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Posted by: fredk May 12 2009, 02:29 AM

We may have the same scenery for quite a while. From http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20090511a.html

Posted by: alan May 12 2009, 02:51 AM

I've been seeing this listed on the tracking site recently

01904 p2568.22 0 0 0 0 0 0 pancam_light_disturbed_soil_L6R1
01904 p2569.22 0 0 0 0 0 0 pancam_undisturbed_soil_L6R1
01904 p2570.22 0 0 0 0 0 0 pancam_dark_disturbed_soil_L6R1

Watching for signs of wind gusts?

By the way with the new found energy and the apparent decrease in activity why isn't the backlog of images being downloaded?

Posted by: RoverDriver May 12 2009, 03:06 AM

No. We are trying to gather mechanical properties of the soil under the wheels. Actually where the wheels are buried. We have observe from the RHAZ that although the wheels have churned up the soil pretty badly, the left side soil is bright in color while the RR wheel has churned up dark material. We believe the dark toned material could provide more traction than the light tone material. We will try to replicate the soil properties in the testbed, evaluate which strategies might work better and go from there. The situation is compound by the issue of high-centering. We are not sure we are high centered, but if we are not, we are cose to it. There is a single frame NAVCAM taken on sol 1870 which shows the terrain the rover is currently sitting. By comparing that NAVCAM frame with the NAVCAMS taken from the current location we are trying to figure out exactly where the rover is and determine if we are high-centered. The last fly in the ointment is that during the last executed drive (sol 1899) the LM wheel stalled. We do not have a cause yet, could be a rock stuck in the wheel well, could be bedrock underneath the wheel, could be an actuator problem.

This is a pretty big mess: embedding event + high-centered vehicle + stalled wheel. Since I have been asked to lead this investigation, you know why I won't be posting much during the next few weeks.

Paolo

Posted by: nprev May 12 2009, 05:17 AM

Oh, boy. Thanks for the update, and good luck, Paolo. We're rooting for you!

Posted by: alan May 12 2009, 05:45 AM

My guess for the location of the wheels.

Also identified are the original location of the rock that was flipped after being dragged and one that appears to have gone missing during all the churning.

ETA:
the pancam site has a color image of this location,
http://marswatch.astro.cornell.edu/pancam_instrument/images/False/Sol1367A_P2415_1_False_L257_pos_5.jpg
(about a third of the way up and a third of the way to the right from the lower left corner)

Posted by: Sunspot May 12 2009, 07:20 AM

Looks like some people think we may be here for the rest of the mission.

Posted by: RoverDriver May 12 2009, 09:47 AM

Good guess!



I believe this PANCAM is at a higher elevation than our current location.

Paolo

Posted by: RoverDriver May 12 2009, 10:33 AM

Hmm... maybe it is a language barrier, but I do not understand the point of your remark.

Paolo

Posted by: djellison May 12 2009, 10:49 AM

He's being the worst kind of pessimist...a pessimist who also thinks everyone else is pessimistic.

Posted by: alan May 12 2009, 01:24 PM

???

Do you mean it was taken from a higher position (its from the edge of Homeplate) or that the location is wrong?

Perhaps my explanation of the specific location in the image wasn't clear. I've circled what I meant in this image.



I can clearly see the two flat rocks which were run over during the drive on sol 1871(arrowed)

Posted by: ElkGroveDan May 12 2009, 01:24 PM

Here's a wild thought that would be more a later move of desperation. I'm not certain what kind of mass ratios we are dealing with but would it make sense to extend the arm and IDD to slightly shift the CG, and add to the traction/load on a preferred wheel or wheels?

Posted by: charborob May 12 2009, 01:59 PM

Seeing how the rovers are so vulnerable to getting stuck in soft ground, I wonder if that possibility had been taken into account when designing the rover wheels. With hindsight, it might have been better to equip the rovers with large balloon-type wheels, allowing them to "float", so to speak, over the sand. Maybe it would have caused other problems (storage space for big wheels, less traction?).
I can't help thinking about MSL, which seems to be equipped with somewhat similar wheels, although wider to account for the higher mass. I hope the experience gained with the MERs will be put to good use on MSL. We know there are sand traps on Mars. Lets hope MSL doesn't suffer the same fate as the MERs, getting stuck all over the place. (OK, the MERs aren't getting stuck all over the place, but you see what I mean.)

Posted by: MahFL May 12 2009, 02:00 PM

If anyone on the planet Earth can get us out, it is Paolo !

Posted by: SpaceListener May 12 2009, 04:18 PM

I still believe we can rescue Spirit. The things that must be studied carefully are about the relieve of the soil around the Spirit. We must take the advantage of the help of gravity direction to be unstuck. According to Alan's picture, I am not able to see precisely about the inclination of the surface. As the rule of thumb, the lower land, has softer soil than the higher ones. The picture has show that the left side, close to the slope, the surface is very smooth but I doubt it would be a firm soil.

Is Spirit capable to turn around by 90 degree to change the scape route toward left side (close to the slope) toward the Braun hill?

Maybe, lower soil, has another kind of layer, a firmer soil which might help to improve the traction?

Posted by: Stu May 12 2009, 04:18 PM

Is this roughly the right position?

http://cumbriansky.files.wordpress.com/2009/05/stuck.jpg

Posted by: nprev May 12 2009, 04:26 PM

You got that right!!! Go, Paolo!

BTW, back in Montana during my wild youth I nearly high-centered a few times in slippery terrain. IIRC, any sort of tilt along the longitudinal axis is a huge help in extraction (since you're normally pretty level along the lateral axis in this situation).

Posted by: Phil Stooke May 12 2009, 04:28 PM

"Is this roughly the right position?"

No, it's more like this:

Phil

Posted by: Stu May 12 2009, 04:35 PM

SO wrong to laugh at that Phil, but I couldn't help it. You're a very bad man!

Posted by: Phil Stooke May 12 2009, 04:50 PM

A very, very, very bad man! (waggles finger)

Phil

Posted by: nprev May 12 2009, 05:27 PM

Well, if worst comes to worst, just land MSL nearby & program the SkyCrane to hover over & yank her out after it drops off MSL!

Posted by: Stu May 12 2009, 05:33 PM

I think you're confusing MSL with Thunderbird 2...

Posted by: Oersted May 12 2009, 05:57 PM

I suggest a new thread called "Getting unstuck in West Valley" or something to that effect... - This will take a while.

Posted by: imipak May 12 2009, 06:56 PM

From an http://www.whittierdailynews.com/news/ci_12329089 Tweeted by MarsRoverDriver:

MahFL @390 thirded; you posted the words out of my head. Stu - my impression (FWLIW!) is that the front wheels (near side in your image) is a little less deeply embedded, and that the site's a few cm further away to the south. Been wrong before, YMMV, etc.

ISTR that after the first day or two of trying to back Oppy out of Purgatory didn't work, things looked pretty scary. In retrospect, that was mostly because it was the first time it'd happened, and the way out wasn't immediately obvious. Hopefully, the same applies now.

Posted by: djellison May 12 2009, 07:45 PM

Now I wish I'd made building a 1/4 scale mobility model my Winter '08-09 project rather than my project for NEXT winter.

Posted by: RoverDriver May 12 2009, 07:56 PM

I meant to say that it looked like this pancam was aimed at a higher elevation, with the PMA aimed at an area that is visually above the NAVCAM.

What Sol is this? [edit: never mind, I see what sol # it is. Thanks!]

Paolo

Posted by: RoverDriver May 12 2009, 08:03 PM

The IDD is about 2-3 Kg and about 1m long, the rover is about 200Kg. You do the math. :-(

Paolo

Posted by: RoverDriver May 12 2009, 08:06 PM

Thanks for your trust in my capabilities, but I have assembled a team that will actually do the work. Since we will be doing some testbed analysis, you won't see much changes in the scenery for a while, don't interpret this lack of mobility activity as unsuccessful motion.

Paolo

Posted by: RoverDriver May 12 2009, 08:13 PM

Brief description of the rover attitude:

1) the rover is aligned more or less north-south (front of the rover north)
2) the rover is on a slope about 10-12 degrees, left side of the rover is lower than the right side
3) pitch is almost zero

The soil under the left side is cohesionless, the soil under the right side seems to provide more traction.
The two middle wheels are only partly embedded, the RF is on top of the surface, LF, and rear wheels are fully embedded.

Turning in place was tried (CW) but was unsuccessful. We might try to revisit this technique.

Paolo

Posted by: alan May 12 2009, 08:15 PM

The image was taken as part of the West Valley pan on sol 1367
http://marswatch.astro.cornell.edu/pancam_instrument/1366A_WestValley.html
http://marswatch.astro.cornell.edu/pancam_instrument/images/False/Sol1367A_P2415_1_False_L257_pos_5.jpg

Posted by: RoverDriver May 12 2009, 08:16 PM

Roughly, yes. The roll of the rover is not very accuratly represented as well as the precise state of each wheel, but the position itself is quite accurate.

Paolo

Posted by: RoverDriver May 12 2009, 08:17 PM

Thanks. This exactly the kind of posting I'd like to see. THANK YOU!!

Paolo

Posted by: lyford May 12 2009, 08:27 PM

Pardon my ignorance, but what does the term "high centered" mean? Is it referring to center of gravity? A 4WD phrase? Both sides are equally dug in???

Posted by: nprev May 12 2009, 08:35 PM

"High-centered" usually means that the vehicle's center of gravity is being supported on something other than the drive surfaces, so there's little or no traction, Lyford.

Paolo, it's good that there's some significant lateral slope. Are there any transducers or some indirect means to measure how much of Spirit's weight is resting on the wheels? That would be good to know for strategy development.

Based on your description of the situation, if it was me in a truck or something I'd gun it forward, expecting the left wheels to slip & hoping that the right wheels would grab enough to spin me downslope (leftwards) & pick up dual traction again.

Posted by: HughFromAlice May 12 2009, 08:37 PM

From one who has been bogged in remote places many times during their driving career, I would say thinking it through and - above all - patience pay high dividends!!! I'm sure that they'll test, retest and reretest....... over many many weeks if necessary.

Paolo, besides getting thermoses of strong black coffee air freighted to your team, is there any small thing at all that UMSFers could do that could be of support? (Like the v useful posts above of exactly where Spirit was bogged - or some thread similar to the Drivability Analysis etc.) Very frustrating to have to just sit here while the wheels spin!!!!

Posted by: marsophile May 12 2009, 09:07 PM

This is maybe grasping at a straw, but is the soil traction affected by temperature? Is there any reason to think a night move, when it is colder, might have better traction?

Posted by: RoverDriver May 12 2009, 09:19 PM

That is correct. Sorry for using terms that are unfamiliar.



Not that I know of. The rocker-bogie system since it is passive is an indirect measurement, but it is affected by the mechanical properties of the soil.



A car or truck is not really representative of the type of motion we have on the rover. It is mostly a sequence of quasi-static moments rather than a dynamic event.

Paolo

Posted by: nprev May 12 2009, 09:23 PM

Got it; I used the truck analogy for illustration only.

What I was thinking was something like a 30 sec run on all drive wheels (forward or backward!) Even churning the soil on the left side provides some impulse via reaction. If you can get the nose to swing to the left enough, you're probably home free.

