossil fuel building block that is found in rocks such as oil shale—a result the team tested by baking and breaking organic molecules in identical instruments on Earth, at Goddard. Kerogen is sometimes found with sulfur, which helps preserve it across billions of years; the Curiosity scientists think the sulfur compounds in their samples also explain the longevity of the Mars compounds.

Earth’s kerogen was formed when geologic forces compressed the ancient remains of algae and similar critters. It’s impossible to say whether ancient life explains the martian organics, however. Carbon-rich meteorites contain kerogenlike compounds, and constantly rain down on Mars. Or reactions driven by Mars’s ancient volcanoes could have formed the compounds from primordial carbon dioxide. Monica Grady, a planetary scientist at The Open University in Milton Keynes, U.K., believes the compounds somehow formed on Mars because she thinks it’s highly unlikely that the rover dug into a site where an ancient meteorite fell. She also notes that the signal was found at the base of an ancient lake, a potential catchment for life’s remains. “I suspect it’s geological. I hope it’s biological,” she says.

It must be emphasized once again that they have not found evidence of past life. What they have found are the types of molecules that are often left behind by life, but can also form without the presence of life.

This result, from past drillholes in the Murray Formation, explains however why Curiosity headed back downhill to do its most recent drill test.

Curiosity has one last tool to help the team find out: nine small cups containing a solvent that frees organic compounds bonded in rock, eliminating the need to break them apart—and potentially destroy them—at high temperatures. In December 2016, rover scientists were finally prepared to use one of the cups, but just then the mechanism to extend the rover’s drill stopped working reliably. The rover began exploring an iron-rich ridge, leaving the mudstone behind. In April, after engineers found a way to fix the drill problem, the team made the rare call to go backward, driving back down the ridge to the mudstone to drill its first sample in a year and half. If the oven and mass spectrometer reveal signs of organics in the sample, the team is likely to use a cup. “It’s getting so close I can taste it,” says Ashwin Vasavada, Curiosity’s project scientist at the Jet Propulsion Laboratory in Pasadena, California.

The newest drillhole sample has now entered the mass spectrometer. Stay tuned!

In order to bypass a failed feed mechanism in the rover’s drill, Curiosity’s engineering team has declared successful the new techniques they have developed for drilling and getting samples.

They had successfully completed a new drill hole two weeks ago, but are only now are satisfied that the new method for depositing samples in the laboratories will work.

This delivery method had already been successfully tested at JPL. But that’s here on Earth; on Mars, the thin, dry atmosphere provides very different conditions for powder falling out of the drill. “On Mars we have to try and estimate visually whether this is working, just by looking at images of how much powder falls out,” said John Michael Moorokian of JPL, the engineer who led development of the new sample delivery method. “We’re talking about as little as half a baby aspirin worth of sample.”

Too little powder, and the laboratories can’t provide accurate analyses. Too much, and it could overfill the instruments, clogging parts or contaminating future measurements. A successful test of the delivery method on May 22 led to even further improvements in the delivery technique.

Part of the challenge is that Curiosity’s drill is now permanently extended. That new configuration no longer gives it access to a special device that sieves and portions drilled samples in precise amounts. That device, called the Collection and Handling for In-Situ Martian Rock Analysis (CHIMRA), played an important role in delivering measured portions of sample to the laboratories inside the rover.

I suspect that they still need to do more tests, and that the new method of shaking off material from the drill itself will not always work. At the same time, it reopens the option of using the drill and getting samples from it, which is a very good thing.