The red line, I seems to be dangerous since the sand might looks loose. The green ones is the most recommended.
Click to view attachment

Rodolfo

That's the manouver to avoid Purg-III?
Frankly, this terrain looks to me even more dangerous then the previous "valley".

And looking to the rear-hazcam pics, I'm not sure if this drive ended nominally or by slip checking...



Yes, BUT in order to take the green path the rover must do a turn-in-place manouver.
Mmm, soft sand + turn = Purgatory-IV?

I don't even agree that the green path is the way to go. It looks like a dead-end to me.

Should be interesting...

You are right Mike.
IF the only options were these two paths I would say the green one BUT making the turn manouver on solid rock. But there are plenty of options and, imho, the best one is: drive backwards exactly on the same tracks they came and then NW again (see here).

My proposal about The Journey to Victoria:
Not well considered, and still some question mark there...

http://static.flickr.com/44/163716877_e71b75a1f6_o.jpg

It's a possibility Mizar.
I agree with that NW then SW detour, but have my concerns with the E-W leg halfway to Corner Crater (yes, I still prefer CC ); it would mean a *lot* of ripple crossings.

We can take this leg of the journey a few Sols at a time. We have a _general_ idea of how to go, but we'll need to do hazcams to see exactly where.

It won't be a quick as it has been, but it'll be safe. I'll guess that the ejecta blanket will be a great driving surface with cobbles and no mooshy sand.

--Bill

Not if we are going to get there by sol 902!

We're late, people! Let's get going!

I hope (and think) the ejecta blanket at Victoria will be similar to what we saw at Endurance.

http://qt.exploratorium.edu/mars/opportuni...78P1301R0M1.JPG

Er... ...basically, not there, bar some pavement?

Bob Shaw

Yeah... Let's get going!

Oooo, dot.dk...It's a dream.

BTW, Tesheiner words gave this :

http://static.flickr.com/55/163831088_ef79b3cf8f_o.jpg

Yes, about the turning wheel is a problem. I didn't know how much Oppy has to turn. I think it is better to pull back again and look for a better way to go southward.

About your recommended route is fine but its last trace point, I cannot see its future route toward south. Need more areial map to study the best rail to the south among the crests.


About the surface conditions around the blank eject, I am still thinking about how it would be: firm, loose, smooth or rough with some stones. It is still to early to start to think. It would come into the debate soon after visiting the Crater Corner.

So everyday is uncertain until the next day!

Rodolfo

I'm thinking that the surface around Victoria will be different than it was around Endurance. Victoria was a much more energetic disruption and pulverized more of the "basal unit" under the Burns Fm. Endurance was barely a little _whump_ that tossed out evaporite slabs to be eroded and covered with the blueberry-sand present on the plain.

We'll see soon enough.

--Bill

As usual, the rover planners prepared the activity plan not only for the next day but to the whole weekend.
Sol 846 is planned for driving and the post-drive navcams are centered at 180º i.e. due South. We should expects fresh pics on Sunday evening (GMT).

This is an annotated navcam mosaic from sol 843 in which I plotted the current rover's position and where it would go assuming *no* turning manouvers.

Click to view attachment

Sol 844 navcams gave me the false impression it was climbing this big dune, but it's actually traversing on the dune's side.



Mmm, I gave you a wrong indication: "I agree with that NW then SW detour, but have my concerns with the E-W leg halfway to Corner Crater (yes, I still prefer CC ); it would mean a *lot* of ripple crossings."
It's actually the W-E leg which gives me some concerns.

-----

An updated rover's status report (here: http://marsrovers.jpl.nasa.gov/mission/status.html) including this note:



Well, the net move was about 5-6m not 20m. Conclusion (mine): drive finished by excessive slip.

Looks like a pair of dust-filled wheel tracks there already, leading from the pavement to the right of Tesh's 844 position to wards the 846 position ?

Kenny

This is path that I figured Oppy would take. Back around that non-indurated area and then back in the N-S trough groove.

