In the general terms, the route is fine. By that route, it seems most likely that the ripples are lower that makes easier and less riskier to cross. I am not sure that the dark ripples will lead a flatter ripples since I think the colors are subjected by the erosion of remant of stones different than that zone (impact stones).

The typical valleys of that zone is oriented more less 10degree from north since the wind blows from north west to south east. That means that the south east side of ripple is softer (fluffy) than the ones of north west side (paved by the wind erosion).

To overcome, by climbing it, it is most desirable to go in diagonal and not in straight line of ripple slope if it is somewhat tall for the MER's capabilities (slow speed).

At all, the alternate route might be is to go as far west until catch the valley that will lead to south up to Mogollon's rim. This is like a semi-tunnel way.

Rodolfo

Sol 625... another long drive

http://marsrovers.jpl.nasa.gov/gallery/all...UP1315R0M1.HTML

... and moving SW again!

Based on the radials to the west crater and some features at Erebus I plotted the following positions for sols 624 and 625.

Click to view attachment

I think Oppy is headed to that outcrop at the NW of Erebus.

I think your positions are reasonably close. It's hard to say since there are not landmarks nearby. Attached is a Sol 625 Navcam image, looking southwestward, cropped and stretched 5x. It shows the target NW outcrop and Mogollon beyond it, with the dunes to the left (East). Oppy will be heading between the ripples along the right side of this image. Once she gets to the NW outcrop the driving will be easier for a while and hopefully she'll get there before the dust storm.

--Bill

I think you're about right on 624. I couldn't begin to guess yet on 625, but if we actually moved that far that's fantastic.

I don't know if anyone has mentioned this, but there's a cPROTO image of Erebus available at a resolution of 0.5 meters per pixel. They actually spotted Opportunity on sol 601-605 with the image.

http://www.msss.com/mars_images/moc/2005/10/24/index.html

And take a look to a similar shot taken on sol 624; if I'm not wrong it's the first of five navcams. We can really see Oppy's advance towards that outcrop.

I've been noticing them; the Oppy-drivers are doing a commendable job. This has some of the trickiest soil conditions that we can have and they've been making good time.

--Bill

The long and winding road, quite a little hump they've driven up

Oh yes, Aldo:

http://www.unmannedspaceflight.com/index.php?showtopic=1580

Here is what I get for Oppy position after Sol 626 drive.
I'm not 100% convinced of that one, so if anybody wants to do some distance estimations to confirm that position (or not), it will be appreciated.

Another map, updated with sol 627 position.
I would like to have more reference points to refine the estimated position, but navcam images are only covering a small part of the rim outcrops.

This will be my last map until all navcams for sols 621, 624-627 are downlinked. After that, and unless the MER team provides their updated map, I will try to improve this last version.

PD: Dilo, I'm looking forward your vertical projections...

New traverse maps available at the MER webside, as already noted by general on the Erebus thread.

http://marsrovers.jpl.nasa.gov/mission/tm-...nity/index.html

Here is that same map overlayed on top of the one I have been using here during last drives by the sand.

Click to view attachment

You can see some discrepancy on the routes during the whole travel through the outcrops and then they almost finally fit together on sols 626 and 627.

The route by the outcrops on the background map was plotted based almost completely on Dilo's work with vertical projections. I don't know your opinion, but I'm 99.9999% confident on that. Does anybody want to double-check it?

As already said before, it seems that the official traverse map is displaced to the north.

Good match up, Tesheiner.

I've worked on my own version of a route map based on Oppy images with input from your and Dilo's route maps. My opinion? The route maps presented here are more accurate than the official JPL/OSU maps.

More later...

--Bill

Hi all.
Time to return here, this map refers only to last "Mogollon" days and should be integrated from the previous ones from Bill and Tesheiner.
I followed the suggestion to put projections inside MGS global image.

Welcome back, Dilo!

We were all missing your maps.

Exactly Dilo, you was missed!!
Thanks again for the PMessage

Thanks to you Tman!
Here below I extended to previous way-point (Sol626) based also on direction of distant features, in particular the small crater on the left (visible in the inset)... this was another suggestion from Forum members in this thread.

Edit: further improvement / added Sol630 projection

Thank you Dilo and welcome back.
Your map tells me that we're close, lets hope we dont get any limited sols so that we can have a look at that crop of rock now around the weekend please! Ive been waiting for that a long time.

Hats off for this work, Dilo!
My first impression, few weeks ago, was that it would be too difficult, if ever possible, to match ripples, ripples and more ripples together. Well, here is the answer.
BTW, are you planning to reconstruct the whole route back to sol 621?