Posted by: nprev May 12 2009, 09:30 PM

Here's another unsolicited silly idea: Can you turn the 3 operable front & back wheels 90 deg with respect to the lateral axis of the rover & try to translate it to the left (not a spin, all driving the same direction)? That might drag you clear of whatever's presumably underneath & reseat the wheels.

Posted by: RoverDriver May 12 2009, 09:33 PM

Nope. The max is 60deg, we tried to turn them 30deg and drive forward (1894-1899) and made some (slowly diminishing) progress.

Paolo

Posted by: SpaceListener May 12 2009, 09:36 PM

A question, when MER landed on Mars, its six wheels were kept inside. I wish I would have seen the movie on how MER unstowed their six wheels before rolling out from the lander bag to see whether the below idea would be feasible.

Depending upon to its technical characteristics, is possible to perform stow the 2-4 or 6 wheels until its belly touches on the surface and again perform to unstow the wheels very slow trying to turn around somewhat so that the wheels can pose on better firmness soil?

Posted by: Stu May 12 2009, 09:37 PM

Thanks Paolo, appreciate that. It was just a thrown-together thing, so glad to know I wasn't too far out.

All the best to you and your team as you start looking at this. Hard days ahead of you, to be sure, but you're the guys to get our gal free.

Posted by: nprev May 12 2009, 09:40 PM

Hmm. How about rocking it? That would be a 60 deg all wheels right short move going aft, followed by 60 deg all wheel left going fwd, repeat a few times & see if her nose begins to point downslope.

(BTW, thanks for your patience with my amateur suggestions, P; you're busy, and your replies are kind, but no worries if you got better things to do! I'll post whacko thoughts as I get them just for fun.)

Posted by: BrianL May 12 2009, 10:02 PM

Paolo, could you move your seat forward a bit? I don't think nprev has enough legroom back there.

Posted by: nprev May 12 2009, 10:04 PM

...fortunately, my legs are retractable!

BTW, Paolo, don't forget to adjust your rear-view mirror before backing up!!!

Posted by: Oersted May 12 2009, 10:34 PM

I wonder if the arm could usefully push against the ground in any way, to take weight off wheels? Would that be helpful? That would obviously be a last-ditch (no pun intended) effort. The arm is pretty strong and the rover weighs less on Mars...

Posted by: fredk May 12 2009, 10:47 PM

Here are a couple of anaglyphs showing our current location, above the clump of rocks near centre of each image (refer to the previously posted maps for our precise location). First is navcam from sol 1870, second pancam from HP on sol 1367:

You can clearly see how the ground slopes downwards on the west (left) side of the rover. If only we could make it a bit in that direction and let gravity help pull us out from there...

Posted by: RoverDriver May 13 2009, 12:36 AM

This is a variation on the theme of turning in place and I will keep it in the list of things to try. The immediate reaction is that I would be concerned of digging the wheels in with this type of back and forth motion, but the sandbox testing will tell us something. Thanks.

Paolo

Posted by: nprev May 13 2009, 01:46 AM

You're welcome! Hope it helps; looks like the main idea is to precess the nose downslope somehow.

Re wheel digging: Any idea if those nasty soils on either side compress worth a hoot? If so, then rocking on a patch might make it a bit firmer.

Posted by: Tesheiner May 13 2009, 05:44 AM

Good luck with the testing, Paolo. Fingers crossed.

They are locked in place. AFAIK, impossible to stow the wheels.





Already answered on yesterday posts.

Posted by: climber May 13 2009, 08:48 AM

Crazy idea, but well...
On Earth, to get free from this situation, we'll put "something" under the weels to get back some traction.
Is there anything we could drop under a weel? (don't blame me for the idea, I try to be creative )

Posted by: djellison May 13 2009, 08:57 AM

Already mentioned was perhaps pushing rocks toward the low traction wheels to help them. Sand ladders would be mighty usefull right now.

Obviously none of us can drive this thing - but what have we not thought of yet.

- Soil analysis - how does this lot compare to previous 'got stuck' moments like Tartarus and Purgatory.
- Drive strategies - what might the MER guys not have thought of.
- Every ounce of imagery of this spot - I think this site will be in images taken from the top of home plate (I found the back of that 'skull' from a pan taken up there)
- Specific things that the rover could try that are not crazy (or maybe some that are)

Get creative, and we might get out!

Posted by: djellison May 13 2009, 09:03 AM

I THINK - the current location is in here - http://marsrovers.jpl.nasa.gov/gallery/all/2/p/1367/2P247721014EFFAWCCP2415L2M1.HTML from 1367

Posted by: jamescanvin May 13 2009, 09:28 AM

Yeah Doug that is the same one as the colour image Alan posted.

To get a third perspective I went to Sol 1389 (just after Tartarus). No pancams unfortunately but there is a navcam pair

http://marsrovers.nasa.gov/gallery/all/2/n/1389/2N249673612EFFAWRCP1965L0M1.HTML

Above the LGA (I think)

Right eye

http://marsrovers.nasa.gov/gallery/all/2/n/1389/2N249673612EFFAWRCP1965R0M1.HTML

(Above the HGA in this one)

Posted by: djellison May 13 2009, 10:18 AM

For those pondering IDD shoving/pulling etc.

http://www.esmats.eu/esmatspapers/pastpapers/pdfs/2003/fleischner.pdf

Page 5 includes torque values for each actuator. The wrist/turret are much much weaker - but the Elbow can manage 20 Nm force, it can handle 40 Nm static, the Shoulder's two motors about 45 Nm.

That would suggest, to me, that if you could brace the IDD into the ground, you could apply, say, 30 Nm at the shoulder without getting near the static limit of the elbow. You would have only about 60 N of force at the IDD attachment point though - as each part of the arm is about half a meter long.

The rover, at 185kg, has a total force from gravity of about 697N. So the arm would only ever be able to take about a tenth of the weight of the rover.

How that might be turned from a 'lifting' force into a 'pushing' force, and what impact that might have, is beyond my feeble engineering mind. I get the feeling the ISIL will be phoning in for extra IDD actuators if they go down this road - seems like an efficient way of burning them out.

Posted by: Stu May 13 2009, 10:28 AM

So, what you're saying, Mr Data, is that that won't work..?

Posted by: Oersted May 13 2009, 10:36 AM

Yes, Doug, that was what I was thinking of, not just using the weight of the arm, but use the arm as a pushing force. Well, that doesn't seem to give us a lot, from the calculations you presented (which do take account of Martian gravity I'm sure).

An even more hare-brained idea then: Can we get traction out of the arm? I.e. by driving OVER the IDD? - If the wheels get a good grip on the IDD and the IDD is lodged against the ground then just maybe... Yes, doesn't sound nice and I hope we won't ever have to contemplate that seriously!

Of course, pushing rocks under the wheels with the IDD, as suggested by others, is a better idea. Just want to get all possibilities on the table, or rather OFF the table!

Posted by: Stu May 13 2009, 10:54 AM

Maybe Spirit just needs a lift from some passing natives...

Posted by: djellison May 13 2009, 11:23 AM

Paolo mentioned that driving motion and IDD motion at the same time is impossible - so driving over the IDD wouldn't be possible.

As for Stu's picture, it is my long held opinion there is no situation that can not be resolved with a significant quantity of explosive, or a significant number of ewoks.

Posted by: nprev May 13 2009, 11:42 AM

Heck, just give me three Saturn V launches, 200 kegs of beer, 50 tons of beef jerky, a little O2 & a winch, and I'll get 'er done. <grunt><hitches belt>...

Posted by: Astro0 May 13 2009, 12:37 PM

Before we go calling on Jawas or sending nprev to Mars full of beer and jerky, it'd be nice to have as much information about the situation as possible.

I'd like to get a look 'under' the rover. We can't get a 'clear' view with the MI on the IDD, but what about shadows.
With the extra power that Spirit has available, would it be useful to look at the shadows she's casting late in the day and see what clearances Spirit has from the ground and a better idea of the current position of the wheels? Where is the sun setting right now at Gusev?
With our knowledge of camera views, angles, distances, how much information can we come up with at UMSF about the situation on our own?
Paolo has been very generous with the answers he has given so far, but he and the rest of the team are going to be busy for quite a while.
Working out as much as we can ourselves would be an excellent exercise - and as Doug said, we should 'get creative, and we might get out!'
We don't have our own rover or a Mars yard to test our ideas, but could we come up with another way to test strategies?

This could be lots of fun...

Posted by: alan May 13 2009, 12:47 PM

Spirit is in a valley she probably will be in shadow before the sun gets low enough to shine under her.

Posted by: nprev May 13 2009, 12:54 PM

Well summarized, Astro0.

I for one am very curious about the "high-centered" feature of the problem: What is she hanging up on? Is it a pile of 'plowed' sand, or a little hummock, or...? Need to understand that to derive a solution since it could make a big difference in driving strategies.

Posted by: Astro0 May 13 2009, 01:06 PM

I don't think that we are that far between Tsiolkovsky and HP to prevent some longer shadows.
See Tesh's http://www.unmannedspaceflight.com/index.php?act=attach&type=post&id=17789 for Sol 1871 (where Spirit is right now).
Depends on where the sun is setting and Tsiolkovsky isn't that high. Spirit can see over it.
I think that any shadows will provide more information to us.

Posted by: RoverDriver May 13 2009, 01:12 PM

Tried. Rover is oriented North-South (front towards North), and left side lower than the right side (negative roll) about 10-12deg (will know the exact angles in a short while). Therefore we need to take images at sunrise, the ideal time is 6:00-6:10. We got 5 NAVCAMs on the morning of sol 1902 between 5:50 and 6:13 (IIRC) and today (morning of sol 1905) we should have 5 more captured after this set. I have not seen these last 5 images but It looks like the sun is blocked by the top of Home Plate at the time the Sun would be aligned with the belly pan. Sigh.

Hope this helps.

Paolo

Posted by: RoverDriver May 13 2009, 01:14 PM

Listed under the category "last chance". Hopefully it does not come to this.

Paolo

Posted by: RoverDriver May 13 2009, 01:17 PM

Wow! You have sharp eyes! Thanks!

Paolo

Posted by: Astro0 May 13 2009, 01:30 PM

RoverDriver (Paolo) said: 'Tried'...'Sigh'.

Damn! We were filming a documentary with the BBC today at the Canberra DSN and couldn't get the sun in the right place for the right shot either.

Seems like it will come down to angle of the vehicle and depth of the wheels and some educated estimates of the rocks and surface seen in earlier views.
It would be nice to model this somehow - virtual, graphical or physical.

Posted by: marsophile May 13 2009, 03:31 PM

How much force is the wind exerting on or under the rover deck? Is this a factor in the traction?

Any possibility the RAT or brush could clear a path through the pile of dust?

Posted by: fredk May 13 2009, 03:52 PM

I really liked the low sun angle shadow idea, but I see how HP blocks the morning sun. But the sun should set in the WSW as we're near the solstice. (Azimuth around 245 degrees if I'm correct.) So sunset would be in this navcam frame:
http://marsrovers.jpl.nasa.gov/gallery/all/2/n/1891/2N294249010EFFB1C6P1961R0M1.JPG
The bellypan is about 1.25 metres below navcam. The top of Tsiolkovsky, the ridge in that navcam view, is about 20 metres away. That means the ridge would appear only about 3.5 degrees higher from the bellypan than from navcam. So the Sun should appear only about three degrees high when it sets behind the ridge from the point of view of the bellypan.

