Once again on the bottom of the dunes

So far the wheel thats moved the most is the right front wheel, its now where it was before Oppy attempted to turn after the drive an sol 446. It appears that what they've accomplished so far is to reallign Oppy with its tracks. Hopefully we will see progress on both sides next time.

I dont think they're going to try and back out all the way down the trenches they churned on the way in - that churned material is softer and probably offers less traction that 'virgin' ground. I think, given the FR wheels 7 deg toe-out, they will do an arcing turn off to the left.

Doug

This is and enhanced version of poor-quality left/back wheel movements in both days (463 and 465); click to see it:

Is clear that there was further digging on this side, counterbalanced by very good movement of opposite wheel... I made also more complex animation containing the four wheels in both days (same idea from Doug project ), but I'm not able to publish it ! (ImageSack do not allow files>1M, can someone suggest best way?).

More info from The Steve.

New update from Steve Squyres:

http://athena1.cornell.edu/news/mubss/

The rover moved more than a centimeter in the expected direction during each maneuver, which was just the kind of behavior we were hoping for. (In fact, the motion was actually more than I was personally expecting to see this early in the game.)

He also said they will drive the wheels for 4 meters today. The last 2 have been 2 meter drives.

Ahh well, there goes my night again waiting for the new pics

Yeah, I see it. That's beautiful.

Wow. It's really moving. I had faith it would - but there is no substitude for reality. Well good, we'll be on the road again in no time. (maybe that's a little too optimistic)

The additional collapse is convincing me that the rover motion is causing it. I wonder what the rover team is making of them. Wonder if they find it significant...

New article in New Scientist

Optimism as Mars rover edges towards freedom

"NASA’s Mars rover Opportunity has begun its long march out of the sandy dune in which it got stuck on 25 April. Ground controllers have got it to move more than four centimetres since Friday - considered a big victory.
The space agency’s Mars rover team tried to recreate the conditions that halted Opportunity when it dug itself into a Martian drift. In Earth-based tests, engineers buried an identical rover’s wheels in a specially designed sandy mixture. In those tests, the rover’s wheels turned many times before it was able to pull itself out of the soil.
So on Mars, ground controllers expected soil to shift from the front to the rear of the rover, but they did not expect Opportunity to move right away. They commanded the wheels to rotate 2.5 times and as they turned Opportunity crept forward by 2.8 cm.
“We may have just made it a harder problem on the ground than what we see on Mars,” says Jim Erickson, rover project manager for NASA’s Jet Propulsion Laboratory in Pasadena, California, US. "

http://www.newscientist.com/article.ns?id=dn737

Opportunity progressed another 1.1 inches on the third drive (with twice the number of wheel rotations). Info from today's JPL MER web site update.

Ron Jones

I am following with much interest on how the MERS Team is doing a very delicate task to get out the Opportunity from the stuck sand. According to my vast experience of driving over Peruvian dunes, and I am well knowledge of different types of sand. The best sand are the ones has very fine grain and the worst are the ones has very coarse grain. The fine sand is the most compact and makes less trouble to navegate. Well, I think that the best solution for MERS to get out of "traicionero ceniza" must be done :

1) First, the most important is to look which way has incline down.
2) Second, follow on the same trail left by myself or by another robot is the safest. This way has less friction to advance than a new ones.
3) The wheels must rotate very slow but with all 6 wheels must rotate at the same time. It would be ideal that the MERS has the integral LSD so any one of wheels slips.
4) Don't stop if the movement is gainging the momentum.
5) Initially, moves very little forward and backward in order to compact the trail in order to help to start faster and gain the momentum of velocity.
6) It is much easier to navigate over dunes during night than the during day because the cold grain is more compact.

I look forward that my contribution has some worth.


Rodolfo

Good suggestions RNeuhaus, although on your points 4 and 5 I'd like to point out that whatever minute momentum Oppy has will not help here -- its wheels are completely gear-driven (i.e. there is no clutch), and it really moves extremely slow compared to any dune buggy here on earth...

Another day, another inch forward

made some animations of the progress so far:

Front:


Rear:


Also another thought that crossed my mind. Is it impossible to do more than one drive a day? I would imagine they could do if they used direct to Earth communication.

