Does anyone know if there are any preliminary results from the RISE experiment?

P

a quick recap of InSight's first scientific results on today's Nature

‘Marsquakes’ reveal red planet’s hidden geology

I think I read somewhere that the first papers were going to be published this week in Science (or Nature) but I'm not sure

“…but that they expected InSight’s landing place to have cohesionless soils because that’s what other Martian landing sites have been like.
InSight seems to have been unlucky enough to land in a place where the soil is compacted into a harder material called a duricrust,…”
What would have happened if they had landed at VL or VL2 landing sites, with high soil cohesion ?
Click to view attachment <== VL1 / VL2 ==> Click to view attachment

Last hammer session of the year on sol 380

Animated IDC GIF: indicates a slowing of progress as the session progressed, then a minuscule bounce? before a little more downward progress? Hopefully a few more images in the pipeline

Click to view attachment

^COOL!


Can you combine it with last clip?

Here you go.... link

Almost as if it is running into something hard.

The team mentioned a hard duricrust layer, I'm not sure if they know how thick that layer is, but progress of the mole slowed at this depth last time. Fingers crossed it's almost through that harder layer...

The DLR HP3 blog for the mole has been updated (December 23, 2019)

Link

As the update explains, it seems that the cohesionless sand below the duricrust is the problem. They need friction to make progress.

not much going on mole-wise, so looking for environmental subtleties, here's ten frames from 14 sols: 383//385//387/388/389/390/391///394/395/396 all are taken at within one second of each other 15:53:49 to highlight any wind effects as well as some unexpectedly noticeable seasonal illumination changes.
Click to view attachment

Seems like the scoop is getting a bit dusty?

pretty much all was deposited between sol383 and sol385 must have been a particularly windy sol to have kicked up that much, but unfortunately the date range has cycled out (where to find full data?) so cant tell if those sols had anything above the normal max gusts...

Hammer attempt? Sol 400 Scoop movement, but I don't see any obvious movement by the mole.

Processed frames used to assemble this animated GIF using the three frames where there was movement. I guess other frames maybe in the pipeline?

Click to view attachment

Putting more pressure on the mole at this stage, I think, with a hammer to follow.

Phil

and back up again : (

This time they got some imagery of the mole coming back up while the mole's unintended ascent was happening. That may not lead to a solution but at least it's more informative than hammering for a long time and then seeing that it backed far out of the hole.

Such frustrating antics, seems to just be jumping atop the infill it dislodges by hammering, that soil behavior might not be any different even if it were able to get a dozen or more centimeters deeper, so what now? Since the arm pressure cant follow as the mole and pit conditions change, they might be able to instead just go about it very slowly, repositioning the arm after even very small hammering sequences, who knows..
Here's a gif of that sol407 sequence:
Click to view attachment

Frustrating as hell to be sure, but in the long run instructive. Figuring out exactly why something didn't work that should have is always useful.

Apart from the problem with the heat flow instrument, another casualty of the current situation is the lack of a full panoramic image of the landing site. The arm can't point its camera around the site to image it while it is staring at the ground. There were plans for full panoramas with different lighting conditions, but they must be on hold.

However, lots of images have been taken, certainly a full horizon panorama which has been reported here already. Has anyone gone beyond the basic horizon panorama to extend it into the workspace?

Phil

Hmm, not sure if I asked this before but-

1) What is the maximum downward force that the arm can generate?
Both continuous (push) or and impulse (punch)?

2) How deep a hole CAN the arm dig?

3) How far down is the caliche / duricrust layer estimated to be?
Any data about delta-T and the quantify heat loss, that might suggest regolith depth, which might imply duricrust depth?

I'm figuring this is the "Andy Dufresne" segment of the mission...
"All it takes is pressure, and time"...

Hi,

I don't wish to sound rude but that smacks of repeating the same thing over and over ...etc

Currently the mole is next to useless, so personally I would give it until the end of the month then attempt to put the arm under the tether close to the mole and try to lift it up then reposition.

It might work/might not, suppose it depends on how high the arm can go and which is heavier, the mole or the tether, can't be any worse than now though.