So even with the 10-12 degree roll angle of the rover in the wrong direction, sunlight can enter the gap under the bellypan at an angle of only 13-15 degrees relative to the plane of the bellypan. In addition, the sunlight would enter the gap not directly west-east, but at an azimuth of about 25 degrees relative to west-east. So the sunlight can enter the left side of the gap and emerge at the front (or enter the back and exit the right side). That means it has less distance to travel under the pan than the full gap width, so is more likely to emerge and give us information with shadows.

So could it be that we might still get some useful images of sunset shadows? Admittedly it depends on what exactly the height and shape of the ground is below the rover. But that's what we want to determine. So mightn't a null result (no sunlight passing through the gap) still give us important info? Ie with a null result we could say something like "the ground under the rover must be at least x cm high"?

Posted by: Tesheiner May 13 2009, 04:10 PM

I think it's worth a try.

Here're some of the navcams from sol 1902:
http://qt.exploratorium.edu/mars/spirit/navcam/2009-05-10/2N295193949EFFB1DNP1982L0M2.JPG
http://qt.exploratorium.edu/mars/spirit/navcam/2009-05-10/2N295194659EFFB1DNP1982L0M1.JPG
http://qt.exploratorium.edu/mars/spirit/navcam/2009-05-10/2N295195012EFFB1DNP1982L0M1.JPG


I think it's on the "last chance" category too.

Posted by: hendric May 13 2009, 04:43 PM

Could a shiny and rounded side be put onto MSL's robotic arm to allow looking underneath it? Maybe someone could suggest it to Exomars too?

Posted by: algorimancer May 13 2009, 04:50 PM

I believe that traditionally the mirror goes on the toe of the shoe . Not so effective with wheels, though.

Posted by: fredk May 13 2009, 05:16 PM

Back on sol 373 Oppy's front hazcam caught an interesting reflection from a part of the IDD:
http://marsrovers.jpl.nasa.gov/gallery/all/1/f/373/1F161306157EFF42DIP1144L0M1.JPG
What about maneuvering Spirit's IDD to use it as a mirror to try to image under the belly?

Posted by: fredk May 13 2009, 05:23 PM

Or, for that matter, what about using the MI to directly image under the belly, if it can be maneuvered in such a way? Of course the focus would be terrible, but we might be able to still get a rough idea of how close we are to high-centreing. Especially if the background beyond the rover is bright, and foreground (ground under the rover) is dark - we could distinguish the foreground in silhouette against the background.

Posted by: algorimancer May 13 2009, 05:34 PM

Actually a bit of deconvolution might correct the out-of-focused image. I've had great results with a couple of focus-correcting software apps. But can the IDD face backwards? Using it as a mirror will likely work just fine.

Posted by: djellison May 13 2009, 05:47 PM

MSL's MI can pull focus

Posted by: maycm May 13 2009, 06:38 PM

Couple of thoughts….Not quite in the category of pushing rocks but perhaps the arm can push some soil/sand under the wheels. Easier perhaps? Alternatively will simply moving the arm into an unusual position change the centre of gravity enough to mitigate some of the “high centering”?

Posted by: nprev May 13 2009, 07:01 PM

Hmm. Amplifying on your COG shift idea, Maycm, what else on the MERs can still articulate? I don't know if the HGA can provide any significant mass offset. Can the Pancam mast still retract/extend? (I sincerely doubt it, but have to ask.)

EDIT: BTW, ElkGroveDan first posted the idea of using the IDD http://www.unmannedspaceflight.com/index.php?s=&showtopic=5999&view=findpost&p=140291. Suggest that everybody read (and re-read!) this entire thread as a brainstorming aid.

Posted by: SpaceListener May 13 2009, 07:53 PM

My best guest, analogy, the Pancam/Navcam mast cannot be stowed as the wheels. It is fixed after it is unstowed.

The question that I have is about the properties of soil around Spirit. How can be a big difference of firmness of soil between left (west) and right (east) side of Spirit. The channel which Spirit is traveling was maybe a river where the water from higher lands were flowing toward the South. The soil of the channel, specially on the left side, close to the hills Tsiolkovsky would have a regolith of silica sand (reacted by the treatment of water) would lose the firmness faster if it is cracked by the wheel action.

One of the last hope is that below of regolith (10, 20, 30, ? cms) might be a bedrock in which the rover's wheel will gain the traction again after sinking the wheels after a long rolling. Yes, I believe it since I don't think that the soil would be loose after the regolith (a zone where the land have already undergone any kind chemical process, any ashes, sand deposition) For that, the only way is to use the turret to find out about how deep is the regolith? I doubt it but it is worth to ask it anyway.

The Freddy idea of using the IDD as an mirror is a genial ones.

Posted by: Tesheiner May 13 2009, 08:49 PM

My 2c: because there's more pressure on the left wheels due to the 10º roll?

Posted by: dot.dk May 13 2009, 09:08 PM

Maybe some kind of "tank mode" driving could help? Moving back on the right side and forward on the left. Or Vice versa

Posted by: HughFromAlice May 13 2009, 09:47 PM

Like you Doug. I have to admit to having a weak - if not feeble - engineering mind! So take this with a pinch of Home Plate salt.

But, as a last ditch option why could this not be a possibility? To get out of a bog isn't necessarily about applying huge forces - I've even seen a few people push a big truck out of a bog which suggests to me that the difference between being bogged and getting enough traction to get out can sometimes be very small - sort of on a knife edge.

So, if the weight distribution of the wheels - and the max tractive effort that can be applied by each wheel at the point where wheel movement would acheive no forward movement at all - could be worked out, couldn't the IDD be used to slightly redistribute the weight of the rover so as to increase the total applied tractive effort of the whole vehicle before the likelihood of total slipping occurs? Such as, more weight on the black soil etc. Hopefully this would be within force level the IDD could handle. Could be that just a few percent would make the difference? It would probably only be for a few centimeters until some percentage level of motion to slip was achieved under 'normal' conditions.

The first movement in getting out of a bog is usually the most important one!

Posted by: climber May 13 2009, 09:51 PM

Another idea regarding taking pictures. Can't we use the HGA to reflect the sun in a poorly illuminated area? (I'm thinking of the weels inbetween solar panels)

Posted by: nprev May 13 2009, 10:26 PM

Paolo answered earlier in this thread that they're already tried to rotate in place with no success. Also, ElkGroveDan was the first to suggest using the IDD to shift Spirit's center of gravity, and Paolo responded by providing numbers showing that its mass was insufficient to do so.

(Just providing a partial synopsis re proposed extraction methods to date to encourage brainstorming!)

Posted by: stevesliva May 13 2009, 10:29 PM

I'd guess that this is what's been referred to a few times as "turn in place." Or isn't is? With wheels that can't turn 90 degrees, I'd guess tank-style is the only way to turn in place. But I don't know. One could envision pivoting around unmoving center wheels if the front and back ones did turn 90. They would drag, though.

Posted by: SpaceListener May 14 2009, 01:24 AM

Yes I agree it. .

What I am afraid is that the soil which Spirit is sitting has a similar sort of composition in all sides. The soil firmness of left side (face toward the north) is already broken due to as you have said. I suspect that around soil might have some fews (4-8 cm) of deposit sand caused by eons of years. The deposit sand has already covered the other layer of soil, basalt silica of the ancient water-rich environment. This soil has a peculiar property that it does not get as bond as the other kind of soil. So it is like to sugar. That is driving crazy to the wheels.

A similar type of sand on Earth, the car is not able to get out unless the tire is deflated, put something (table, stone, etc.) below the tire or get help of pulling from other car.

Meanwhile the position of Spirit is not at the center of the gravity but inclined between 10-12 degree on the left wing (facing to north). That means, when it tries to roll, the wheels on the left wing will sink more than the right wing ones if all wheels rotates at the same time. I am not sure about the height of Spirit's belly to the surface. Maybe between 30-40 cms. Thus, I hope that below of basalt silica must have some kind of much firmer soil not so deep to permit Spirit to grip and advance.

At this point, I still don't know if the Spirit has a nice type of slippage blocking on every 6 wheels like of some sophisticated 4x4 trucks. If it is true, the traction would be fantastic by by trying not to slip any wheel and at the same time any wheel trying to grip the surface whenever as much as possible. Does Spirit have that capability? I am afraid it is not. The slippage capability of Spirit will be done manually, as an example, 10 revolutions on the right side and 2 revolutions on the left side. A complicated sequence of timing programming. Needs a good doses of gut feeling to calculate it!

All at all, the most important is to evaluate the surface (properties, inclination, stones, etc.) not around Spirit but up to 10 meters of radius as an example).

Finally, I wish you have a plentiful time and calm during the lab testing studying all possible options. Let God save our dear lady.

Posted by: fredk May 14 2009, 01:50 AM

I don't agree - I think the white (silica?) soil is mostly on the left (west) side of the rover. If you look at the view to the north:
http://marsrovers.jpl.nasa.gov/gallery/all/2/f/1899/2F294958090EFFB1DNP1254L0M1.JPG
you can see no sign that any white soil has been exposed in the right tracks. But looking at the right wall of the left tracks, the white soil looks like it's just below the surface on the left tracks. Similarly the rear right wheel has dug in but there's no sign of white soil around it.

Posted by: RoverDriver May 14 2009, 02:06 AM

I have people working on that. It might also be that we will end up imaging the belly with the MI...

Paolo

Posted by: RoverDriver May 14 2009, 02:10 AM

When I simulated the Sun ephemeris it did not look like it was even remotely possible to have the Sun cast a visible shadow at sunset. Sigh.

Paolo

Posted by: RoverDriver May 14 2009, 02:12 AM

I doubt that the MI electronics where the reflection was seen is still shiny enough to allow a reflection to be seen. And if I need to unstow the IDD I might as well take an MI.

Paolo

Posted by: RoverDriver May 14 2009, 02:14 AM

If you can suggest a kernel filter, I am all ears. I used the Gimp to apply a bit of unsharp mask on the LF wheel MI image from Opportunity and got something, but still not too clear. If you have any SW and are good at deblurring, email me the image (or if there is any interest post it in the Opportunity side).

Paolo

Posted by: RoverDriver May 14 2009, 02:18 AM

It has been suggested already. A request, if I may. Before suggesting a solution, read other people's comments, it might be that your idea is already out. If you suggest an idea that is similar to one already posted but think there is a fundamental difference explain the difference. Thanks!

Paolo

Posted by: RoverDriver May 14 2009, 02:22 AM

I don't think we have room to sink that low, we would be high-centering, and moreover the added drag from all the soil in contact with the rover would not allow much progress.

Paolo

Posted by: tedstryk May 14 2009, 02:22 AM

I have some deconvolution filters I use. I am a bit lost here....has an MI sequence been taken or is it just being considered?

Posted by: RoverDriver May 14 2009, 02:24 AM

I was told that there a significant difference between the soil under the left wheels and the soil on the right wheels. The roll value does not help either but was told that the main reason is the soil type.

Paolo

Posted by: RoverDriver May 14 2009, 02:25 AM

It is on my list, but it would be less efficient than a turn in place, and that one did not work that well.