It would really help to get this job done quicker. Execute the first drive, wait for the result, and if it is looking ok, execute the next one.

dot.dk: What an excellent idea, to rock the animations back and forth. It's too bad we are not getting all of the 'in between' images lately, but I am getting the sense that Opportunity is making very good progress.

Kudos are due to the scientists and engineers on the team for doing what we all knew they could do when we dicovered Opportunity was in this predicament. Perhaps we should send them a case of Mars Bars when she is clearly out of danger.

If someone knows an appropriate JPL address that will actually get to them - I'll sort out a card or a little pressie or something

Doug

Great idea! Sadly I dont know an appropriate adresse - maybe Steve personally with a great thank for his current updates on the Cornell site.

I was thinking more getting a little garden trowel - painting it up with some gold spray paint - and sending it to the engineering team as a thank-you gesture for all the digging they've been doing in the mars-yard

Then again - last time I did anything like that was a little beagle 2 christmas card that I rendered to look like B2 stuck under snow from overyone at the old Beagle 2 yahoo group I started in '02. I dropped it off at the space centre here in Leicester, and Beagle was never heard from again Maybe I'm cursed.


Doug

Looks like it's animation time again

Warning! Slow loading....

Front Left:


Front Right:


Rear Left:


Rear Right:

absolutely love those animations, dot.dk !!

it's almost like live TV coverage from Mars

These are great animations indeed ! I don't like to see though that the rear wheels seem to dig in even deeper. Hope she doesn't get stuck on her WEB !

Only the right one seems to go a bit deeper, but would the nature of the Rocker-Bogie Suspension system not indicate that the middle wheel is rising then?

Don't think so: it'll stay in the same level at best. Rear wheel is sinking in, middle wheel will stay the same: WEB will get closer to the surface.....

I can't tell that the chassis sunk in at all. I wouldn't worry too much. When that wheel gets to the dirt pile that the middle wheel ahead of it has been churning up, we should see some lift.

On a side note, I suspect the people who study soil composition are having a field day with those 'animations' showing in great detail how the sand responds to the wheels on a minute by minute basis.

But the WEB ( and thus the Hazcams ) dont appear to be getting closer to the surface - so I think it's fair to say that perhaps yes - the middle wheels are rising a little

I've run all front hazcam driving all together as one long animation...

Front Left
http://www.unmannedspaceflight.com/doug_images/FL.gif
800kb

Front Right
http://www.unmannedspaceflight.com/doug_images/FR.gif
450kb

I'll keep adding to them, and make a .mov of all four corners when they're out

Doug

During my study physical geography (yeeeears ago) i did some work on mechanical properties of soil and my gut feeling says , that we all can be very happy about the fact that there are six seperately powered wheels ! I bet this stuff is even very hard (if not impossible) to traverse by foot !!

I look forward to this movie(s) by now

Thank you dot.dk too!

BTW, a little golden garden trowel could it be Maybe with a pack pudding powder in respect of our first impression about their sandbox

According to the last motion pictures, I am convinced that Opportunity will get out of stuck sand. It is approaching to the decline slope and also a more compact sand in which they will help to MERS B to come out of a situation with flying colours.

On that point. the motion must be keeping rotating enough distance until the MERS B reach to the point where the sand is flatter and more compact.

After the MERS is alive, I am doubting if the MERS is capable to distinguish by myself to the different type of sand in order to avoid that the future will happen again?

Rodolfo

Do we have any power numbers for Oppy? Surely sat there the power levels must be down, we prolly need to get a cleaning event on oppy soon.

I think I saw in one of Steve's reports he said something like 500w/hrs...

I could be wrong.

Great animations Doug!!! Nice to see that there are 3 Sol's worth of animations there (by the shadow movement)...

Looks like a very first operational rototiller on Mars, that's gotta be something for the history books...

Actually the news on that front is pretty good - From the Opportunity Mission manager Report on May 13th:
During sol 456, power engineer Eric Wood happily recognized a cleaning event. Winds removed some dust from solar panels and Opportunity's daily energy supply increased to about 650 watt-hours, from a recent range of about 620 to 630 watt-hours.