Just a small correction.
The pics from sol 630 actually represent the driving made on sol 627. Oppy drove on 627, and the nav/pancams were planned for 628 but not executed. They were re-planned for sol 630 and finally shooted.
Wrt the placement for 627/630 I would expect it to be a bit northwards. Per your map, a->b is 66m while b->c is just 6m. MER mission updates report 51m on sol 627 (a->b) and 39m on sol 631 (b->c). I know we should take those numbers with a grain of salt, but imho the discrepancy is too big.

Thanks for the correction on Sol numbers, Tesheiner!
About travelled distance, I'm pretty confident on Sol626 position, because I established it by triangulating 3 far elements. About Sol630 (627) position, there is some degree of uncertain... but, are we sure that this last panorama was taken at the end of the daily traverse?
I agree about the total distances traveled that do not match (90m vs 72m)... but attention, I didn't consider maneuvers nor slippage, while I suspect NASA reports refers to odometry data. In fact, I consider simply distance between initial and final waypoints, without considering the path; this can produce a sensible underestimation of the traveled distance!
Finally, about plan to reconstruct the whole route back to sol 621 (and eventually correct also orientation errors before it), I already produced all vertical projections to assemble. All depends on my ability to find distant referring points to precisely establish rover positions, so is a delicate and long work and cannot guarantee success.
Anyway, I definitely will try!

Hi Dilo,

Wrt sol 626, my last attempt was made using 9 control points, but I don't remember if it was posted here or not. I should check it (Edited: it's here). With that estimation I've got around 93m from 626 to 631 positions. Anyway, this is really not a big issue.

Wrt sol 627, there is only one 360º navcam pano taken on sol 630, plus two sets of "drive-direction" pancam mosaics. I also took 3 control points to estimate the position AND double-checked it with some parallax calculation to the first outcrop, now named "Olympia".
I did again some parallax calculations to the piece of outcrop which can be seen on the middle of this pancam image (http://marsrovers.jpl.nasa.gov/gallery/all..._P2412L2M1.HTML) taken on sol 630 (i.e. after 627 drive) and the result is:
---
Camera: PANCAM
nl: 510
nr: 601
dim: 1

object distance: 27.4 m, one-pixel error: 0.352 m
object dimension: 0.8 cm
---
That outcrop is a bit north of Olympia and can be recognized (I think) on your last map, just below the "b".

Btw, the access to the pics with drive id "##" seems to be solved at the MER webpage.

I'm looking forward your whole route back. Let me tell you I've generally used the following reference points:
- North/south features seen on an unnamed crater to the east.
- Dark outcrop at Mogollon rim
- Outcrop east of Olympia.
Now I'm trying to refine those estimations by including Viking & Voyager craters, but they are barely visible on navcams and sometimes may be confused with jpeg artifacts.

I have a little confusion about the exact route north and around that dunefield getting from the Four Lane to Olympia. Based on my observations at the time, with reference to Tesheiner's bearings-to-features, I think that it is the lower track on the attached map. But Dilo seems to indicate a differnt route, shown as the upper track on my map.

The reference points used by Tesheiner are the best there are in this area.

FWIW...

--Bill

Let me add something to the confusion, sorry.
I overlayed Bill's picture on my map; the result is a bit fuzzy but its enough to show the difference about all the proposed/calculated paths.

I hope we will be able to solve this puzzle.

Ah, I see that I missed the Sol 626 waypoint, and that is the major difference between your and my paths. We are playing "blind man's bluff" here since there are no landmarks to verify location. Let's face it, one ripple or trough looks much like the other. At best, we are guesstimating (guess + estimate) positions when going through that ripple field. Except for being right for the sake of correctness, it doesn't matter in that area we just passed through-- the paths show the general route Oppy took. Now that Oppy is at Olympia and moving towards Mogollon itis possible-- and there is the need-- for accurate positions that can be based on visible outcrops and distinctive ripples.

It's been fun, though. Better than any video game.

--Bill

I wonder whats happening here?............ dont they only take images of the wheels like that if theres a problem? I noticed they only moved a few metres forward, perhaps there was a problem wth the wheel during the drive?

Maybe it's time to see if the sticky wheel motor has been cured

The MER Tracking Data Interface for Sol 639 gives

639 p1149.03 0 0 0 0 0 0 frhaz_RAT_bit_check_subframe_loco_pri_56

for that sequence (p1149) of partial-frame FHazCam images. I'd guess that "RAT Bit Check" is checking teh RAT bit, so I dunno what the sequence of right wheel images was for. I'm new at reading the tracking data, so I dunno...

I'd agree with dot.dk that it _looks_ like a mobility test for the right steering motor.