Paolo

Posted by: RoverDriver May 14 2009, 02:32 AM

Good point. My instinct tells me that by moving the CG we might alter the traction for each wheel and that would change the position of equilibrium a bit (=position of no more progress), but not significantly change the result. But I will see if I can test this.

Paolo

Posted by: RoverDriver May 14 2009, 02:33 AM

It has been taken on OPPORTUNITY Sol 1882 IIRC. The wheel in question is the LF.
See: http://www.unmannedspaceflight.com/index.php?s=&showtopic=5940&view=findpost&p=140166
Paolo

Posted by: Fran Ontanaya May 14 2009, 02:57 AM

On putting sand under the wheels to get traction, maybe the LF wheel could be floated right where it is by repeatedly lifting the rear side a bit with the arm. A small amount of sand could get under each time and compact as the weight is released on it again.

Posted by: RoverDriver May 14 2009, 04:28 AM

I read and re-read this passage many times but I do not understand it. Why lifting the rear of the vehicle would result in LF wheel to raise? And how would I raise the rear with the IDD (which is in the front)? By extending it forward? Is there a typo some place?

Paolo

Posted by: nprev May 14 2009, 06:28 AM

Paolo (and, Fran, please correct me if I'm wrong), I think he's suggesting compressing the soil under the LF wheel by repeatedly pressing on it & thereby building a little base of compacted sand as new stuff trickles underneath the wheel between downstrokes.

This hearkens back to an earlier question: How compressible is this stuff (either side), anyhow? If it's sufficiently fine-grained, then an idea like this has some merit; flour gets pretty rigid under pressure. Unfortunately, it also appears to be relatively deep.

Posted by: djellison May 14 2009, 07:28 AM

GIven the max static torque of the wrist and turrent, I'm not sure significant compacting would be possible anywhere you might want it to. You could line up the joints in such a way as to pass it down to the elbow and shoulder in some specific orientations I guess.

Posted by: Tesheiner May 14 2009, 08:00 AM

All this discussion about these "extreme" uses of the IDD raises another question.

I suppose that IF the IDD is used to e.g. lift the wheels, move objects, drag the rover..., its science instruments will finally become damaged / unusable. So, what's the best compromise? A stationary rover with an usable IDD or an unstuck one with a damaged IDD?

Posted by: djellison May 14 2009, 10:42 AM

I would use the RAT as the 'blunt trauma' IDD instrument - I THINK that should keep the others REASONABLY safe.

Posted by: climber May 14 2009, 11:13 AM

Kind of compromise answer: once we have no more need of te IDD at the current position, we'd better become a rover again.

Posted by: RoverDriver May 14 2009, 12:13 PM

That is a very sensible comment. It would probably more productive for the moment to concentrate on ideas that do not involve the use of the IDD.

Paolo

Posted by: Poolio May 14 2009, 12:32 PM

Fran and nprev brought up trying to compress the sand beneath the wheels...

If this were in some way advantageous, could compression be achieved by vibrating the rover? I'm refering to the method used on Opportunity to try and shake dust free of the Mini-TES. You could vibrate to compress, then advance a couple centimeters and repeat. Perhaps progress could be made that way.

The idea of compressing the sand makes me uneasy though. You may gain some traction, but you could also sink her further into the sand.

Posted by: Fran Ontanaya May 14 2009, 01:15 PM

Ah, yes. I meant the front side. -1 spatial sense for me.

I was thinking in something like the Brazil nut effect. Raising a little bit the LF wheel and dropping it many times so sand from the sides is dragged under it and compacted.

Posted by: Juramike May 14 2009, 01:53 PM

[Ignorant, flailing idea time]
Trying to simulate a 4x4 where all wheels are locked (coordinated)...
...would it be possible to vary the current to each wheel such that it is inversely proportional to the amount of slip?

Would that be useful?
(or has this already been done?)

Posted by: RoverDriver May 14 2009, 02:41 PM

We typically "lock the differential" so to speak since there is one motor per wheel. We can control each wheel independently but that has to be preprogrammed. We cannot control the wheel torque dynamically tho. For that we would need to sequence one command, downlink the telemetry, see the wheel current (proportional to torque) and change the parameters accordingly. That would be slow, but possible.

Paolo

Posted by: SpaceListener May 14 2009, 04:56 PM

Good and thanks for the pointing. That is a puzzle!
It is very difficult to differentiate the type of soil if it is already buried by ashes, and sands deposition. It seems like that on left track had passed a thin flow of water...

Posted by: charborob May 14 2009, 05:18 PM

Better still, how NOT to get stuck. On the other hand, I suppose there are situations on Mars that even the best rover design cannot anticipate.

Posted by: Burmese May 14 2009, 06:32 PM

* Imagines some buyer at a large west coast swimming pool supply manufacturer who had the foresight to have Yahoo send him an alert any time the words 'stuck, 'sand', and 'Mars' turned up in the same news article yelling 'Eureka!' *

Posted by: alan May 14 2009, 09:55 PM

Starting a 360 degree pan?

01906 14:07:14 p2279.10. 1 0 0 0 0 0 12 pancam_Calypso_pan_col1_1x3_L257R2

Posted by: nprev May 14 2009, 10:02 PM

This is probably a "duh" question, but still having trouble visualizing the "nearly high-centered aspect", even after looking at the excellent photos & models posted. Is she dug down far enough at the wheels that her belly is nearly resting on the surface near the crest of this little ridge? I've been thinking of a pile of rocks and/or sand underneath, but not sure if that's correct.

Posted by: RoverDriver May 15 2009, 12:37 AM

There is a little ledge, possibly delimiting the bright toned material. Near the ledge there are some rocks that generate some elevation on top of the ledge. The LF, RR, RL wheels are buried completely. The LM and RM wheels are buried about to the hubs. The RF is on top of the dark-toned material. Since most of the wheels are buried the bottom of the REM is quite close to the surface. Those small rocks near the ledge are the cause of the high centering.

Paolo

Posted by: nprev May 15 2009, 01:07 AM

Thanks, Paolo; that helped!

I confess that I don't know what the REM is (rear electronics module?); is it part of the WEB? Anyhow, if the REM can take a weight load & rest on the rock underneath, here's yet another silly last-resort idea: Spin the R wheels and dig down on the right side till she bottoms out partially (keeping the left wheels seated, such as they are), then try another spin-in-place to the left using the rock as a pivot point. Hopefully, Spirit would slide off the rock (to the present aft direction) with her nose pointed more or less downslope.

Not a first-choice strategy by any means, and there are two major assumptions involved, but just throwin' it out there.

Posted by: Oersted May 15 2009, 01:32 AM

Let's look on the positive side: we're digging one heck of a trench The ever-ambitious Spirit rover wanted to become the Spirit digger, exploring the hitherto unknown nether-regions of Mars.

Posted by: RoverDriver May 15 2009, 03:04 AM

You almost got it. ROVER electronics module, but I meant the WEB (warm electronics box).



Yes it can! It is pretty robust and eve in case of puncture there's about 1" of space before hitting anything.

Paolo

Posted by: Shaka May 15 2009, 05:48 AM

Grazie tante, Paolo.
Right now you're keeping a lot of us sane.

Posted by: Astrophil May 15 2009, 10:19 AM

The Calypso pan... with reference to, I'm guessing, the Odyssey?

Odysseus (of Ithaca!) spends ten years on a Mediterranean island, 'sorrowing bitterly in the house of
the nymph Calypso, who is keeping him prisoner, and he cannot
reach his home for he has no ships nor sailors to take him over
the sea.' He gets out, but it takes a while.

http://www.gutenberg.org/dirs/etext99/dyssy10.txt

Posted by: PhilCo126 May 15 2009, 01:37 PM

I guess the last time Spirit got stuck ( Jammerbugt between sols 833 - 843 ) it sat deeper in the sand. However, let's not forget it took almost 5 weeks to get Oppy out of Purgatory Dune ( sols 446 - 484 )

Posted by: Astro0 May 15 2009, 02:12 PM

Opportunity was the one that got stuck in http://www.nasaimages.org/luna/servlet/detail/nasaNAS~4~4~19282~123959:Peering-at-Pesky--Jammerbugt-.
Actually, not even stuck. By that time they had a technique to get out from the experience learned at Purgatory.
Past events demonstrate that the Rover drivers know what their vehicles are capable of.

Posted by: ustrax May 15 2009, 03:37 PM

Did I hear someone calling?
So...what's the deal? Where do you guys want me to focus my kinetic powers?...

Posted by: SpaceListener May 15 2009, 03:54 PM

The Spirit case is even more complicated than her sister due to its inoperative right front. This causes twice obstacles: 1) No traction on both sides and 2) Yes drag in two ways but going forward causes less drag than going backward only if the RF is not able to lift a little from surface.

All at all, after long time of long dragging and if Spirit manages to reach on the other side of firmer soil, she will be back on the business.

Posted by: MerAB May 15 2009, 06:10 PM

Here a Panorma from Spirit on Sol 1904:

Posted by: Beauford May 15 2009, 08:59 PM

This is probably overly simplistic, but how about turning the wheels VERY slowly for extend periods? It has worked for me after getting my 65 Ford Galaxy 500 stuck (without a shovel) in deep snow, and in sand.

Posted by: dot.dk May 15 2009, 09:03 PM

They already do that

Posted by: nprev May 15 2009, 09:40 PM

Good time for a related amplifying base question: Are the MERs wheels constrained to drive at a constant speed? I assume that the answer is yes.

Posted by: RoverDriver May 15 2009, 11:49 PM

During each command yes, they ramp up quickly to the steady speed that is required for the motion and just prior to the end they ramp down. Just like any servo motor. But during an arc, say to the left, the left side wheels move slower than the right side, simulating a mechanical differential if you want.

Paolo

Posted by: nprev May 16 2009, 12:10 AM

Really? That's interesting. I was thinking that they were open-loop constant speed motors for sake of design simplicity, not servos.

So, Beauford's idea is possible, then? You can control wheel rotation speed with precision?

Posted by: alan May 16 2009, 08:25 PM

Some wheel movement thisol?

Comparing the image with those from sol 1899 it appears the rear bogie has move up slightly.
sol 1899: http://207.7.139.5/mars/spirit/rear_hazcam/2009-05-07/2R294958155EFFB1DNP1354L0M1.JPG
sol 1908: http://207.7.139.5/mars/spirit/rear_hazcam/2009-05-16/2R295759725EFFB1DOP1314L0M1.JPG

Reversing the rear wheels in an attempt to put more weight on the middle wheels?

Posted by: Nomadd22 May 16 2009, 08:32 PM

Does the consistency of the soil change any with temperature? Any chance things would be different in the winter now that we have nice sparkly solar panels?

Posted by: djellison May 16 2009, 08:35 PM

Simple test for the ISIL once there's a suitable buried testbed rover.... a pull test with a force meter to establish if the sort of force required to shift our stubborn girl is anywhere near the IDD's abilities.

Posted by: Tesheiner May 16 2009, 08:47 PM

Something was commanded (site/drive numbers have changed) but I can't see any movement.

Posted by: tty May 16 2009, 08:52 PM

To return to nprevs suggestion about rocking, this is the preferred way of getting yourself loose when stuck in snow here in Sweden: You gun the car for a moment, then unclutch and let it fall back. However it will move a little bit past the equilibrum position, so you catch it on the return and gun it again and so on. If you time it right the oscillation will gradually build until the car gets loose. I was taught the technique for snow, but it works just as well for desert sand and laterite clay (I've tried both). Surprisingly the technique does not seem to be generally known in other parts of the World.
I don't know if such short bursts of power are practical for MER, and the timing as I said, must be precise. Possibly it could be tried in the test-bed.

