InSight Surface Operations, 26 Nov 2018- 21 Dec 2022 |
InSight Surface Operations, 26 Nov 2018- 21 Dec 2022 |
Nov 26 2018, 08:20 PM
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#801
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
Congratulations to the InSight team on a successful landing! We'll discuss the remainder of the mission here.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Jan 27 2020, 10:10 PM
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#802
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Member Group: Members Posts: 866 Joined: 15-March 05 From: Santa Cruz, CA Member No.: 196 |
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. |
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Jan 28 2020, 03:16 AM
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#803
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Member Group: Members Posts: 691 Joined: 21-December 07 From: Clatskanie, Oregon Member No.: 3988 |
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. 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 |
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