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InSight Surface Operations, 26 Nov 2018-
atomoid
post Oct 29 2019, 06:55 PM
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sounds like they want to be sure it wont tip over, then remove the scoop to inspect the hole, then simply set up for another pinning operation.

I wonder if they also need to correct it to the vertical, as it has already tipped over quite a bit and i doubt there is any intrinsic physics involved in the design or process that should make it auto-correct to the vertical, else any diversion from vertical might create an erosional feedback loop to that side. It seems the scoop will need to be positioned on the opposite side in order to pin it vertically. The worst case scenario is like hammering a nail where the initial angle is critical, even without hitting other obstacles on the way down, left to its own devices in this type of regolith the path of least resistance might ultimately result in a wide circle back to surface given no other inputs, but presumably they can locate the mole position using data from SEIS. From the looks of the current angle, the mole would seem to be ultimately headed somewhere beneath SEIS, if that matters, but in the best case scenario the ultimate depth being reduced by the length of the tether at that angle. how much better science can be accomplished at full depth vs the 'acceptable' 3 meters?
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JRehling
post Oct 30 2019, 07:49 AM
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I think the quality of the heat probe data as a function of depth could only be answered, precisely, if we already knew some of the things that the probe is there to measure.

The experimental design is to probe the local thermal inertia at 50 cm intervals, so the number of data points with a 5-meter penetration would be ten. Noise must certainly be much greater near the surface due to diurnal variations, which are great on Mars, so the least noisy measurements would be the last (deepest) two.
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MahFL
post Oct 30 2019, 08:40 AM
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QUOTE (atomoid @ Oct 29 2019, 07:55 PM) *
how much better science can be accomplished at full depth vs the 'acceptable' 3 meters?


The design min is 3m and the only difference I can recall from the briefings was at 3m it would take quite a bit more time to achieve the results.
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Phil Stooke
post Oct 31 2019, 06:26 AM
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The arm has just been raised a short distance above the surface. Another rise and we should see the state of the hole again.

Phil


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PaulH51
post Nov 3 2019, 10:23 AM
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Scoop pulled away from the Mole on Sol 332 smile.gif
Waiting to see the next move smile.gif
If me, I'd go for filling the pit, but what do I know? smile.gif
Attached Image
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ddeerrff
post Nov 3 2019, 05:14 PM
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Looks like it may have dropped down a bit after removing the scoop.
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HSchirmer
post Nov 5 2019, 03:41 AM
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So, Mars has a duricrust, caliche, or hardpan layer that impedes probes.

Hmm, what could we do about that?

QUOTE
This linear cluster of dark disrupted ground is about 7.5 miles (12 kilometers) from the rover. The length of this cluster is about 0.6 miles (1 kilometer). There are six impact sites, one for each of the 55-pound (25-kilogram) tungsten Entry Ballast Masses.
https://mars.jpl.nasa.gov/resources/4351/ba...rface-close-up/


QUOTE
Another image set, courtesy of the Context Camera, or CTX, aboard NASA's Mars Reconnaissance Orbiter has pinpointed the final resting spots of the six, 55-pound (25-kilogram) entry ballast masses. The tungsten masses impacted the Martian surface at a high speed of about 7.5 miles (12 kilometers) from Curiosity's landing location.
https://www.nasa.gov/mission_pages/msl/news/msl20120808.html


Perhaps the next Mars mission should make those "entry ballast masses" do double duty as mini "rods from god"(RFG).
Make the ballast into long narrow flechettes.

Heck, how about adding some electronics to the tail end of the weights, has NASA asked the Air Force to share some of the high-g electronics from the "MOP" (Massive Ordinance Penetrator) development?