--Bill

Or if you run the whole sequence, you can see the rat rotating just on the right of frame

Doug

I totally agree with you, Bill. Even if I do not achieve a perfect positioning for previous Sols, we know with good approximation the path through the "boring" ripples... You and Tesheiner made a very good work on this item and I hardly could reach/overcome your precision. Now that Oppy is again on interesting outcrops and is starting to explore the Erebus rim, is better to focalize on incoming Sols with best precision.

Anyway, I reconsidered Sol627 position (Sol630 panorama) and, after adding the missing panorama portion and the orientation respect to the "West crater" (highlighted by the red arrow) I obtained a larger travelled distance between Sol 630->631, in perfect agreement with your/Nasa estimation!
Click to view attachment
Tesheiner: Are you really still seeing Viking & Voyager craters?

Spirit seemed to clear itself of its sticky wheel. Anyone know what the duration and/or distance driven while Spirit had the problem? How does that compare the duration/distance of Oppy's stuck wheel?

>Or if you run the whole sequence, you can see the rat rotating just on the right of frame

Well, Duh, it _does_, doesn't it.


This route-tracing we've done around the North Erebus region has been enjoyable. There is is no reason-- or means-- to have close precision for the "up and around" route, one trough could have been used as well as another. Now that Oppy is on the evaporite outcrops, there is the need-- and the means-- to have precise locations. I was more worried about why my path didn't agree with the concensus; I see that I went from "a to c" without considering "b".

I'm amused. In another discussion group, they were complaining that all Oppy was doing was looking at b o r i n g rocks and sand, whereas we've been plotting her path from 35 million miles distance, plus several thousand to our individial homes.

--Bill

I enjoyed that too.
And about the route precision on the dunes “detour”, I think that at the end we’ll have to live with that uncertainty of, let’s say, 20m around each sol position, and that’s all.

Dilo, last time I saw V&V was on 624 navcams, here. I used those references to refine my first estimation for that sol position. They were barely visible and actually could be confused with jpeg artifacts but the headings to those little features were conclusive.
I dunno tf they are still visible today, but I would say yes.
And those little craters are best seen on pancam pics. When was the last time a 360º pancam mosaic was taken, sol 621 or later?

It's not the same thing. Spirit had a sticky drive motor which never failed, just started to consume more current. Oppy has a broken steering actuator and it is not sticky but really kaput. It doesn't respond to commands. However, miracles have happened before with the two machines. I think they had all their bad luck back here on Earth (just read the book!) and are now cashing in the good times.

Is that really true? It's not responding to commands now.

I thought that is was it was working but wouldn't drive beyond 7 degrees of straight and was therefore not being used in case it really did get stuck and at a less favorable angle.

Worth a test now and again to straighten it those last few degrees I suppose. But I wouldn't bet on any motion apart from that, it's not worth the risk.

James

Opportunity didn't changed location in the last 9 Sol, but now I added partial PanCam color panorama from Sol634, showing probable movement direction in immediate future (South). I deliberately removed the tall ripple on the west side because was hidding the features behind it.

I don't know about everyone else, but I've had my fill of this place. It reminds me of when you're on a driving vacation (holiday) and you get off the highway at some obscure town to have lunch. Your lunch is terrible, your car breaks down, you get lost looking to get back on the highway, and all you want to do is get moving again. When I write my Martian tour guide, Vostok, Viking, Voyager and Erebus will be in the "Places to Skip" chapter.

Can we go now?

Obviously not a geologist then...

Hehe! I know what you mean, because it really has been a long time in one spot. But this really is a scenic place. Look at the view, take in the local culture. Brush off a rock and sit down for a while, run some long Mössbauer integrations, APXSs, and don't forget to take some MIs. Not to mention the recently successfull Mini-TES test.

There was just a lot to do here, and I'm afraid it isn't over yet. This is quite an expansive outcrop with quite a few interesting things to look at. It looks like Opportunity will do a bit more with it's robotic arm through sol 643 according the the latest Opportunity update.

I hope to get moving soon, because I see some even more interesting places to stop again, just down the road. I'm eager to see what lies south of us, as we all are, but it looks as if there are just too many opportunities to ignore around Erebus. I don't kow about everyone else, but I still don't understand many of the things we've seen since arriving at Erebus.

Is it better to be in a situation like Spirit, with rocks everywhere, or Opportunity, with hardly a rock to be seen? Well, you see, in the one case, you have a ridiculous number of things to inspect, which on the one hand is good, and on the other makes it harder to find the really interesting things, but then with the other case, those rare things you do find might not be all that interesting, but if they are, they seem all the more interesting for the lack of anything most of the time otherwise, and while I personally would like it if Opportunity headed to the massive crater to the southeast, I doubt they'll return to this weathered crater any time soon, so why not poke around a little? In other words, gimme a G, gimme an O, gimme a J, gimme a P, gimme an L, what does that spell? GOOOOOO JPL! <jumps up and down energetically, causing the air to lift my skirt ever-so-alluringly>

EGD, sit down, fire up the Gameboy, plug in the iPod and relax. We're going to be here with the rock hammer and handlens for a few weeks. It must be a genetic thing, geologists do this.