So it's well into the healthy range, not quite as sparkling clean as Spirit was after it's cleaning event around April 15th which took it to 800 watt hours but both are way above the critical 280 watt hours level which Steve Squyres has said is the level where they are likely to die.

JoeM

There *was* a cleaning event on Oppy some 10 days ago, and it helped a little (4-5%)

edit: Thanks helvick, it took a bit long for me to post it

WOW ! this is very interesting... so it seems that those cleaning events
are not only extremely rare "luck" events but do happen on a quite "regular" frequency (with the latest Spirit cleaning we had
at least 3 cleaning events in 1000 "Rover-Sols" !)

So this would imply that, given the "half live" time between cleaning events
and the average amount of cleaning by each event) is large enough, then we had "infinte" rover lifetime (as far as death by dust accumlation is concerned)

Does anyone have a link to a graph showing the power output level
against Sols (from the beginning of the mission) ?
Should be possible to do a power/life-time extrapolation from that, which
not only takes into account the slow degradation by dust accumulation but also
the "uplifting" effects of probable future cleaning events.

Working on it by pulling (very) approximate data from a bunch of sources mostly inspecting insolation graphs from various pdf's to try and estimate the seasonal variations.

Approximate data using Insolation chart from Netlander Virtual Prototyping, solar cell data from various sources but taking 900Watt Hours as the initial 100% capacity of the arrays, and working on 0.28% average degradation in Solar Panel efficiency per sol which is what I believe the assumed value was prior to MER. If anyone has better data sources I'd love to get them.

Rev 0 ugly Excel chart (image) attached showing my estimate of the expected power output of the panels on Spirit and Opportunity. This indicates that the rovers would have been expected to cross below the 400 watt minimum practical operational level at around Sol 160 and passed into the death zone below 280 watt hours at around sol 260.

I've plotted in the actual values I've gleaned from the mission updates however it's very sparse (about 5 randomly spaced data points for each rover) and needs some work. Then I extrapolated out from now using the original assumptions.

As it stands without any further cleaning events the rovers should still have enough juice to still do careful work at Sol 650+ for Opportunity and 690 or so for Spirit. Next southern hemisphere winter hits it's worst stage starting around Sol 890 which would be very nice to see.

A major dust storm would cancel all bets though - available power could drop rapidly below critical levels and we are in dust storm season AFAIK.

great work helvick !

your graph is exactly what I had in mind when I wrote the post above

So, with the frequency of "cleaning events" observed so far
(3 per 300 rover sols) there is reasonable hope to get at least one more
cleaning before the next critical 600-700 sol mark ...
-> really putting the 1000 sol mark in reach

Am I the only one thinking "damnit - if they get to 1000 sols, i'll have to rename all my folders"



As someone called it previously - perhaps we may even reach the S1K problem

Doug

Beautifull chart helvick, you must have way too much free time on your hands



gary

I probably do but don't tell anyone.

Seriously though I really get a kick out of the fact that it is now possible for a rank amateur to make an attempt at answering these types of questions. Once I saw Nirgal's question I wanted to see what the answer would be ( and why) and I was hooked.

Excel really isn't very useful for graphing things like this - anyone got any recommendations for any software that can make decent looking charts?

gnuplot ??

http://www.gnuplot.info/

I agree, the middle wheel must be rising.

After the 8 meter drive yesterday, how are we looking for today? Another 8 meter?

Another day, another cm

Here is an animation of all Oppys movement so far:



And from the back

wow thats a really awesome animation you got there would be nice if it would go a little faster though (not the animation just the overall progress of extraction for Oppy)

New JPL update.



Funny that yesterdays drive was only 2 meters and now they are pushing it for 12 meter

It will be very interesting!

That's pretty consistent at 0.5cm per metre so far.

I wonder if the lower limits mean they are worried about something or if they are just making sure it doesn't bury itself.

I was just playing around with the Rocker-Bogie suspension to see if I could mimic the rear right wheel sinking so much.

Got this:



Don't know if it is accurate in any way

Rear wheels are getting in deep
http://qt.exploratorium.edu/mars/opportuni...HHP1314R0M1.JPG

Yeah, but we are really making good progress now! We will be out soon!

The usual...

Front:


Rear: