I can't believe we are only a 100 meters away -- absolutely thrilling.

Michael-T (right) and Climber had a 2 hours meeting this morning in Toulouse. It's nice to meet with another UMSF'er, specialy the first one .
Here is a proof of the meeting including our support for a drive to VC, ASAP

Click to view attachment

Oh brother!...
(Watch your derriéres, Doug's boots are watching... )

No beer...hm. Next riot in Belgium

Nico

I don't know if anyone has brought this topic up before, but looking at the scalloped rim of Victoria and reading somewhere that it might be due to collapse at various points along the rim, is anyone worried that the ground could give out under Opportunity if it got too close to the rim at the wrong place? Just wondering if this is a valid concern.

I think the same concern applied to Endurance. There we saw some blocks that moved somewhat when Opportunity ran them over.

My gut feel is that after 'several billion' years of consolidation by meteorite impacts etc, we have a reasonably stable surface. If the average slope of the walls is about 20-25 degrees, as we saw with Endurance, that indicates a slope of less than the theoretical metastable angle of repose (around 35 degrees), suggesting some kind of downslope transport mechanism.

We can just speculate on the nature of such a downslope transport mechanism. I mentioned meteorite impacts before, but my own pet theory is that the key to many of the features we have seen on Mars is related to the significant proportion of hydrated and hydratable minerals present in the Martian regolith. Cyclic volume changes due to adsorption-desorption of the evaporitic components could cause effects similar to those of solifluction creep, some evidence of which we have seen on the slopes of Husband Hill over at Gusev Crater.

The Victoria Crater is a very old and eroded crater. Around the rim must have a stable surface. However, it is generally that the top of the rim is the most difficult part to go down since the slope is higher. But it is rather of short distance. After that, the slope will become softer until reaching the surface. Around Victoria's rim there are many passable ramps to the bottom, the easier ones are in the southeast, the two others is between both Cabos (Cape and Frio) and the other is north of Cabo Cape.

I think that the initial Oppy's objective is to go to visit some parts of rim, probably to visit the beacon and also to the others sides in order to identify any interesting wall around Victoria Crater before going down the slope.

One more week on Victoria

Rodolfo

What a coincidence! I have a cat named Toulouse.

The houskeeper probably washed his favorite rugby sweater in hot water and tossed it in the dryer. That happened to me once and I was cranky for an entire week.

Replying to concerns about the crater rim being unstable... From my experiences scrambling around steep slopes on this planet, unstable edges can be encountered anywhere there are steep slopes, and the age of a slope is not a reliable predictor of the likelihood of encontering one. Fortunately, there are usually visible signs that should warn one to be cautious when approaching the most risky ones. You can be sure the team operating this robotic wonder are looking out for them when the rovers are near precipices.

Maybe part of the delay in finally reaching the rim is due to The Team waiting for more orbital images of VC... that way they could compare them with previous images for any signs of slippages around the rim, and identify any potentially crumblesome areas..?

Yes I agree it. The rim which has vertical fall, or alcoves ones, must be taken with more care. That is around Cabo frio o Cabo Cape.

However, the Mars lower gravity and the MER weighting about 80 Kg along with 6 wheels, has very low pressure on the surface that will hardly produce avalanches or gullies. The origins of gullies might be caused by the seepage of groundwater or brines, outbursts of CO2, snowmelt, geothermal activity, or dry flows of windblown dust and silt. They found gullies located at middle and high latitudes, particularly on interior walls and central peaks of craters, on pit walls in the south polar region, and on walls in two large valleys (Nirgal Vallis and Dao Vallis). Typical middle-latitude gullies occur within a few hundred to five hundred meters of the local surface. The case of Victoria Crater has no more than 70 meters deep.

Gullies have three characteristic parts: head alcoves, channels that extend downslope from the bottoms of alcoves, and triangular aprons of debris that broaden downslope. The head alcove is a depression that tapers downslope. It may be small or absent if it occurs at an overhanging rock layer.

I think that the Earth produces avalances at lower slopes than to Mars due to three times greater gravity, knowing that the surfaces of both planets have the same properties, doesn't it?

Rodolfo

Click here to see an interesting article about gullied slopes on Mars.

Click to view attachment


Looks like there's been a lot of "activity" at some point in time around our arrival area...

The problem is that this is a metastable system. Depending on whether or not these slopes are at or near the angle of repose, they are stable for the current conditions. The energy inputs are diurnal temperature changes or gentle but persistent winds and whatever else. This is a house of cards: additional input into the system by way of vibration form the rover's movement or weight would cause a re-adjustment. Look at the little dust slump we saw at Overgaard. The best terrestrial example might be a snow-covered slope in an avalanche region. One step and boom.

We'd best be cautious.

--Bill

Exactly. It may be reasonably static under current conditions - slow movement and accumulation of dust. Now suddenly there's going to be a heavy block of metal wandering all over the place, putting pressure on rocks which have only experienced the force of piles of dust and the occasional gust of very low-density air.

Maybe best to reach out with the arm fully extended and give the outcrop a couple of good whacks to see if it's safe.

Brian

'Crumblesome' somehow reminds me of cake, and then I catch myself wondering if the outcrops are layers of compressed shoes...



Those (the dark patches) certainly are intriguing features. To my naive eye they appear to lie on a less-steep section of the ramp. Could it be caused by sapping? Picture a fragment of one of the large tilted slabs underlying the ramp slipping a few inches down-slope, with a shallow depression visible on the surface..?

I really didn't intend to spawn undo concern. I only was suggesting that any slope can have parts that are ready to fail. I think risk to the rover will not be high. As already mentioned, the same kinds of risks applied to Endurance, and we didn't see any parts of the rim that appeared ready to collapse.

Not claiming for a moment that this is scientific in any way - it's played about with so horribly I can imagine some of our more accomplished Image Mages groaning and shaking their heads in disbelief - but I am getting quite excited by the "gully" in the bay up ahead... To my 'naive eye' it looks like material has flowed over and between underlying features, channelled down into the crater, but the flow doesn't appear to start at the very edge, rather some distance underneath it...

Click to view attachment

Whaddya think guys?

Looking forward to seeing this area in more detail soon

By the way, has anyone else noticed this..?

Click to view attachment

What are you suggesting? That there had been a small crater on the annulus at some point in the past, and Victoria's edge has since slumped, causing the two to intersect? It hardly seems likely that an impact -- either direct or secondary -- right on Victoria's edge would leave anything resembling a crater, instead of simply initiating a local collapse of the crater wall.

Not suggesting anything, just asking if anyone else had spotted it and thought "Hmmmm...."

Having said that, we know of at least one impact on the annulus because we're, um, currently parked right next to it...

More likely, I know, that the feature is simply an eroded slumping feature. I just wondered if anyone else had spotted it, thassall...

You know, we had a lot to share and a to send to the other UMSF'ers.
Sorry, no beer this time, and yes it was in Toulouse. You know, Michael came from Hanover to spend a week there without computer access so, as I leave one hour away from there, I brought him some fresh informations.
It's just increadible to actualy TALK to an UMSF'ers instead of write. I realise that what happen on Mars now is FOR REAL

Thank you both guys! That was very helpful!

EDITED: Work in progress (Thanks to Dilo too! ):

http://i16.photobucket.com/albums/b14/ustr...ictoriamap2.jpg

Just our luck that whatever process gets images from Opportunity out onto the web would break down as we approach the rim, looks like we're going to miss Oppy's arrival at Victoria Crater.

The JPL Exploratorium link is fine as Spirit images have come through the past two days. What are your refering to?

Pictures from Opportunity have got stuck somewhere.

Take into account that the usual evening (around 4pm) downlink window for Opportunity currently corresponds with the early morning hours here in Europe and is continuosly drifting towards later times. It means that the DSN station which would be responsible for receiving the data in this timeframe is Madrid which we know has it's 70m dish out for maintenance.