I know it's a bit left field but heh, as Delboy said many times "He who dares wins Rodney, he who dares wins"

Initially the team believed that the obstruction causing the mole to bounce back out of the ground could not be a buried rock because there were so few rocks on the surface and these were small. However the rock excavated by the lander exhaust exhaust as illustrated below raises a few doubts. The mole was designed to veer around a small obstruction but if it encountered a buried rock of similar size and shape this would explain the current angle of attack and repeated bounce back. Perhaps moving the mole as Algorithm suggests would be high risk and aligning it vertically and keeping it stable for initial penetration without damaging the ribbon would seem near impossible. But the current approach is not achieving much and who dares wins. (sometimes).

That's ok, not rude at all -
But I'm suggesting that it may be time to begin a stress-strain-cohesion analysis of the surface crust, subsurface rocks and deeper "duricrust". Dig a few sample holes at different depths, sift out the contents into piles to check the cohesion/angle of repose. Compress the sample piles with the bucket to get some actual values for the material at the site. Then, act based on the evidence gathered.

After doing some soil horizon analysis, proceed with "Operation-Archie" ("Red Dwarf-Kryten Reference)
Let the mole back itself all the way out of the dry-hole and tip over horizontal.
Use the arm to dig a new hole, and pile up the hole tailings to make 2 guide berms leading to the new hole.
Let the mole skitter over and tip into the new hole.

From what we've heard from the team, the behaviour so far is consistent with bouncing back due to lack of friction, not hitting a rock. The crucial question is: can pressure be applied by the scoop until the mole gets deep enough that it can "get a grip" on its own?

I see it as a question of "long term" versus "short term."

Short term - outcome orientated: how do we get the mole to work in this soil.
Long term - observation orientated: how much DON'T we know about martian soils?

Smacking and scratching the soil around Insight is basic research How variable IS martian soil?
At what SCALE do the properties (grain size/cohesion/cementign) change?
Is the soil variable at a scale of decimeters, meters?

I guess they have been doing an awful lot of testing with Mars analogue regolith and the pressure from the scoop initially worked well. The thing that intrigues me is the sudden reversal of the mole while pressure is being applied by the scoop and the inclination of the mole which initially seemed consistent with am attempt to bypass an obstruction.

I thought what was happening was that as the mole dug in during the hammering, at some point the mole had changed position/orientation just enough that the scoop was no longer snug enough against it to apply enough pressure to keep it digging. Basically as the mole dug the force of the scoop was nudging the mole away from the scoop until the scoop could no longer apply enough force.

Could well be, although Atomoid's gif (Post #818) seems to indicate that the pressure remained on the mole.

According to the last post on the team blog (which has frequent caveats to indicate guesses rather than certain knowledge), the duricrust is about 20 cm thick, and the problem is that it is underlain by cohesionless soil. When the mole reaches the cohesionless layer below the duricrust, it pops back up. If it's all as simple as that, then we're at a futile impasse.

The scenery and my understanding of it is that, with the exception of pebbles, this area is isotropic – there are no important differences if you move 10 cm, 1 m, or several meters in any direction.

It sounds pretty hopeless. Of course, there's no great motive to stop trying, so I expect the team to keep trying until the last days that the lander continues to function, but nothing suggests a plausible path to success unless their interpretation of the situation is unexpectedly pessimistic.

Unless the arm can dig through the cohesionless layer, or dump cohesive soil into the existing hole.
Consider a 5 gallon bucket filled with marbles - basically cohesionless. Same for a 5 gallon bucket filled with dry rounded beach sand - basically cohesionless. However, MIX the two, and they have plenty of cohesion.




If ~20 cm vertically makes a huge difference in soil properties, why assume there are no differences at any horizontal scale?
https://permafrost.gi.alaska.edu/

Vertical diversity and horizontal diversity are not intrinsically related. A pond with 2 cm of ice over 1 m of water over smooth mud may have tremendous vertical diversity and virtually none horizontally.

The Mars Insight landing site was chosen with the goal of it being boring. Of course many places on Earth and Mars are not, but this one appears to be.

Is that certain? No. And as options fail, they may have little to lose by hoping to find some anisotropies lurking down there. But nothing from the team or the visual appearances suggest any.

I didn't look too much into Phoenix but i think the scoop design may have been different since trenching wasnt a part of the mission, however it may be similar enough that some trenching may be possible, Phoenix apparently able to dug a 18 cm deep trench when checking out the polygons, though i dont know what its maximum reach may have been, physically, as it seems it was thwarted by impassable icy soils. Similar attempts by Insight may be able to do better if the deployment arm dynamics are similar enough, but of course i like guessing.

With incrementally readjusted arm pressure per percussion sequence, the back of the mole should eventually reach level with the surface, at which point it will be necessary to very carefully place the end of the scoop on a portion of the mole end-cap in either a flat or pointed configuration to prevent it from backing out again.
In an edge-on configuration it may be possible to drive the end-cap a few cm below soil level where soil can be mounded atop the hole in order to fill the hole as it digs, keeping some pressure atop a portion of the soil mound to encourage infill all the while allowing as free threading of the ribbon as possible, as it seems the only source of friction below surface for a while is going to be in the form of back-filled soils jamming up its backup antics, with those first few cm as critical, once the back of the mole gets deep enough, the increase in friction from the increasing infill should exceed the bounce-back effect, redirecting that energy to digging again, unless it somehow pounds out a hollow sheath within which it will eternally ping-pong... so as usual much easier said than done.

I have a very simple question to which some here may know the answer while others following may not. What is the mean density of the mole and how does it compare with the surrounding soil?

The density of the regolith at the immediate sub surface or deeper is unknown. The mean density of the mole is not really germane to its operation which delivers hammering energy of some 0.83 J every 3 seconds. In effect the mole is a self powered cone penetrator. The link provides some data on the anticipated performance of the mole modeled to scale for Mars gravity. The thing is the model output table addresses cohesionless soil (sand, dust) so the determination that the mole failure was due to encountering cohesionless regolith is a tad surprising and is why I considered an encounter with a rock a reasonable possibility. I guess that despite landers and rovers we have hardly scratched the surface of Mars and our knowledge of the properties of what lies below is akin to the old map makers. "Here be dragons".

https://www.researchgate.net/publication/26...nSight_HP3_Mole

Both Insight and phoenix have arms from the 01 surveyor program and is very identical to the one used on Mars Polar Lander, though with slight design differences in the scoops between the three and some differences in the arm camera's. The arm though is capable, as mention in this of digging a 1.6 foot (0.5m) trench if soil properties allowed it to do so and another factor is the distance of trenching from the lander. The only reason why Phoenix couldn't get that deep is because of the ice layer of coarse. Going that deep, I would think the regolith would have to have some good cohesion to help with walls from caving in as well. Also noted, the Mars Polar Lander arm was tested in death valley and produced a 10 inch deep trench in under 4 hours. I would expect similar performance with Insight's arm, though with the smaller scoop it just would take a little longer. Another thing to keep in mind is the weight of the grapple because having that extended out will lower the digging force that the arm could apply when the arm is reached fully out and also clearance that it would have with the ground when digging a deep trench.

https://www.nasa.gov/mission_pages/phoenix/...obotic-arm.html

Insight's IDS is in fact the MSP 01 lander's, refurbished: http://esmats.eu/esmatspapers/pastpapers/p.../fleischner.pdf

Phoenix used a modified version of this arm (if they could have used the original one, I assume they would have) but I wasn't able to find a good description of the differences.
https://www-robotics.jpl.nasa.gov/publicati...itz/f1695_2.pdf

Most of the differences may be in the scoop.

Yup - this actual arm was destined to deploy Marie Curie on the surface at Meridiani Planum before the '01 lander was cancelled.

They have pulled the scoop away from the mole, exposing the pit and the depression left by the scoop. They have imaged this from several positions maybe to get a 3D model of the pit? Could we see some back-filling of the pit / depression before further hammering attempts are made, or maybe they will try and move the mole to a more upright pose by pushing from the other side during hammering?
Click to view attachment

Here is one set of the sol417 stereo pairs, from the left in crosseye/anaglyph/parallel renderings:
Click to view attachment Click to view attachment Click to view attachment
"the alien instrument descended as dusts of ages fell away revealing a sort of portal, as if a long buried Cenote emerging from the deep to accept the sacrifice"

Oh WOW. That is a HUGE amount of missing volume! Can that ALL be from compaction?

I'm starting to think there is a void UNDER the duricrust, and the mole punched a small hole through which is allowing the soil to drop down into a void?

