To the Cape!, Quackmire and arm troubles Options

[Guest_Sunspot_*]

Good Grief...

The middle wheel must be completely covered I should think.

[ugordan]

What the heck?!?!

[Tesheiner]

Aside of the "floating" wheel, the rover is clearly tilted to the right!
Just compare the latest rhazcam picture with a similar one from sol 1496.

[Floyd]

But the good news, looking at those two images, is that we have moved several cm up hill as indicated by the relative position of the triangular rock!

Floyd

[Tesheiner]

Here're some mobility data associated to today's drive. It was executed in six consecutive steps and each of them was expected to move the rover back some 55cm for a total of 3.3meters. Opportunity moved only 22cm with an average slip factor of 93%.

Fingers crossed!

[djellison]

Actually - it's not as bad as I thought.

My understanding is that the rocker ( the front wheel, thru the diff, to the bogie pivot ) can rotate + / - 20 degrees. The bogie ( the rear two wheels ) can rotate + / -30 degrees. And yes - if they both go max in the same direction, the rear wheel will contact the bottom of a solar array.

BUT - on the upside - I don't think pulling a wheely like we are is as bad as all that after all. Probably about half-buried wheel.

Attached - a low fidelity sim of the RHAZ having a look, the side view of the max bogie tilt, and a movie that shows, I think, the full suspension extent.

Doug

Attached thumbnail(s)

 

Attached File(s)

 mer_susp_ext.mov ( 268.92K ) Number of downloads: 358

 

[ilbasso]

Excellent illustration and movie, Doug!

Just goes to show what happens when you let things go around on 6 legs, instead of the 3 legs that the God of the Martians intended! H.G. Wells was right, again!

[nprev]

Well done, Doug, and thank you!

Man, that slip rate from the latest traverse, though...93%? Horrific. I suppose the blueberries are contributing significantly to this. Gee, why didn't the MER designers foresee them?

All humor aside, though, I think that it might well be time to ask some serious questions, as I'm sure the MER team is busily doing. If Oppy goes down there, she really might not be able to get out. The cliff is an extremely tempting and of course scientifically significant target; is this the time to roll the dice?

Hate to say it in a way, but I think the answer is yes. It would be much better to be stranded down there (God forbid) then out on the Meridiani plains with nothing, really, nearby to study. We would've killed to put one of the Vikings right where Oppy's trying to go, after all.

[Stu]

Having heard Steve S talking on this week's Planetary Radio show, I think it's v v unlikely there'll be any rolling of any dice. He was adamant that VC will NOT be Oppy's final resting place, that she has a lot more work to do outside, back up on the plains. For those who didn't hear the show yet - I say "yet" because everyone should go over to Emily's blog and download the show asap - SS said that they are looking at two possible "campaigns" for Oppy, post-VC. #1: "The Cobble Campaign", where Oppy would re-trace some of her tracks and go back and examine some of the interesting cobbles, stones and meteorites she scooted past in her haste to reach VC. SS said that the "Cobbles" are a very diverse mix, in great contrast to the bedrock seen by Oppy. Some are meteorites, some are ejecta from craters a long way away, and so represent samples of material deeper beneath the surface of Meridiani than seen elsewhere and so far by Oppy. He would like Oppy to go back and take a good close look at these to learn more about the sub-surface of Mars. Campaign #2 would be to go and find some more outcrops of rock and features where water came to the surface.

So, I think that if it comes down to a choice between a glorious game of Rover Roulette and a tactical if grudging withdrawl from VC, I think they'll go with the latter.

[fredk]

I agree there's work to do out on the plains. Does anyone have a clear idea of exactly what we might learn from an approach to Verde cliff? I mean, we have studied the layers pretty well on our traverse into Victoria so far. But judging from the imagery, the layers they talked about tasting on the cliff are quite a bit lower down than we've sampled so far? Is that all that matters here - getting lower into the layering? Or might they learn something worthwhile by looking closely at the same layers we've already tasted, but now crossing the cliff face?

[stewjack]

Having heard Steve S talking on this week's Planetary Radio show,

Download
A Mars Rover Update From Steve Squyres ( April 14 2008 ) ( 13.2 MB )
http://s3.amazonaws.com/planetary/radio/pr20080414_64kb.mp3

Stream or Download
Planetary Radio
WEB Page
A Mars Rover Update From Steve Squyres

Airdate: Monday, April 14, 2008
Running Time: 00:28:52
Listen: Windows Media | MP3

Jack

[Aussie]

[quote name='nprev' date='Apr 15 2008, 10:45 PM' post='112364']
The cliff is an extremely tempting and of course scientifically significant target; is this the time to roll the dice?

It would not even be a roll of the dice! Yes they bogged the rover. It happens when you drive over excavated holes, on Mars as on Earth. What I don't understand is that the direction of the drive was down towards the bottom of the scree, not towards the cliffs where there seems to be secure bedrock leading to what seems to be a feasible slope to the cliff face. I still punt on finger problems with distance and slippage when trying to go back and MI the scuffs as I cannot believe that they deliberately crossed the excavations.
It would be helpful if they would do updates when these incidents occur but I guess they have their hands full extracting the rover.

I really can't see the value in examining cobbles of unknown provenance when all those deep layers beckon.

[centsworth_II]

..."The Cobble Campaign", where Oppy would re-trace some of her tracks and go back and examine some of the interesting cobbles, stones and meteorites she scooted past in her haste to reach VC....

I remember being surprised and a little disappointed when Opportunity didn't take a closer look at this large pile before heading into Erebus.

[Tesheiner]

Well, after the attempt to exit the "quackmire" on sol 1502 there was no other one during this week and I fear there won't be any during the weekend too.
As already noted by Horton on the other forum, Opportunity was unable to unstow the arm after that "drive" and a second attempt on sol 1504 failed too. A third attemp is scheduled for today (sol 1505).

[Bill Harris]

"The Cobble Campaign", where Oppy would re-trace some of her tracks and go back and examine some of the interesting cobbles, stones and meteorites she scooted past in her haste to reach VC. SS said that the "Cobbles" are a very diverse mix...

This is not the appropriate time to backtrack and do that. The cobbles and other sporadics should have been examined visually and chemically a couple of years ago during the traverse _to_ Victoria when Oppy was within meters of the rocks.

--Bill