Also I would like to comment on the possible use of the IDD for pushing. It might make a difference. I remember a case when two people pushing (I was one of them) was enough to get a ten-ton truck unstuck.

Posted by: Fran Ontanaya May 16 2009, 10:18 PM

She could also wave the arm and become a http://en.wikipedia.org/wiki/Tesla%27s_oscillator.

Posted by: stevesliva May 16 2009, 10:31 PM

Too many automatic transmissions here in the states, although I was familiar with the technique with my old econobox that also didn't have power steering. It was the best possible car for detecting slippery road conditions-- both the clutch and the steering wheel let you know if you were losing traction.

I don't think the rovers have a clutch of either variety, though.

Posted by: nprev May 16 2009, 10:39 PM

I learned to drive on an old standard transmission truck in the mountains of Montana & lived in Alaska for a few years, so have had to rock out of a few slippery situations...

Problem is that doing this old-school is very dependent on real-time feedback to the driver; we don't have that luxury with the MERs. If this is tried, I'm hoping that the major effect is to precess the fore end of Spirit downslope (to the left) & let gravity help with the final extraction.

Posted by: Oersted May 17 2009, 12:00 AM

I did that rocking back-and-forth thing quite often, but I don't know what the clutch needs to be used for? I just had the van in first gear and gave it gas everytime I started on the forward motion. Basically it is like pushing a swing, you give it an extra push everytime you reach the highest point on the backswing. It is also how Robert Langdon gets out of an iffy situation involving a big book cabinet and an armed glass window in the new Angels and Demons movie

That technique really needs timing, so I think it must be very difficult to perform on Mars.

Posted by: hendric May 17 2009, 03:59 AM

Well, I don't know about timing, but it should be possible to use the IMU's accelerometers to measure any rocking and apply throttle appropriately. You push in the clutch normally on the backwards roll. Unfortunately, I don't think the wheels turn anywhere near fast enough to initiate the rocking to begin with. What's more likely is that she'll have to "swim" out of the sand by sheer brute force, using the treads as paddles to move sand from the from in front to behind the wheels. The problem is that it is a race between getting out, and the wheels sinking below the top of the hubs or high-centering on the bottom. One experiment to try is figuring out which part of the sol gives us the best traction, similar to Nomadd22's idea of waiting until winter. I'll bet that the consistency of the sand changes with different times of the day/night, as the relative humidity increases the sand/dust grains will stick together better. Plus, the area beneath Spirit is probably the coldest place on the Columbia Hills, so it'll collect any moisture around, a la freezer burn. So sitting and thinking for a bit is a good thing.

Posted by: nprev May 17 2009, 05:09 AM

Yeah, like I said, wasn't really envisioning rocking in the sense of getting out of a snowdrift. Getting the nose turned downslope via precession is about the best we can hope for IMO.

Still, though, it would be interesting (and useful!) if the MERs could execute a complex autonomous subroutine as you described, Hendric. The required response-to-feedback time is pretty short.

Posted by: RoverDriver May 17 2009, 06:29 AM

This was a short duration command on the LM wheel to diagnose the wheel stall we had on 1899. I haven't looked at the data yet, so I am not sure of the results.

Paolo

Posted by: RoverDriver May 17 2009, 06:32 AM

Unfortunately, the interval between commands is one second. That limits the response time. In addition, sensors are queried every 1/8 sec. Way too slow for any real-time control of the vehicle. Some serious coding would be needed, tested on the ground, uploaded on the vehicle and verified on Mars before we would be even attempt to use it.

Paolo

Posted by: Astro0 May 17 2009, 09:30 AM

Alan: Some wheel movement thisol?

According to their filenames, both of those images indicate that they were taken on Sol 1897. So this was preseumably some of the early moves after getting stuck. The images just came down on the later Sols.

Posted by: ngunn May 17 2009, 10:13 AM

FWIW here's how it looks to a complete outsider in these matters:

Elegant idea (using resonance as an amplifier) + proven effectiveness on Earth + outwith present capability + possibility of developing software to do it + potential benefit to other rovers, present and future + serendipitous availability of 0.4g sandbox = highly worthwhile project.

Posted by: djellison May 17 2009, 10:15 AM

The rocking technique ( I've used it as well ) involves free-wheeling back to the bottom of the little trench you dig, then throttling back up. MER can't free wheel. Essentially, it would just be driving backwards and forwards in little steps. To me- that sounds like an excellent means of digging the wheels in further, without making any progress.

Posted by: Astro0 May 17 2009, 12:11 PM

Hopefully we'll get some better visualisations soon, but I thought I'd play with a Rover model, some flour (for the soft material) and topped with some cinnamon (for contrast) to simulate for me what's going on. I created a ridge structure under the 'soils' to create a spot where loose material is stacked up against some kind of ridge, as suggested by some of the images.

I've tried to get the wheels in at roughly the right depth and haven't tried putting rocks underneath.
Just looking at it though, there's not much room between ground and WEB.
The rocks themselves though don't look that big. I guess it's more a matter of how far the RL/R and ML/R wheels have dug in.
What we really need is a look underneath Spirit.

Posted by: SpaceListener May 17 2009, 03:31 PM

I thought it too but I am still uneasy since this is a like a chess game. By taking the advantage of the left side using the gravity help but after, toward the Braun hill (south), there are small slope that Spirit must overcome that, I think it would be very tough. In order to evaluate the north evacuation way, it is necessary to study about how is the soil surface toward the north.

Posted by: RoverDriver May 17 2009, 04:28 PM

That is pretty awesome! If only that model had working rocker-bogie system the state of the wheels would have been represented with even more fidelity. If only I could use flour in the testbed but I was told it is a fire hazard. And cinnamon too! The ISIL would smell so good!

Paolo

Posted by: MerAB May 17 2009, 04:51 PM

Can you use the Microscopic Imager to see under the Rover? Or can you use maybe the robotic arm as a "mirror"? So we could say whether the Rover touches the ground.

Posted by: 333 May 17 2009, 06:03 PM

Have you considered using a mixtures of glass microballoons & sand or cement to simulate flour for the beautiful but deadly white sand traps of Mars?

Posted by: edwinkite May 17 2009, 07:11 PM

If you know the distance between the camera and the target the Lucy-Richardson method is probably optimal. Use 'deconvlucy' in MATLAB (requires Image Processing Toolbox).

- Edwin Kite

Posted by: alan May 17 2009, 11:10 PM

from one of Roverdriver's post in another thread:

Posted by: bruc May 17 2009, 11:59 PM

Talc or gypsum powder could substitute for flour, and neither burns. --Bob

Posted by: Astro0 May 18 2009, 12:46 AM

When I took the Rover model out of its 'flour-cinnamon-based' ISIL, it left behind a rather pleasing effect

EDIT: For what the 'real' ISIL will use for its soil testing...I'd say that they have that well in-hand and will come up with a perfect match based on the data they get from the Rover's IDD analysis. The nice thing about my flour-cinnamon version is that I can make a cake afterwards to celebrate the fact that Spirit has become 'unstuck'.

Posted by: nprev May 18 2009, 01:02 AM

That's so close in appearance to some of the actual HP soil exposure sites that it's downright eerie!

Posted by: RoverDriver May 18 2009, 02:01 AM

Wow. That reminds me of the testing we did in the ISIL back four years ago!


Thanks! Will look into it.

Paolo

Posted by: mhoward May 18 2009, 06:22 AM

Here's a http://mmb.unmannedspaceflight.com/MERA1902_1907Navcam.mov (4.1 MB).

Posted by: Astro0 May 18 2009, 07:13 AM

That's an awesome QTVR Michael.
The more I look at this spot, the more convinced I am that Paolo and others will get Spirit out.

Posted by: MerAB May 18 2009, 11:30 AM

Here is a false colour panorama from spirit on Sol 1906, showing a piece of the rover deck:

Posted by: bgarlick May 18 2009, 11:47 PM

IF Spirit is resting/stuck on a rock on its under side...

1) could the rover be lifted by rotating some wheels forward while rotating other wheels backwards to rotate/pinch/fold the rocker-bogie suspension and lever up the rover?

2) does the IDD have enough force to be able to lift the rover up if say the RAT was pushed down into the groud hard enough with the arm ? I could even imagine coordinating the IDD arm motion with the wheel motion to both drag the rover forward while pushing down and at the same time turning the wheels.

Posted by: ElkGroveDan May 19 2009, 12:05 AM

Folks, let's help Paolo out by reading back through this discussion before asking him the same questions over and over again. He has answered some of these several times already.

Posted by: briv1016 May 19 2009, 04:58 AM

New press release regarding Spirit:

http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20090518a.html

Posted by: alan May 19 2009, 05:41 AM

love the reflective safety vest worn by the man with the shovel, gotta make sure you aren't run over by one of the high speed rovers
http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20090518a/IMG_1623_br.jpg

Posted by: Astro0 May 19 2009, 07:03 AM

alan: love the reflective safety vest worn by the http://marsrovers.jpl.nasa.gov/gallery/pre...IMG_1623_br.jpg

Could we just send the guy with the shovel to Mars and get him to dig Spirit out

Posted by: jamescanvin May 19 2009, 07:39 AM

EDIT: I see I'm a bit late - these are already down - nice!

http://qt.exploratorium.edu/mars/opportunity/micro_imager/2009-05-19/

Posted by: djellison May 19 2009, 08:49 AM

WOW - that's better than I was expecting!!!

Posted by: Tesheiner May 19 2009, 10:24 AM

Now, if the wheels were really that big!

Edited: really, really nice pictures! I think they deserve to be included in a post, not only the links.

Posted by: Ant103 May 19 2009, 11:25 AM

OMG!

It's blurry, but that's here What a view! This is the first time we can see the middle left en right wheel. Very interesting to see that.

Posted by: Astro0 May 19 2009, 11:29 AM

OK. Don't be too critical, but here's my take on these beautiful images.
I've taken lots of liberty with them and a stack of guesses to align them and then enhanced the heck out of them.
At the very least, I think that this test using Opportunity's MI should give the MER Team confidence to do the same with Spirit.

EDIT: I agree with James (below), this is definitely a plus for Doug's 'MI MER Panorama' concept.

Posted by: jamescanvin May 19 2009, 11:46 AM

I was waiting for someone to do that - nice one Astro0 - that highly sharpened one is awesome!

That's it - I'm officially joining Doug's 'image the whole rover with the MI' campaign, it would be totally amazing.

Posted by: Ant103 May 19 2009, 11:52 AM

I do

(sad to dont't have a flexible focus on MI)

Posted by: RoverDriver May 19 2009, 12:05 PM

Unfortunately I do not know his name, but the ves is because he is one of the people who takes care of landscaping at JPL. They just grabbed a couple of them for the task. This will be a test to verify if this material would be a good simulation for the soil on Mars. We'll see...