Ok, the data could be downlinked later by Goldstone but I have the feeling that this later timeframe is currently booked for other missions.

Patience. We'll get those pictures and will be moving again sooner or later.

Its not a data transmission issue, but whatever process moves images and other data out on to the JPL and other websites is broken at the moment.

Just a quick note on DSN tracking of Opportunity.
Just looking at our schedule, it seems that Canberra will be doing a lot of 'direct to Rover' comms with Oppy this week on both our 34-metre antennas as well as the big 70-metre dish.
See a brief version of our schedule here.
I understand that all is well. Just a little patience everyone.
Cheers
Astro0

PS: Hey, I just noticed that this is my 100th post!! Yippee!

I luv that Ustrax.
Anyway, what is confusing is that I've lost the North since the picture has been rotated. I understand that you shouldn't put North on your picture since it's an "artistic" one but can "others" put it back on the maps?
Thanks

Thanks climber.
I didn't put it YET...
I believe North is left...ain't it?...

Thanks for the DSN perspective - I guess flicking to new flight software would be something you might want to do with plenty of realtime DFE/DTE comms.

Doug

Congratulation for your 100th post Astro!
One comment and one question :
1- It's incredible to note after so many years that Voyager II get DSN time every day!
2- regarding Oppy, I understand that we canNOT loose informations from the Rover. I guess she will not delete files untill been told to, i.e. we're sure we've got files downloaded. Since Spirit hicup with the flash memory, does somebody know the procedure? Are the files deleted right away when we have them on the ground or is this done once in a while? I didn't see this question been addressed, at least I'm not aware of.
Thanks
Climber

I think this is about right... yes..?

Click to view attachment

If I'm right, then looking at VC pics, if in doubt of your bearings, "Sofi" is roughly due SSE...

Thanks to Astr0. Your posting has helped us much. I was looking for that without success.

About Climber note, I know that MER rovers has many picture still kept in their memory for a long time. These pictures are of low priority. You can check it thru the Pancam database reports.

About the cardinality of Victoria Crater shown by Stu is almost right. Among the Alcoves, Cabo Cape and Cabo Frio in which Oppy will arrive is oriented to East but a little north.

Rodolfo

Am I imagining things, or did I read somewhere that Voyager II contact was used for training?

Are there any tracking reports or information out there indicating when Oppy will finally start driving again towards Victoria?

Tosol is very early Sol 943, 6 or 7 hours from uplink - and there's no tracking information for that sol yet.

940 was IDD work for Mossbauer placement
941 was IDD work for APXS placement
942 was targetted remote sensing.

Things are happening a bit slowly - people should stop wondeirng "when's the drive, when's the drive" because then you're setting yourself up for dissapointment if there's a drive fault or it's only a short drive etc etc.

We'll get there when we get there. Not before.

Doug

Yes Doug I agree...As Mr. Squyres pointed out "The earliest we can possibly arrive there is late on Sol 943, and that's only if we get several lucky breaks. It could be later than that."
I'm preparing myself for an arrival for Thursday or Friday and then a whole weekend of in situ work...
Later...It could be later than that...

centsworth_II asked: "Am I imagining things, or did I read somewhere that Voyager II contact was used for training?"

No, that was Pioneer 11 before its eventual demise. The Voyagers are still transmitting vitally important science as they approach the outer limits of the sun's influence... They are contacted every day, I think, in part because they assume something is wrong and go into a form of safe mode, seeking the missing signal from Earth, if they don't have that contact. Maybe that old fault protection scheme couldn't be programmed out.

Phil

A little confused here

Steve wrote in his update they could get there at the earliest by 943 if they get several lucky breaks.
"Lucky breaks"?

Does that mean that the IDD campaign worked as planned or? Apparently the IDD work was succesfull according to the latest JPL update. They state that Oppy sucessfully did a grind into Cape Faraday. But here I'm a little confused too. Do they only know it was successfull from engineering data as we have not seen pictures of the grind? Have JPL seen the pictures? They are not at the tracking site either?