Looking at Jammerbugt, it looks like the wheels churned up a lot of light-colored material just below the surface. Are we seeing a weathered zone of the surface of the evaporite that has been covered by drifitng sand? I wish we had a color sequence of this spot.

--Bill

The view in the drive direction on Sol 843.

Taken with the L2 pancam.

jvandriel

But, I don' wanna go this way! It's too soft and scary! We're gonna get stuck again!
I'm gonna sit right here and wait. You guys will be back in a few weeks after you give up.

We've had comments somewhere about the crazy "serrated" upper edge of some of the dunes/ripples around here. Well, this navcam shot shows beautifully that those serrations are just the ends of a series of mini east-west "cross-ripples" peeking over the ridge of the main north-south dune.

I don't know a lot about dune formation, but I'm guessing that the N-S dunes are the older, more long-term dunes (stable for decades if not centuries) , and the E-W ripples are the produce of more recent wind action blowing mobile surface sand and dust around? That could explain why they are softer and more hazardous to the rover (if that is in fact the case).

We did discuss this back at posts #205 and #206 on "Opportunity in a sand trap again" page 14. Tesheiner later said in post #234 page 16 that they were going to take color pics of this, so we may yet see them

Kenny

A view of Jammerbugt dune from Sol844:

Unless we're stucked again, by early next week, Oppy will hit the 8000 meters as well as the 5 miles mark. Even if we know that JPL count every move, I guess you'll all agree that this is quite something. To round it up, we can even consider that we are close to a 10 m/sol mean (hope we'll have it by the time we get to VC). When I first learnt the intended speed as well as the 600m minimum goal, I thought we were going to have some (little) mobility. After so many sol, I feel that 10m/sol is a LOT.

Another rough proposal of this incredible and dramatic journey to the promising VC.

http://static.flickr.com/77/164432241_8dcc549d5d_o.jpg

Yeah, Miz (mind if I call you Miz?), I am strongly in favor of the red section, at least. I'm slightly worried that the MER driver has decided to "boldly go where no man has gone before", and just try to tough it out in the sloppy sand. That could terminate the mission. (insert emoticon for hysterical weeping)
Let's hope prudence prevails.

Footnote added in proof: This is not a gut feeling; it is an eye feeling.

I wouldn't worry TOO much Shaka. They have been cautious so far..

eye feeling? You need help.

Nico

Good observations, climber.
I think this updated odometry can aid.
Click to view attachment
In the last 100 Sols, average speed was 14.2m/day, with many Sols around 40m and a couple of hits to 60m:

Well, Opportunity is definitely not stuck and moved ahead (actually zig-zagged) towards another safe outcrop on sol 846.

Click to view attachment

Below is a previous navcam mosaic (from sol 843) annotated with 844 and 846 positions.
Click to view attachment

http://nasa.exploratorium.edu/mars/opportu...78P1305R0M1.JPG

Hard to tell from this shot, but it looks like they made a bit of a mess up on the dune. Perhaps this was from the bit of churning we saw around the steeringly-challenged wheel the day before. Obviously, it did not lead to an embedding through drag resistance, as I pondered it might.

However, as your graphic shows, they also changed direction at that point, executing the dreaded "dune side turn in place" that we also speculated might lead to a "lamentation". Again, impossible to say definitively what that area looks like from the rear hazcam shot. Hopefully a backward navcam shot will give a better view (if they take one).

Brian

Note: I edited and moved this out of the "stuck" thread, which clearly they are not.

Sol 846 perspective view:

As of sol 843, Opportunity's odometer was at 7,985.5 meters. It's current position (info from the pancam data tracking web) is 12.8m in a straight line from that point making for at least 7998.3 meters on sol 846.

Either sol 846 was THE day, or it'll be the next driving sol. Let's wait for an updated status report.
It's really a big milestone.

A good hint. You must look for closer range, you will be less worried. So now Oppy will probably advance a much slower due to a more slippage check and a carefull zig-zag driving to dodge any look-alike loose sand and also the slopes. Now Oppy is inside of a new track toward the south. Then if you see in front that is tought, then pull back and take another way.