Paolo

Posted by: RoverDriver May 19 2009, 12:15 PM

Wow, thanks Astro0. I took these to see what we could see on Spirit. The first two are taken with the IDD further from the WEB, the second set is with the IDD as close I could safely get (the turret is just under the IDD shoulder). The image quality is similar for the two positions, but in the second position we can see more detail, even the wheel cleats! In the simulation I thought I had more coverage, but it is not bad as a first attempt. Thanks for the mosaic!

Paolo

Posted by: BrianL May 19 2009, 12:31 PM

Nice pictures, but Oppy has an advantage in being at full clearance and lots of light is available underneath. With Spirit's situation, I expect it will be very dark under there. Could be hard to tell if anything is contacting the underside, unless you can position the camera to capture any gap with backlighting.

Posted by: Astro0 May 19 2009, 12:31 PM

Just to stretch the brain a little, here's a comparison of the MI images and the area under Opportunity as seen through MMB (Oppy's position as close as the program allows).
I think that there's enough detail here to pick out some of the surface features.

Amazing images Paolo (RoverDriver), well done!

Posted by: RoverDriver May 19 2009, 12:43 PM

I don't know about the lighting. We'll see. Hopefully, since Spirit MI lens is cleaner we should get more detail. It wil take some time to get the MIs from Spirit tho. We first have to run some tests with the testbed: if we have an amnesia event we need to make sure we can recover the position knowledge of the IDD. It will take a few days at least, possibly the rest of the week.

Paolo

Posted by: cbcnasa May 19 2009, 01:32 PM

Great images. What is the risk / concern of damage to the underside of Spirt?

Posted by: Stu May 19 2009, 01:34 PM

Paolo,

Can I just take a moment here to thank you for all these insights you're giving us? We all know how busy you must be right now, so it's just wonderful that you're taking the time to keep us updated with how things are going. I'm sure everyone really, really appreciates it.

More proof of how generous and cool the people at JPL are!

Posted by: marsophile May 19 2009, 03:19 PM

If the MI could look through something approximating a pinhole on the rover, that might increase the depth of field.

Posted by: SpaceListener May 19 2009, 03:29 PM

Very good testing pictures on Oppy's belly. The Doug suggestion really worked!. Now, I look forward in knowing ones from Spirit. According to the pictures photo's quality, we will be able to know better about the progress of wheels advancement in the future attempts.

I appreciate much the participation of LandRover in providing the feedback to us.

Posted by: Pertinax May 19 2009, 03:58 PM

Marsophile, please don't take this with anything but the good humor it was intended with: your comment reminds me of Guy in Galaxy Quest saying "I know! You can construct a weapon. Look around, can you form some sort of rudimentary lathe?" -- I think both MERs are woefully short on usable pinholes.


Paolo: in the MI images taken with Oppy, it looks like the MI was position a bit below the level of the WEB and pitched down several degrees? With any Spirit underbelly MIs, would the MI be positioned so the the center of the FOV would be to be even to just slightly below the WEB so as to capture the best possible profile of the terrain under Spirit? Actually, several pointing with varying pitches and MI elevation relative to the WEB might be the most useful in discerning the rough relative positions of the profile constituents. All of my comments are made with the assumption that the lighting under Spirit will be not be sufficient for anything other than silhouettes.

-- Pertinax

Posted by: marsophile May 19 2009, 04:33 PM

Anything that reduces the effective shutter size will sharpen the focus to some extent, for example, looking over the edge of a strut. Pinhole is just the extreme case.

Posted by: RoverDriver May 19 2009, 04:44 PM

The rover might be high centered on a small pile of rocks. In addition, there might be a rock in the LM wheel well.

Paolo

Posted by: RoverDriver May 19 2009, 04:49 PM

I wanted to keep the IDD turret as high as possible while still being able to image below the WEB. In this configuration we would have the turret only a few cm above the surface. I would really try to avoid scraping the turret on the ground, they might revoke my driver's license ;-)

Paolo

Posted by: Fred B May 19 2009, 04:54 PM

I'm surprised nobody has posted a deconvolution of the MI images yet, so here goes. 24 iterations of Lucy-Richardson with a synthetic PSF in Maxim DL, followed by Photoshop unsharp masking at radius 2, 500%. The panel of three is the original, the L-R, and the L-R plus unsharp. The technique is noise limited, so this would work better with better exposed, fully calibrated images and if there were some number of identical frames to average. The ringing near sharp contrast transitions is an artifact that can be reduced, but it's non-trivial to do.

Posted by: Pertinax May 19 2009, 05:09 PM

Thank you -- and please don't loose your license!

-- Pertianx

Posted by: djellison May 19 2009, 05:13 PM

That ground scraping issue was why I had a go with my cruddy low-fidelity emulation (in here http://www.unmannedspaceflight.com/index.php?showtopic=5996&pid=140354&st=20&#entry140354 ) of imaging the middle and rear wheels from the 'outside' rather than looking in. That under-belly shot is still going to be usefull and required though - to get that ground clearance data.

Posted by: MerAB May 19 2009, 06:15 PM

Here is a different (from this Sol) piece of the Calypso panorama:

Posted by: ElkGroveDan May 19 2009, 06:22 PM

That's darn impressive.

Posted by: Phil Stooke May 19 2009, 06:59 PM

Yes, we should abandon the pancam and use MI for everything!

Phil

Posted by: Oersted May 19 2009, 07:34 PM

Yes, with deconvolution and several images from slightly different locations, it should be possible to get pretty sharp images. Also, taking images of the Spirit underbelly area against the sun should give good contrasy images to work deconvolution on. Also love the idea of effectively getting a higher f-stop from shooting behind a strut, or something.

Posted by: nprev May 20 2009, 12:23 AM

I gotta second that! Extremely impressive first post, Fred!

Paolo, do we have any idea if the possible pile of rocks underneath are resting on bedrock or on a sandpile? Might make a difference if the "dig down & spin" method is attempted.

The "pile" part of the rocks is good, though; would presumably make it easier for her to slip off of them.

Posted by: RoverDriver May 20 2009, 04:08 AM

Can't say for sure, but the position of the wheels seem to indicate that this is a sandy area From the 1870 NCAM it looks like these are loose rocks, not one piece.

Paolo

Posted by: SFJCody May 20 2009, 04:49 PM

If it's possible that the mechanical properties of the soil vary significantly with temperature then maybe Spirit could try a few wheel revs in the cold martian night.

Posted by: Burmese May 20 2009, 07:52 PM

Spirit's power actuals from sol 1911: 707 Watt-hours

In some ways, being stuck while her power increases is even more frustrating...

Posted by: marsophile May 20 2009, 07:55 PM

It appears that the dust cover on the MI has a stepper motor:

http://www.esmats.eu/esmatspapers/pastpapers/pdfs/2003/dougherty.pdf

If it is possible to partially close the dust cover, this may be another way to achieve a higher f-stop. Admittedly the dust cover is partially transparent, but the difference in light intensity may be enough to sharpen the image.

Posted by: BrianL May 20 2009, 10:29 PM

Will this wind... be so mighty... as to lift Spirit out of the... diiiirt?

Posted by: RoverDriver May 20 2009, 10:55 PM

I will inquire about it. Yes we can command the dust cover to move only partially.



After 1900+ sols, we can all assume that the dust cover is completely opaque ;-)

Paolo

Posted by: dot.dk May 21 2009, 02:10 AM

Movement tosol?

Posted by: Pertinax May 21 2009, 02:18 AM

To keep my Galaxy Quest theme going -- "Digitize me Fred! Digitize me!"

I have to give it you you, I thought over the rover body and could think of nothing that would work where it would be useful, but the dust cover never crossed my mind -- to be honest I had forgotten about it.

Great thinking -- even if it can't be done, it was a good thought.


-- Pertinax

Posted by: RoverDriver May 21 2009, 05:16 AM

Over in one of the Opportunity threads there was a question on the status of the Sandbox testing. Unfortunately there is no testing going on yet. One of the disk arrays on a server that is used by the testbed has died. Restoration of the server is in progress, but I do not have an ETA yet.

One things MER has taught me is patience. I think I have to go back to my notebook and read that page again. Somehow in my head the words "grass" and "grow" get intermingled with "paint" and "dry". =:-O

Paolo

Posted by: nprev May 21 2009, 05:39 AM

Paolo, I advise you to begin drinking heavily. (Of course, that's my advice for everybody...)

A server crash at this time, huh? The perversity of the Universe never ceases to amaze. You're right, though: patience is the only answer.

Posted by: Astro0 May 21 2009, 06:22 AM

Patience - thy name is technological meltdown

Posted by: ElkGroveDan May 21 2009, 03:55 PM

If you can't use the sandbox at work Paolo, there are plenty of http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=parks&sll=34.195546,-118.171864&sspn=0.026409,0.05579&gl=us&ie=UTF8&radius=1.6&rq=1&ll=34.195546,-118.171864&spn=0.026409,0.05579&z=15. Just remember to be careful to check for sand piles where cats may have visited the night before.

Posted by: RoverDriver May 21 2009, 04:27 PM

Oh, the sandbox is ready. It has been ready for a couple of days now. It is the testbed that is not operational.

Paolo

Posted by: BrianL May 21 2009, 05:22 PM

And here I thought those were two interchangeable terms for the same thing.

Posted by: Deimos May 21 2009, 05:36 PM

Hmm, you have a ~1 mm aperture stop, and are trying to stop it down from about 20 mm in front of it (14 mm inside the camera, and maybe 6 to 12 between the window and the partially closed cover edge--which pivots out from the window). That sounds like a recipe for vignetting, rather than sharpening.

Posted by: marsophile May 21 2009, 07:16 PM

I am not an expert on optics, but it seems to me that blocking part of the visual field will mean that there are fewer light rays that are convolved with the remaining part of the field in an out-of-focus image, which might sharpen the resulting image. [Just realized: the rays that are convolved are mostly from nearby features so blocking won't really help.]

Posted by: MerAB May 22 2009, 06:07 AM

Here a panorama from Spirit on Sol 1913:

Posted by: Ant103 May 22 2009, 03:53 PM

Sol 1913 panorama, with a DD toward the plains of Gusev.
http://www.astrosurf.com/merimages/spirit-2009.html#last

Posted by: Beauford May 22 2009, 05:05 PM

EDIT: For what the 'real' ISIL will use for its soil testing...I'd say that they have that well in-hand and will come up with a perfect match based on the data they get from the Rover's IDD analysis. The nice thing about my flour-cinnamon version is that I can make a cake afterwards to celebrate the fact that Spirit has become 'unstuck'.
[/quote]


Two words seem relevant here: silica gel.

Posted by: Fran Ontanaya May 22 2009, 05:32 PM

It seems that Spirit has caught a DD in stereo:

http://qt.exploratorium.edu/mars/spirit/navcam/2009-05-21/2N296188897EFFB1DPP1840L0M1.JPG
http://qt.exploratorium.edu/mars/spirit/navcam/2009-05-21/2N296188897EFFB1DPP1840R0M1.JPG

Posted by: SpaceListener May 22 2009, 07:15 PM

I am putting a copy picture and draw with a yellow line to circle the suspected pond of basalt-silica surface. I selected the draw yellow line because the altered surface basalt-silica is inside of a small pond where the water chemical reaction might have happened. I might be wrong!

Posted by: briv1016 May 23 2009, 02:02 AM

New update:

http://marsrovers.jpl.nasa.gov/mission/status_spiritAll.html#sol1907

716 watt-hours!!!