Agreed, Tom. This a very rich area, there are so many pieces of the puzzle spreading out on the table. They are starting to piece together into a nice vista, but it's hard to tell whether they are toasters, windmills or contacts at this point. But I do think it safe to say that we've not seen a blender, yet...

--Bill

Actually, I have a massive interest and background in geology. My posts will bear that out. Endurance was nirvana for me. I never wanted to leave it. Sure we're going to see something interesting at the exposures we are maneuvering to get a look at. But I'm also a traveller and an explorer (or I was before I settled down to have a family). I want to get to Victoria which I believe will blow our minds when we get there.

I think ElkGroveDan is reflecting a concern that has been growing in my mind at least that we could get a mission-ending failure at any time, and it would be just too bad if we don't get to see Victoria.

The odds of seeing anything new right here at Erebus are darn low, especially on this Olympia plain. I doubt if there is anything here that would change our view of Martian geology.

So, get over to the cliff on the south just in case there is a dark layer to be investigated (I don't think there is), and then thread the dune maze to Victoria, where we just might find something Mars-shaking.

Scott

I'm with sranderson on this !
Although I do understand the geologists very well: this is, after all, a scientific
exploration and not a sightseeing trip: and of course, the geological studies are the most important thing of the mission

But the problem is, that we just don't know how much time we have left.
It's just as sranderson wrote: the probability of discovering something really new
is higher the more kilometers we move from the already well-studied location.
So it's a tradeoff between quantitatively more of the same or very similar
science at the same location (stopping at every possible outcrop etc.)
on the one hand and the prospect of really new discoveries when reaching different kind of terrain (i.e. priority on driving on and only study the *significantly* new things)

It's just the same as with Spirit's descision to climb on top of the Husband Hill
which, too was controversial between the geologists and the mounteneers but in the end we all agreed that climbing the top was the best descision that could be made !

So I'm quite sure that if/when we ever reach Victoria it will be the same and frankly I'm a bit afraid that by then, we will have reached about the end of Oppys life time, at a time when many interesting geological investigations sould only begin ... So I think every remaing day in the rover life time could potentially be better spent at Victoria than on intermediate targets ...

of course, there is no guaranty and maybe even Victoria turns out to be geologically not so intersting ... but that's the inherent risk of any exploratory and scientific endevour ... or, to summarize and put this with the word of Steve Squyres:



(Steve Squyres, October 4 Opportunity Mision update)

I'm confident that Oppy will still be in the Erebus area until late in January. There is plenty to look at here and best of all it's so accessible. We can poke around Erebus for a couple of months and we know we'll be taking readings of interesting rock almost every day if we want to.

Travelling to Victoria will be exciting I'm sure but let's take the bird in the hand first. "We don't know how much time we have left..." - now wouldn't dying halfway to Victoria be a waste of the chance to examine the pretty decent rocks around this humbler crater?

Also, for those who have forgotten, these big craters can be hard to get into (and out of). We may get nothing more from Victoria than a great panorama and other remote sensing (if we can get that close). Not a waste - but not the most valuable thing that Oppy can possibly do either.

yes, I agree: that's the "exploratory risk" I mentioned.
But the reasoning could also be like this: while I think the more prudent approach was totally justfied in the beginnig and main part of the mission .. we are now long into the extended phase and, after having already achievd several times the initially expected (scientific) "return on investment", couldn't we now afford taking a little bit more risk than in the beginning ?
And of course, by "taking risks" I do not mean "recklessly breaking new driving records or so" but just a shift in priorities from "stopping as much as possible and driving as much as necessary" to "drving as much as possible and stopping
only for the really new discoveries"

I'm confident that by christmas we are already on our way to Victoria, covering
about 40 meters per sol with 4 or 5 driving sols per week ...
at least that's how I interpret Steve's October 5 comment



And by the way, I like sranderson's comment that the biggest discovrey might just be waiting for us somewhere in the dune maze on the way to Victoria ...
... the journey is the reward ("der Weg ist das Ziel")

Someone mentioned in the Spirit route map discussion how the official Spirit route maps recently have adopted a similarity to Dilo's, by including an inset of a nearby vertical projection.

Interestingly, I've also noticed a recent change in the Opportunity maps, with those including a shaded area highlighting the larger drifts, similar to Bill's maps.