On the other hand, Squyres says :

“I honestly don’t know how difficult the driving is going to be between here and Victoria,” said Steve Squyres, lead scientist for the Mars Exploration Rover project. “The terrain we’re in right now has little exposed bedrock, and that makes it more treacherous than when there’s bedrock around. So we’re going to tread cautiously. But what lies farther ahead is difficult to say... we’ll find out as we go,” he told SPACE.com.

Oppy will lower its average advancement from around 17meters/sol to 10 meters/sol.

Rodolfo

It's looks a lot like the terrain near/around the northen edge of the Erebus highway - hard work, but traverseable.

Doug

Checking before driving over it.

The L0 navcam view taken on Sol 844 and 845.

jvandriel

Here is the Pancam L2 view in the drive direction.

Taken on Sol 844.

jvandriel

W00t, the beacon shines as brightly as ever!

At ~10m/Sol that means about 50-60 sols to Corner Crater, so that means we'll reach it around Sol 900. Then, almost certain inspection of rock layers for another 10 Sols (that I'm looking forward too), give or take a festoon MI mosaic, means the final approach to Victoria likely won't start until Sol 910...

If 10m/Sol rate is still possible on Victoria's slopes, that means another ~50 more Sols to reach the rim.

And don't forget that we have a software update in the pipeline - I think we'll find that she's going to b parked on a nice northerly tilted halting site at CC for at least a week as she goes through a full set of tests following the update.

That picture showed that Oppy was trying to transverse on an inclinded slope which is not a good drive tactic. It would have to trasverse at the bottom. The inclinded slope looks pretty good as a loose sand.

Rodolfo

FYI, sol 848 (today) is planned as driving day.



Images should be available around 16:30 (GMT).

New route trace. There are two possibilities. The ones firm is up to the outcrop. From there, there are two possiblities and the selection of the intended route (blue or red brown) might be better taken from the outcrop.

Click to view attachment

Rodolfo

P.D.(Red color is wrong. I am Datonic!)

The view in the drive direction on Sol 846.

Taken with the L2 pancam.

jvandriel

...and that's assuming there are no more mechanical problems or Purgatroid Events. The reason I picked Sol 987 (apart from the shape was partly the probability of some mechanical problems requiring a long stop and/or slowing of progress, and partly the ring of debris around the crater rim. As we can clearly see the large dunes Oppy's navigating at the moment on Tesheiner's map, that could mean that the remaining ejecta has weathered down to a nice firm, flat, playa*... or it might be the loosely packed, fine powdery death trap material...

So, I reckon Oppy will be doing very well indeed to be at the rim by Sol 960. But as someone once said, "I've been wrong before, and I'll be there again..."

*I should know better than to recklessly use technical words without checking I have the right meaning... I mean a hard flat surface, as seen before we reached the etched terrain.

Can't see any "red" path on the image.
Anyway, I would take the trough to the left.

---

Click to view attachment Ah! I'm happy today. Click to view attachment

Not brown either.... I would say a muddy green, Rodolfo.

However for the route ahead, there is a possibility that the view from the outcrop will show an opening to more bedrock to the right (west) - based on what I see on the orbiter image. Although this is obviously less direct than your paths it might prove a more secure method of making progress.

and congratulations to your team, Tesh - I thought Croatia gave them a tough game.

Click to view attachment Click to view attachment Click to view attachment

And now we know it was Ronaldo that ate all the pies...

This would make an interesting special effects image.

All you need to do is add some shadows, tracks. better size, lighting and perspective match for the rover...

New pics at the exploratorium after sol 849 driving. The rover moved about 25m (parallax) and is now back on solid rocky terrain.

http://nasa.exploratorium.edu/mars/opportu...cam/2006-06-14/

Sol 849 60 degree views:

Here is the view on Sol 848.

Taken with the Left navcam.

jvandriel