Posted by: alan May 23 2009, 03:26 AM

The missing images from sol 1888 have finally been downloaded

Posted by: tanjent May 23 2009, 11:54 AM

As I look at these pictures, I really have to give credit to the mission planners who obviously were afraid to come this route. To my eye it looks completely innocuous. If we had seen terrain like this up on Husband Hill I wouldn't have given it a second thought. And yet, obviously, the team spent a couple of months trying to go around HP the other way. When Opportunity gets into difficulty it is always while traversing obvious sand traps, but here the "cinnamon" layer looks quite safe. The presence of the slippery flour/silica material underneath must really test a rover driver's intuition.

With the passage of enough time I hope the newly-disrupted material around the wheels will consolidate itself and allow just enough traction to push away from the high-center spot. It seems impossible to high-center the vehicle by more than a hair's breadth because as soon as effective traction is lost it becomes difficult to make the situation worse as well as better. Given enough time the wind may come to our rescue once again as stray sand grains consolidate around the wheels - I just wish I knew whether it would take a few weeks or a few million years.

Posted by: SFJCody May 23 2009, 12:29 PM

Looks like Richard Hendricks's driving at night idea is the kind of thing the MER team are considering (according to the recent npr podcast). I missed his post when skimming through the thread on wednesday which is why I posted the same idea on a previous page.

Posted by: Ant103 May 23 2009, 12:44 PM

My version of Sol 1888 color pan.
http://www.astrosurf.com/merimages/spirit-2009.html#last

Posted by: fredk May 24 2009, 12:02 AM

Yeah. Quite a nice sight.

Posted by: HughFromAlice May 24 2009, 02:27 AM

My thoughts entirely! I've looked and relooked at the photos of where Spirit is bogged quite a few times and - to me - it looks essentially no different from the harder ground around it. It's nobody's fault Spirit got bogged.

Posted by: Burmese May 24 2009, 01:00 PM

With Spirit snuggled down so close to the ground right now and with the web so close to the soil(or possibly touching), and power rising, is there any concern that Spirits' thermal danger thresholds might get reached sooner than under normal circumstances? (thinks back to the laptop he once burned up by leaving it on the carpet).

Posted by: alan May 25 2009, 03:20 AM

The left middle wheel moves

http://qt.exploratorium.edu/mars/spirit/pancam/2009-05-24/2P296461938EFFB1DPP2146R2M1.JPG
http://qt.exploratorium.edu/mars/spirit/pancam/2009-05-24/2P296462564EFFB1DQP2146R2M1.JPG

Posted by: nprev May 25 2009, 03:27 AM

Sharp-eyed observation, Alan!

I wonder if this was one of those wheel motor current tests; looks like it rotated just a couple of degrees at most.

Posted by: RoverDriver May 25 2009, 06:38 AM

No, the rotor resistance tests are done so that the motor does not move so we do not have to keep into account the back EMF. These tests were done a few sols ago. This was a 4 degrees turn. The interesting thing to note is that the LM wheel seems to move down, possibly indicating that the LM was trying to overcome a step. Since none of the other wheels were providing (much) traction it is possible that the LM stalled because it was supporting all the weight of the vehicle.

OK, I know I am speculating, but one can always dream!

Paolo

Posted by: jamescanvin May 25 2009, 10:23 AM

Nice ones Alan & Ant, however I think adding the images from 1886 adds a certain something

http://www.nivnac.co.uk/mer/index.php/a1888

James

Posted by: Phil Stooke May 25 2009, 11:25 AM

Fantastic, James - but that's 'Braun' !

Phil

Posted by: jamescanvin May 25 2009, 12:35 PM

Oops. Thanks Phil. Getting my Mars and F1 brains mixed up a bit...

Posted by: Phil Stooke May 25 2009, 12:39 PM

You're lucky to have two brains! I'm making do with half of one over here.

Phil

Posted by: ugordan May 25 2009, 12:46 PM

I'll second that, superb work, James!

Posted by: marsophile May 25 2009, 07:40 PM

Also suggested here:

http://www.unmannedspaceflight.com/index.php?showtopic=5999&view=findpost&p=140329

Posted by: SFJCody May 25 2009, 08:01 PM

Arrgh, don't know how I missed that! Sorry!

Posted by: alan May 26 2009, 02:29 PM

A suggestion: try sending power to the right front wheel, see if anything happens.

Posted by: Pavel May 26 2009, 03:02 PM

Can it be a broken up meteorite in the bottom right corner?

Posted by: djellison May 26 2009, 06:53 PM

They don't really look like the ones we've seen before.

Posted by: RoverDriver May 26 2009, 09:02 PM

Believe it or not, that is actully already on the list of things to try, but not at the top. Since the motor controllers are shared between various devices, trying to send power down a line which might be shorted could cause damage to other components of the vehicle.

In addition, and this might be stating the obvious, one advantage of not turning the RF wheel is that it won't sink! And in the current predicament it is quite helpful.

Paolo

Posted by: Phil Stooke May 26 2009, 09:24 PM

The "broken up meteorite" fragments are more likely bits of the coarse-grained layer at the base of the Home Plate layered unit. It was seen when we first got to HP, and it's here too , just above the rover.

Phil

Posted by: Ant103 May 27 2009, 12:09 PM

Yes, it adds James, excellent picture .

I have take the time to add the certain something
http://www.astrosurf.com/merimages/spirit-2009.html#last

Posted by: Burmese May 28 2009, 01:51 AM

Power up over 800 w/h now.....any clue if these are straight-line winds or direct hits by dust devils or what?

Posted by: fredk May 28 2009, 03:41 AM

Fantastic news! http://twitter.com/marsroverdriver/status/1941788866

I think the thinking is that these are usually just strong winds. But Squyres has said that the timing of at least one cleaning event suggested something more localized, like a dust devil.

Posted by: Astro0 May 28 2009, 03:53 AM

I like the suggestion of Julian (age 7) for getting Spirit http://twitpic.com/63flv.
Remember, before you laugh, many here have suggested the same thing.

Posted by: nprev May 28 2009, 03:56 AM

That's about ten light-years beyond cute.

Smart kid; a definite future UMSFer!

Posted by: RoverDriver May 28 2009, 04:00 AM

Laugh? I want to send him a present! Do you know who was the original poster of this picture?

Paolo

Posted by: Mixer May 28 2009, 04:10 AM

Paulo, I hope you do find him, I can only imagine what a thrill it would be for him!

Posted by: RoverDriver May 28 2009, 05:46 AM

Got his whereabouts. Scott Maxwell and I will send him a present.

Paolo

Posted by: jmjawors May 28 2009, 06:07 AM

That kid's practically ready to join you guys in mission operations. What are you sending him, Paolo?

Posted by: djellison May 28 2009, 07:46 AM

18 tonnes of KSC-1 mars simulant, and the mobility test bed rover.

Posted by: Mixer May 28 2009, 09:32 AM

Cackle!

Posted by: paxdan May 28 2009, 10:44 AM

I think scooterlord has some serious competition in the MER rendering department.

Posted by: nprev May 28 2009, 12:04 PM

Good on you both, Paolo & Scott; that's the definitive way to encourage the next generation of explorers!

Posted by: RoverDriver May 28 2009, 12:55 PM

That teaches me something: never read UMSF with a hot coffee mug on my hand.

Paolo

Posted by: Juramike May 28 2009, 01:42 PM

Might I suggest: http://homedecor.cafepress.com/item/space-design-tile-coaster/47765791

Posted by: MahFL May 28 2009, 01:48 PM

800 whr ? what was the whr at the start ?

Posted by: Poolio May 28 2009, 02:54 PM

Scott Maxwell indicates http://twitter.com/marsroverdriver/status/1860972063 that it was 850-900 whr.

Posted by: djellison May 28 2009, 03:00 PM

This will probably be the second time that Spirit has more power than the day she landed.Time to reopen the Gusev Crater Observatory and burn the midnight Whrs

Posted by: ElkGroveDan May 28 2009, 04:18 PM

With that much power it's time to spin the wheels so fast that the soil heats up and the grains melt and fuse. Then we let it cool down and drive out over the now solid surface.

Posted by: ustrax May 28 2009, 07:33 PM

That shouldn't be hard, Julian's dad works for NASA...it must be something in the genes...

Posted by: climber May 28 2009, 08:42 PM

I'm surprised Doug didn't make any comments on this
Even the boss is trying to drive you mad
PS: for newcomers it'll be a too loooong story to explain...

Posted by: nprev May 29 2009, 01:10 AM

Great idea, as long as we're sitting here! A couple of evening Phobos/Deimos transit movies would certainly be interesting.

Posted by: CosmicRocker May 29 2009, 07:09 AM

It was interesting to listen to SS in the recently posted NPR Science Friday interview. Along with all of you, I have been looking at the white material being churned up by some of Spirit's wheels, and wondering what it might be. There have been a few comments here referring to the white material as silica, but I couldn't find any references to support that conclusion.

As I recall, Spirit drove up and down Silica Valley, churning up a lot of white stuff, but not getting significantly bogged down. Long ago, she was almost stuck at or near Tyrone, where the white material was identified as ferric sulfate. There was another bright bog after leaving WH3, in the attempts to climb onto Home Plate or leave that area. I don't know if that bright material was identified.

In the SF interview, Steve indicated that this most recent bright stuff is ferric sulfate.

Posted by: Beauford May 29 2009, 08:30 AM

Ferric sulfate can be quite hygroscopic. ...any waters of hydration on this stuff?

Posted by: ElkGroveDan May 29 2009, 01:17 PM

I don't know how long the exposures can be, but going back to my teen years one of my favorite observing pastimes was taking long star trails to look for satellites slashing across the image. This was long before the Internet and easily available tracking data so I was left to wonder what it was that tumbled past creating dotted or dashed lines on my negatives. The processed photos were always great conversation starters In Mars' sky we know that there are several long lost orbiters. It would be a great challenge to attempt to rediscover one of them.

Posted by: Old Coder May 29 2009, 01:45 PM

Long time reader but first question. Is it possible that the back wheels on Spirit can turn forward while the front wheels are turning backward? This could use Spirit as its own resistive force rather than the dirt. If this is possible then would that action possibly raise the center of Spirit some small distance?

Posted by: fredk May 29 2009, 02:20 PM

There are several juicy tidbits in the http://marsrovers.jpl.nasa.gov/mission/status_spiritAll.html#sol1913

But the best bit is we get to find out how much more than 800 Whrs we're at now:

843!

Posted by: Deimos May 29 2009, 04:43 PM

See http://marswatch.astro.cornell.edu/pancam_instrument/projects_2.html. One of the cool things for people who are familiar with star trail images on Earth is simply that they are different. The south circumpolar trails are different; Polaris has significant trailing. Even Orion is subtly "wrong". I need to get back to the data and make nice versions of more of the data ...

Exposures can be up to about 5 and a half minutes. We didn't always use the maximum due to the density of cosmic rays in long exposures. But we have taken many star trail images as part of meteor and spacecraft searches. We briefly thought a long streak seen early was VO2--it was in a position somewhat consistent with the VO2 final orbit. After a detailed look at the orbit dynamics, we found that (a) it could not be verified as VO2 and ( a search guided by what we knew vs. didn't know would have a vanishingly small chance of catching one of the orbiters. And that was before considering they would be invisible except during "flare" type events, which we could not predict. Sadly, a test with ODY under the best viewing conditions we could manage proved the difficulty to our satisfaction.