From Steves blog it sounds as if they would drive after finishing up the IDD work as soon as possible (sol 943). But in another interview he talks about booting into the new software before moving.

I'm not criticizing the team at all here. I just would like to know more than the 0,000001 % of the data

Also, remember that we don't have really good slope information from the MOC images. There are some interesting features right at the rim that could indicate albedo differences on ground that is still sloping up towards the rim drop-off, or could indicate that the drop-off has already begun at that point.

I imagine that the long drive "to the rim" will be designed to culminate at the last point where they are *certain* we are not descending into the crater's inner wall slope. Then Oppy will look ahead, see how much farther it has to go to reach the actual precipice, and make small drives to get to its first quick-and-dirty Navcam look-around point. Only then will they plan the drive to the first major Pancam panorama location.

So, while we may drive to within 5 or 10 meters of the rim by Friday, it might not be until next week sometime that we arrive in a position where we can see the crater floor.

-the other Doug

I'm getting impatient and frustrated too, but keep reminding myself that a) the rover team have NEVER let us down before, the dust-rippled floor of this crater is where Oppy will most likely end her days, so it's vital to get absolutely everything right as she approaches, and c) it's not MY neck on the line being in control of a multi-hundreds-of-millions-of-dollars spacecraft...

Whenever it happens, it will be worth it, then you'll see, there'll be a whole new dawn for Opportunity...

Click to view attachment

It may be...It may...though I'm not hysterical about it, somehow I'm expecting the conquest of Cabo Frio for the end of the week...

Given the nature and scope of the work at Victoria (70 m deep crater, 750 m diameter, 2.5 km circumference), I think it makes perfect sense for them to refine the software and fully test it before proceeding to the crater. In addition to the usual Mars strata studies, there is evidence of dynamic processes at work, such as the apparent gullies. It may be a while (a year?) before the "good science" from this massive & complex target is fully exhausted.

From common sense and things other people have said, there is a very low risk of losing the craft from the software update. You also certainly want the software fully tested and debugged before proceeding to VC. There is likely a much bigger spacecraft risk, once at VC, from a navigational error than from delaying the arrival by a week. Also a bigger risk, I would think, from inefficient exploration, since it may well be the case that the lifetime of the craft is reached during the exploration of the crater. Improving how rapidly targets can be reached & studied (touch & go versus go & touch).

As usual, once we learn more about what the rover team is thinking, we realize just how incredibly talented these guys are! Awesome work.

Doug and clt510 are absolutely right and I too am 100% confident that the JPL team does the right decicions as they always have in the past. As Stu said: they have never let us down before
On the other hand I also understand the apparent frustation and impatience of some of us after having travelled for more than 600 days and being now parked just one or two days away from the promised land.
I think it is just a natural and human thing to show some excitement, and, yes, impatience being so close to the goal after such a long waiting time ...
There has been an incredible tension built up during the last weeks, and I think it's just natural that
this leads to excitement and a bit elated (is this the right english word?) impatience :-)

Greets
Nir"are we there yet ? are we there yet ?"gal

I'm like the kids who always wants Dad to spend whatever it takes to get the car, clothes, toys, candy whatever I want.

Daddy, I want to see Victoria noooooow! Why are we waiting?!!

It is true that the rovers' handlers have always done the right thing. It's good that we are not the ones in control of the rovers.

Are we there yet?

As a public service, allow me to present some (faintly familiar?) alternative pictures to help sooth the twanging nerves in certain quarters...

Downlink is slow, too, no doubt. Weekly updates are here... http://voyager.jpl.nasa.gov/mission/weekly-reports/
Quite a few hours used, although I wonder if the hours used are not of vital importance at times when mars/saturn/venus/whatever are in different directions than the Voyagers.

New Images are in at exploratorium.

http://qt.exploratorium.edu/mars/opportuni...23P1151R0M1.JPG

Looks like the arm is done with it's experiments and I hope Oppy is ready to roll.