QUOTE
Meet the Massive Ordnance Penetrator: The Air Force's Newest Bunker Buster Bomb
...
The bomb will burrow more than 26 feet into the ground through reinforced concrete. As such it requires extremely ruggedized fuzing, guidance, and other on-board electronic components to survive and operate through the huge G-forces..
https://nationalinterest.org/blog/buzz/meet...ster-bomb-87606


Question - could we have skipped the entire "mole" part of the mission by using a "rod from god" impacting Mars?
If bombs dropped in dense Earth atmosphere penetrate to ~9 meters, a "rod from god" in Martian atmosphere should go deeper. Add a temperature sensor on the tail end,. Add few hundred meters of trailing TOW-wires to the RFG, and use that for radio communication back to the main probe.
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stevesliva
post Nov 5 2019, 03:59 AM
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^ Deep Space 2.
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JRehling
post Nov 5 2019, 05:22 PM
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An impactor would have to leave a hole behind it that collapses, which is automatic if the depth and width would exceed the angle of repose. I'm not sure, however, if that would alter the requirements of the experiment by reconstituting the vicinity of the probe with broken-up ground instead of the native regolith in its natural state. Also, I wouldn't take for granted that antenna lines left outside of the impactor would survive the impact.

It seems to me that an appropriately-designed impact penetrator could meet the requirements but it wouldn't be automatic.


With both Mars and the Moon (see: Apollo) the problem is that the subsurface mechanical properties are not well known. And, FWIW, the Moon and Mars are themselves potentially quite different from one another, so the specific lessons from Apollo don't aid designing for Mars.

If Insight's mole never achieves its goal, we have learned a lot about this site for any future attempts, although the next try might be a very long time in coming. Another Discovery mission, Contour, utterly failed, and there hasn't been any re-fly since.
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hendric
post Nov 5 2019, 05:40 PM
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This was from 2015, but I don't recall anything in the Mars 2020 rover. It seems like it would be near perfect for a University program to specialize in penetrators like this - the small form factor means the cost can be relatively contained, testing would be cheap, and once there is a standard "mass balance penetrator" design, it can start being incorporated into missions.

https://www.nasa.gov/content/nasa-announces...mass-challenge/


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mcaplinger
post Nov 5 2019, 06:52 PM
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Penetrators were all the rage in the mid-70s to mid-90s (and flew on the Mars-96 mission), but the devil is in the details and it's not as easy to get anything useful out of them as might be supposed at first glance. https://ntrs.nasa.gov/archive/nasa/casi.ntr...19750004806.pdf

Maybe there's another thread where this could be discussed. InSight doesn't have a penetrator so it's off-topic here.


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climber
post Nov 6 2019, 02:35 PM
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How does all those "unscheduled" actions affect the seismometer data collection ?


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rlorenz
post Nov 6 2019, 06:47 PM
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QUOTE (mcaplinger @ Nov 5 2019, 01:52 PM) *
Penetrators were all the rage in the mid-70s to mid-90s (and flew on the Mars-96 mission), but the devil is in the details and it's not as easy to get anything useful out of them as might be supposed at first glance. https://ntrs.nasa.gov/archive/nasa/casi.ntr...19750004806.pdf

Maybe there's another thread where this could be discussed. InSight doesn't have a penetrator so it's off-topic here.


Some years ago I wrote a historical survey of penetrator missions and proposals. I think they really only make sense at Mars, but even then, you need a programmatic commitment to launch 'many': as there is an irreduceable terrain risk, so a 'mission success = 8 out of 10 vehicles return data' paradigm needs to be adopted.

https://www.lpl.arizona.edu/~rlorenz/penetrators_asr.pdf
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Phil Stooke
post Nov 6 2019, 10:44 PM
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"How does all those "unscheduled" actions affect the seismometer data collection ? "

Not much at all. We know when the arm is moving or mole hammering is taking place, and those things only happen during very limited times. It would be easy to take them into account.

Right now it looks like the scoop is being repositioned for another pinning and hammering session.

Phil


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PaulH51
post Nov 6 2019, 11:31 PM
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The mission have updated their FAQ about InSight's Mole Link

They also added a new animation "InSight's Arm Camera Stares Into the Pit" link

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