Posted by: fredk May 29 2009, 05:18 PM

I don't remember other white stuff we've dug up having such a granular appearance as the latest dig. Have a look at this pancam view, eg:
http://marsrovers.jpl.nasa.gov/gallery/all/2/p/1910/2P295930603EFFB1DOP2283L7M1.JPG

Posted by: HughFromAlice May 29 2009, 09:58 PM

I would never have believed that Spirit would have approached anything even slightly near the 800 mark again! Just shows how wrong you can be! Gives us interesting information about the properties of that ubiquitous Martian dust.

Posted by: CosmicRocker May 30 2009, 06:32 AM

Yep...She's all powered up, but with no place to go. I hate that.

That's a good observation, fredk. As far as I know, we haven't seen that before. The granular bright stuff is different from that which we have seen at other sites. However, many of the recent images display abundant, powdery soil, as well.

I'm a bit frightened by this recent trap. Thank goodness this rover is being commanded by such an amazing team. They'll find the way out, if there is one.

Posted by: Tesheiner May 30 2009, 07:08 AM

That's tomorrowsol.

01922::p2906::02::1::0::0::1::0::2::mi_cover_open_minloss2_LUT3_crit
01922::p2906::02::1::0::0::1::0::2::mi_cover_open_minloss2_LUT3_crit
...
01922::p2976::00::1::0::0::1::0::2::mi_open_minloss2_LUT3_medium

Posted by: RoverDriver May 30 2009, 08:30 AM

Yep! This will be done in two stages. The first one will be done with the IDD further out than the position used on Opportunity. We will image the terrain just under the IDD shoulder. If the area is clear (as it should) we will take a closer look on Monday.

Paolo

Posted by: ElkGroveDan May 30 2009, 05:10 PM

Paolo when the images come down please let us know who the first person on the team is that says "Well there's yer' problem..."

Posted by: alan May 31 2009, 01:49 AM

microimages are down
http://207.7.139.5/mars/spirit/micro_imager/2009-05-30/

Posted by: Astro0 May 31 2009, 02:12 AM

Thanks for the heads-up Alan.

A real quick look underneath.

Working on better version.

EDIT: Ridiculously deconvoluted and sharpened version

Posted by: fredk May 31 2009, 02:29 AM

You scooped me by a minute, Astro0, which is fine since your mosaic is a lot better than mine!

Can someone identify the rear wheels? I'm not sure if that's the RR wheel or a high rock just left of centre and near the top of the mosaic. Also there are some rocks around the LM wheel that maybe are the cause of the stall problem?

Posted by: alan May 31 2009, 03:31 AM

The rock visible on the left in Astro0's stitch is visible between the wheels in this image

http://marsrovers.jpl.nasa.gov/gallery/all/2/f/1891/2F294253614EFFB1C6P1212R0M1.JPG

Posted by: Astro0 May 31 2009, 04:52 AM

Two updated, larger and much better versions of Spirit's MIs.

Raw image stitch, blended.

Deconvoluted and sharpened version.


RoverDriver noted that there'd be another set of MIs soon, a little closer than these.
Should improve the focus a bit.

Posted by: RoverDriver May 31 2009, 04:57 AM

Thank you Astro0 for the beautiful panorama. The rock on the left is visible from the FHAZ taken on Sol 1899, it is close to the IDD shoulder. This panorama was taken to verify that there are no obstructions under the IDD shoulder. Hopefully the next set of MIs will tell us more about the state of the wheels. In this panorama you can only see the RR wheel which is just to the right of the RM and just above the above mentioned rock. The RL wheel is not visible from this IDD position but will be from the next position. I'm not so sure what to make of the sharp spike in the middle, not sure if it is a rock, if it is touching the WEB or not.

Paolo

Posted by: RoverDriver May 31 2009, 05:05 AM

That is true, and therefore the rock with sharp edges next to it might be the pointy rock we see in the panorama. Shoot!

Paolo

Posted by: nprev May 31 2009, 05:48 AM

Major compliments to Astro0 for his brilliant, rapid mosaics!!!

Man. I dunno; shooting from the hip here, going forward (towards the POV) doesn't seem very practical anymore. Maybe turning the front wheels left, keeping the remaining good rear wheel straight, and "gunning" her in reverse might work.

Posted by: Astro0 May 31 2009, 06:20 AM

Just noticed something pretty cool in the MIs.
One of the "other" JPL logos on the MERs which we haven't seen in quite some time.

Posted by: alan May 31 2009, 06:38 AM

I'm not sure we referring to the same rock, illustration added for clarification.



The 1891 and 1897 forward hazcam images have been inverted and brightened.

original images:
http://marsrovers.jpl.nasa.gov/gallery/all/2/f/1891/2F294253614EFFB1C6P1212R0M1.JPG
http://marsrovers.jpl.nasa.gov/gallery/all/2/f/1897/2F294780294EFFB1CUP1214R0M1.JPG


I don't know where the rock on the left was originally, it looks to me like it may have been flipped. Perhaps it was in the disturbed area on the right in the 1891 image. (disturbed area would be on the left in the original image)

Posted by: Astro0 May 31 2009, 09:28 AM

Here are some comparison shots of the spot where Spirit is located.

Posted by: SpaceListener May 31 2009, 10:21 PM

Good to be able to view the previous pictures. Congrats to Astro0.

In order to know exactly the aspects of the picture. First, Spirit was traveling backward toward South (Braun Von), its IDD is on the North side. Hence, the picture was taken from North to South. The picture, I can see two rear wheels (RL and RR), both are around 70% buried. The right side of picture(RL) seems to be more obstructed, probably by a small spheric stone. The left side (RR), close to a cut stone, has higher position than the right side.

The picture, I am not able to see the middle wheels. Hope for another MI to have a better idea of the situation.

Posted by: Astro0 May 31 2009, 10:42 PM

You can see both middle wheels in this first MI image.
As RoverDriver pointed out, it's the rear wheels that are not clear/visible.
A small part of the rear-right wheel is visible in deep shadow (above the rock on the left).

More images soon we hope.

EDIT: Quick mosaic of today's soil images.

Posted by: ElkGroveDan Jun 1 2009, 04:18 AM

Let me guess a bunch, of luckless college interns are going to be tasked with manually taking an inventory of grain sizes so the test bed team can recreate a terrestrial analog to this particle mixture?

Posted by: RoverDriver Jun 1 2009, 05:20 AM

I believe that what you are referring to the rear wheels are in fact the middle wheels. The right left is behind the left middle (on the right side on the mosaic).

Paolo

Posted by: RoverDriver Jun 1 2009, 05:22 AM

How do you know? ;-) The shovels are ready! Paolo

Posted by: fredk Jun 1 2009, 03:06 PM

Getting away from the mobility situation for a moment, there was a stunning DD sequence on sol 1919:
http://marsrovers.jpl.nasa.gov/gallery/all/2/p/1919/2P296729818EFFB1DQP2288L2M1.JPG
http://marsrovers.jpl.nasa.gov/gallery/all/2/p/1919/2P296729902EFFB1DQP2288L5M1.JPG
http://marsrovers.jpl.nasa.gov/gallery/all/2/p/1919/2P296729994EFFB1DQP2288L7M2.JPG
It shows a pair of what must be gargantuan devils, since they appear to be past the horizon - I can't see any bright parts in front of the ground, just the dark silhouettes against the sky.

Posted by: djellison Jun 1 2009, 03:54 PM

I think with some stretching they will be there. Something that large over the horizon would have to be several KM's across.

Posted by: fredk Jun 1 2009, 06:52 PM

I've stretched and stretched and squinted and can't see any hint of devils in the foreground.

But I'd say these devils are not much more than a few hundred metres across. We're something like 20 metres above the plains (see http://marsrovers.jpl.nasa.gov/mission/tm-spirit/spirit-sol711.html). On Mars that means the horizon should be around 11 or 12 km away (assuming level plains). If you look at views of Grissom Hill and the big crater in behind it http://marsrovers.jpl.nasa.gov/gallery/all/2/p/1919/2P296728641EFFB1DQP2288L7M1.JPG, the horizon looks closer in distance to Grissom, which is maybe 8 km away. At that distance the largest of these devils (just under 2 degrees across) would be around 270 metres across, which is comparable to other large devils we've seen.

Of course the devils could be larger if they are farther. But they don't need to be kms across.

Posted by: ilbasso Jun 1 2009, 09:43 PM

Hmm, on my computer screen I can clearly see them extended into the foreground.

Posted by: mhoward Jun 2 2009, 12:30 AM

You didn't include this one, which was taken just a few minutes later pointing just to the right: http://nasa.exploratorium.edu/mars/spirit/pancam/2009-05-31/2P296730712EFFB1DQP2288L2M1.JPG. Not a dust devil there, more like a wind front. No wonder the deck is clean!

Posted by: climber Jun 2 2009, 07:28 AM

Do we have some pics of the clean deck shot recentely?

Posted by: Deimos Jun 2 2009, 05:10 PM

For fredk's set of 3 images, it would appear there are 4 DDs, 2 moving in tandem to the left (S), 1 indeterminate, and 1 moving faster. There is nothing in front of the horizon at the <1% level in the, uh, "good" images. So I'd buy them as a couple 300-m class DDs with a couple smaller ones.

Posted by: JayB Jun 2 2009, 06:29 PM

there's a small one in the latest PS update (from s1907)
http://www.planetary.org/news/2009/0531_Mars_Exploration_Rovers_Update_Spirit.html

hard to believe that's our girl ...forgot the panels were any colour but red


edit: lots of wind in the latest batch of NavCams

ie: http://qt.exploratorium.edu/mars/spirit/navcam/2009-06-02/2N295751630ESFB1DNP1561L0M1.JPG
http://qt.exploratorium.edu/mars/spirit/navcam/2009-06-02/2N296733409ESFB1DQP1561L0M1.JPG

Q: are all of those 256x1024 images "DD watchers"

Posted by: JayB Jun 2 2009, 09:38 PM

here's my attempt at cleaning up http://qt.exploratorium.edu/mars/spirit/micro_imager/2009-06-01/2M296987279EFFB1DQP2906M2M2.JPG


Larger rez image here (but best viewed at 30-50% zoom)
http://sidfishes.wordpress.com/?attachment_id=93

Posted by: Shaka Jun 2 2009, 11:03 PM

Good sequence for animation here. Is someone doing it?

Posted by: Astro0 Jun 3 2009, 12:04 AM

This is a quick version of part of the sequence.
Needs lots of work and I've squeezed it up for 16:9 to show the scene.
Stretches the view a bit (but that happens on UMSF! )
 DD_palooza.wmv ( 1.9MB ) : 1213

Posted by: Deimos Jun 3 2009, 12:44 AM

The P1561s are all fast dust devil movies (p1560 are "regular" movies, but haven't been used much lately, and WATCH has been used little if at all recently). We deleted a batch of the movies that have no dust devils a bit ago, so there was some selection bias to having dust devils, although the most recent ones hadn't been vetted. These go back as far as 1888. Spirit's quite deep into flash to be transmitting those. BTW, last I saw of the deck, the body and wing panels were pretty clean but the rear panel was quite dirty. But there've been more events since the pan.