The Conjunction Plan Options

[dvandorn]

Well, yes, but... it's my understanding that this "shaking" plan actually improved the dust situation on Spirit's mini-TES. So while in Oppy's case the main dust problem may be in the internal optics, it was certainly worth a shot.

-the other Doug

[RoverDriver]

Well, yes, but... it's my understanding that this "shaking" plan actually improved the dust situation on Spirit's mini-TES. So while in Oppy's case the main dust problem may be in the internal optics, it was certainly worth a shot.

-the other Doug

AFAIK the MTES shake was run on the testbed and on MERB but never on MERA. Do you remember what Sol it should have run on MERA or do you have a reference regarding your statement? I'm not arguing with you, I ask only to refine my search and see if and when it was run so I can look up the activity.

On MERB we ran the MTES shake on sol 1680 (for 3 seconds) and 1705 (for 6 seconds) and I thought we were going to do a MTES shake before Conjunction but I see that we didn't. And so far I have not heard that either one resulted in significant improvement on the MTES functionality.

Paolo

[RoverDriver]

I really don't want to dash hopes of recovering the m-TES. But let's look at the facts; it is much easier for fine dust to drift into the pancam mast shaft and collect onto horizontal surfaces at the bottom i.e optics. The exposed (vibrated) mirror would be less likely to collect dust due to its slanting orientation as such */*. Again, apologies to all disturbed ones.

I don't have any way to prove my statement, but if you blow into an open tube the air is free to go through but if the tube is closed at one end, the effects of blowing will be felt only close to the open end. It is likely thet the depth of the effect will depend on the dynamic pressure but I believe that the additional deposition at the bottom of the mast would be minimal compared with the possible cleaning on the mirror. Moreover, the MTES is already completely blinded by dust so I doubt this will make things worse.

This is my uneducated view. I participated on the MTES shake activity but definitely am not a MTES expert.

Paolo

[dvandorn]

AFAIK the MTES shake was run on the testbed and on MERB but never on MERA. Do you remember what Sol it should have run on MERA or do you have a reference regarding your statement? I'm not arguing with you, I ask only to refine my search and see if and when it was run so I can look up the activity.

As with many things, I recall reading something but not exactly where and when. My memory is that when the regional dust storm hit at Gusev, there was some update somewhere (surely either posted here or linked to from here) stating that MERA (i.e., Spirit) had just completed a mini-TES shaking and that initial results looked promising. The news was in juxtaposition to the new dust storm, irony in the possibility that just after getting her mini-TES dusted off, a bunch more dust got dumped on the poor girl.

As with anything, I admit the possibility of remembering this incorrectly.

-the other Doug

[centsworth_II]

The October 31, 2008 Planetary Society update indicated that the shake would be tried on Opportunity first:

If Opportunity is able to get the “Mini-TES shake” to work, the MER team will have Spirit try it, Ruff said. “Spirit’s Mini-TES is not completely blind, but it is legally impaired,” he said. “If we have success on Opportunity, we'll try it on Spirit.”

If vibrating the Mini-TES mirrors doesn’t work, the MER team has another trick....Open the Mini-TES mirror to the outside and hope.... Mars sends a gust of wind to blow away the dust.

[RoverDriver]

The October 31, 2008 Planetary Society update indicated that the shake would be tried on Opportunity first:

If Opportunity is able to get the “Mini-TES shake” to work, the MER team will have Spirit try it, Ruff said. “Spirit’s Mini-TES is not completely blind, but it is legally impaired,” he said. “If we have success on Opportunity, we'll try it on Spirit.”

If vibrating the Mini-TES mirrors doesn’t work, the MER team has another trick....Open the Mini-TES mirror to the outside and hope.... Mars sends a gust of wind to blow away the dust.

Ah, this seems more plausible. I would be surprised if the MTES shake will be tried on MERA before it will give some significant signs on MERB. We'll see in a couple of weeks!

Paolo

[jamescanvin]

Well I see the images have been very ratty over the last few days/sols so it looks like conjunction really has started now (unlike when I posted my Bonestell update )

So here is the first bit of the Santorini Panorama that made it down largely intact.



James

[djellison]

Very much like ye-olde Erebus pan from back in the day

[CosmicRocker]

Nice logo.

[Pando]

Assuming that these plates were once flush with the terrain, I think it's interesting to speculate what mechanism would lift them out of place like that...

Martian manhole covers...:

Attached thumbnail(s)

 

[Vultur]

I think it's interesting to speculate what mechanism would lift them out of place like that...

Could it be wind? If one of the flat plates cracked upward (just from vibrations or some other stress) to the point where wind could get under it, maybe that lifted it. Does anyone have any numbers for wind pressure on Mars -- would it be enough to do that?

[dvandorn]

Perhaps something exposed the rock below the former sand line and the wind got in and eroded the rock out from below? Remember, the rock probably eroded down flat to ground level a few hundred million years ago, and then something (perhaps ground shock from the Victoria impact) pushed it up a little bit, and over several hundred million years, the less armored underside of the rock has been eroding away?

We're talking long time frames here, you know?

-the other Doug

[CosmicRocker]

Assuming that these plates were once flush with the terrain, I think it's interesting to speculate what mechanism would lift them out of place like that...

I would guess the assumption that they were once flush with the current surface is unlikely. They appear to be taller parts of the pre-existing bedrock that have been somewhat undercut by erosion, and which are still attached to the blocks beneath them.

It is interesting to consider the possibilities of loose plates vibrating in a catastrophic wind, allowing nearby sand grains to lift the pieces above the existing plain, but I think this is simply undercutting of local layering by saltating grains. We've seen more spectacular examples of this form of erosion in many places on the Meridiani plains.

[Doc]

I agree with your statement CosmicRocker. But what really interests me is the distribution of spherules with distance. I really don't know how far away Oppy was at the time when we started seeing spherules excavated by Victoria. But even at the current distance (1.25km), spherules are abundant *on outcrop.* Are we really still on Erebus rocks?

[SpaceListener]

Ah, this seems more plausible.

It would be done after the conjunction. Not now, too late. It is nothing sure but, the important thing is the persistence, it will work. That is when at the end of work of day, before stopping, Oppy must be facing to the prevalence wind (NW -> SE). Hope, someday, a gust wind will hit it. The persistence will work!