It was partly wondering about this that prompted me to ask the question about densities a few posts back. Apart from the visible void there is the volume now occupied by the probe itself. If the regolith here is indeed very porous and lightly packed that would initially have helped the mole to sink. Maybe the hammering causes the stuff to collapse and there is now a much denser sand 'puddle' at the bottom of the hole.

The presence of duricrust implies the previous presence of saline water from which the water departed. To some extent, this compaction must be showing us how much water there once was.

IIRC, there was a paper about a year ago that about areas that were likely re-worked by Northern-ocean Tsunami deposits, the Insight landing ellipse was inside the area that could be reworked. That would make the site roughly analogous to the US channeled scab lands or other areas subjected to recurrent catastrophic glacial lake flooding.

The scenario seems to be that the mole encountered a duricrust layer beneath the reasonably loose regolith. When the mole encountered the cemented layer there was insufficient friction against the barrel from the surface deposits to let it penetrate and the mole effectively bounced around compacting the (comparatively) loose material. The friction applied by the scoop permitted the mole to begin to penetrate the duricrust but the effect diminished with depth and the mole bounced back, possibly with loose material sifting down to progressively refill the hole. There is no way to tell how deep the duricrust layer is but it could be measured in metres, representing the surface a long time ago.

Took the Sol 420 IDC images and was able to extract a 3D model from them...

https://sketchfab.com/3d-models/insight-hp3...281e93d4d8b42d7

Correct me if I'm reading this wrong, but that seems to me to be the opposite (vertically speaking) of what the team blog said on December 23: "The most convincing (at least to me) explanation for the backing out of the mole assumes that the duricrust is underlain by cohesionless sand." And further, "…motion of the mole provides an estimate for the thickness of the duricrust of about 20cm." You speak of a duricrust layer under loose regolith, but they speak of loose (cohesionless) material below the duricrust. And you speak of unknown thickness perhaps meters and they speak of about 20 cm. Perhaps they are wrong (they express uncertainty) but it seems like you are knowingly or unknowingly contradicting them.

Again, my understanding from this is that there is a duricrust on the top, and that it has a definite end within cm from the surface. Viking found this to be just a couple of cm, but here the team supposes about 20cm. Then, there is a loose layer of unknown depth below that in this locality.

Do you think the team is wrong or are we interpreting the wording differently? (I'm sure there is some degree of surface dust above the duricrust, but I was interpreting that as negligible, approximately or less than 1cm.)

https://www.dlr.de/blogs/en/all-blog-posts/...on-logbook.aspx

Wow! incredible sketchfab djellison, thanks!

It seems we've managed to collapse the sub-duricrust layer into a jumble of sand with what looks like the cohesiveness of styrofoam pellets, seemingly held together by a very weakly cemented loose matrix of muddy salt residues left over from eons of dessication, never disturbed until now. I'd imagine walking very cautiously here with my boot plunging into the subsurface regularly like dry quicksands. To further the Earthly comparison, very similar to what happens regularly at the beach when a layer fine sands is washed to cover over a deep layer of very large sand grains that were deposited without any small grains to fill the gaps, and so when the tide goes out and it all dries up it doesnt collapse under its own weight but remains loosely cemented in place, so you walk along as your foot plunges through a crispy crust to squish away large volumes of the larger mobile sand grains below, sinking deeply and softly with every step.

So now doing some very unplanned-for trenching studies in order to reveal the true cross section of the soil layers and how they react might prove critical to making safe progress with whatever plans are in the pipe..?

Did the lander footpads do anything unusual? Sol 10 and 14 images of the footpads look fairly normal.

Curious- why SALINE water? I was under the impression that caliche can form from groundwater and precipitation.

Now, when I think of weathering of rocks on Earth, as applied to Mars, I think of thermal (thermal-onion-skin, or freeze-thaw-splitting), physical (grinding away by moving sand or ice), and finally chemical (water dissolving the minerals (usually cations) that cement the grains together.

It would seem that Insight landing site resembles the Sonoran/Sahara desert model of caliche formation where occasional rain dissolves minerals as it trickles down through the sand, and either forms a duricrust at the water horizon (e.g. bath tub ring)
or vaporizes and deposits the minerals at a higher horizon (e.g. shower scale).