Another dust devil: http://qt.exploratorium.edu/mars/spirit/na...CJP1561L0M1.JPG (and moving faintly across the next few images I think?)

Yep, apparently a slight change in trajectory prior to a hopeful HPI (Home Plate Insertion), I think.

Is it only me, or are these whirlwinds approaching more closely, more recently?

I don't think they're moving 'this way'. Just more of them as the season moves on, thus more chance of seeing one that is closer than before.

My thought is that Spirit should move toward a spot where a cleaning would be most likely. Can you recall instances of winds moving over Home Plate, and how many 'cleaning' events took place while there? (My memory is faulty, but I can vaguely remember only one.)

Maybe that isn't an option, but if closer to full power could be restored, I think the possibility of getting to 'the promised land' - or nearer to it - could be again looked at.

They're too random and rare to be stated as likely at X location. We're less than 25m from where we had significant cleaning a year ago. We've had them in the hills, we've had them on the slopes, we've had them on the flat.

According to the latest update, more of an unlucky encounter:

The drive on Sol 1806 covered about 30 centimeters (1 foot). The rover team had planned a longer drive, but Spirit stopped short, apparently from the right front wheel encountering the partially buried rock visible next to that wheel.

There's another attempt in today's schedule (1809).

Replaced in-line image with a link - Mod

http://marsrovers.jpl.nasa.gov/gallery/all...DHP0713L0M1.JPG

Nice shot.

Those solar panels really need a cleaning

Also in the latest update:

Maybe, to anthropomorphize our friend Spirit, she's feeling a little dizzy after being tilted at wh3 for so long and then abruptly returning to level ground.

Some fresh images on the web from sol 1809. Spirit is inching her way to the top of Home Plate.
http://qt.exploratorium.edu/mars/spirit/re...E4P1314R0M1.JPG

There's some very interesting information in the new batch of Spirit updates. In this one, it says:

It appears they tried this not long before sol 1772, according to this quote:

This must be the explanation for the dust movement on the solar panels that we talked about at the time! Looking at those images again, it does appear that the dust movement is consistent with the downslope direction.

Didn't someone on UMSF suggest they try something like this?

I suggested they lean the IDD arm on the edge of the solar array, and spin the RAT or brush. I wouldn't have expected this to work with the wheels because they are too well balanced and turn too slowly. Who knows? Wear and tear on the RAT should have thrown it out of balance by now.

Apart from "why didn't you include windshield wipers on the deck" this is probably the most common question I get asked ;-)

Paolo

I'd think that the middle wheels were contacting the ground at this time, so even though they spin slowly and are well balanced, you could get abrupt jolts to the rover, for example when a wheel cleat loses contact with a piece of rock and the wheel suddenly drops down a bit.

That's what I would have expected. Alas the accelerometers reported very little shaking even when all 5 wheels were moving.

Paolo

Who knew that we'd need to turn up the motors to 11 to shake dust off arrays

And here's the reference for that reference...

http://www.youtube.com/watch?v=d54UU-fPIsY

When the dust on the solar panels starts forming into dunes, then we'll know we're in trouble.

Well, now that you mention it, Diane...Latest NavCam

Boy howdy...A beautiful yet disturbing shot. May random chance favor her with one hell of an opportune gust...

Is that the offending "partly buried rock" over there, among all the torn-up dirt..?

Click to view attachment

Sol 1811 116x90 degree perspective projection

Looks like we are almost up. Some slipping, but almost there.
Navcam
RearHazcam

With the mad dash across HP set to begin soon (he says with hope), the question comes to mind...

Do we know there is a safe way down off HP at the south end?

I Google Marsed that issue and it looks like a nice slope down at the junction between the plate and the ridge along its southern side. That area was imaged in stereo to plan a descent, on sol 1348-50.

Phil

I could see at least a few good routes off of HP. At the southernmost part of HP, there's basically no dropoff as you exit from HP.

The first exit route is between Low and SW ridges (see Tesheiner's map). Here's the view from sol 1337; we'd go straight into the middle of this view and then turn to the right:
http://marsrovers.jpl.nasa.gov/gallery/all...FUP0716R0M1.JPG

The second is just west of the high point of SW ridge, though it's a bit hard to know what the south side of SW ridge will be like. This route would be into the left side of this frame:
http://marsrovers.jpl.nasa.gov/gallery/all...FUP0716R0M1.JPG

Finally, a twist on the previous route would be to go a bit farther west and taste the outcrop rock of "the saddle":
http://marsrovers.jpl.nasa.gov/gallery/all...JAP1907R0M1.JPG

Now there's an awkward verb.

Awkward, maybe - but I wanted to be the first person to use it.

Phil

Ouch! Getting on top of HP won't be an easy task.
Last drive moved the rover just a few cms and the LF wheel started to dig in the sand.
Click to view attachment -> Click to view attachment

Paolo--can you give us some expert insight? Spirit will have front wheels on the top in only 2 to 3 feet of driving. Do you plan to keep moving slowly ahead even with the digging in, or will some more complex maneuver be necessary?

I have to look at the entire telemetry before I can suggest a course of action but the FHAZ does not look good.

Paolo

The rover's positioning data (x, y, z) suggest it was expected to drive about 60cm but moved only 10cm. 85% slip factor.

Latest 3D view... nice depth of field in this one, I think...

http://stugallery.files.wordpress.com/2009...eb11-spirit.jpg

Would the lay of the land permit a more angled approach, much as Oppy needed to get out of Eagle crater?

Thanks Paolo. You know there are a few thousand back seat drivers here, so we really appreciate getting the thoughts of a real driver.

That's what we are trying to do. Climb cross-slope. It worked in Tartarus, not sure if it will work here. We'll see what happens next.

Paolo

I suspect the Principles of Universal Balance (I've long been a supporter of PUBs) are at play here. Oppy's incredible driving success is being balanced by Spirit's futility. If you were to hobble Oppy's progress surreptitiously so the universe does not realize what you are up to, then Spirit might be allowed to move more freely.

I think it's worth a try.

#include <std-smileys.h>

Hey, hey, hey! Who are you calling futile! When was the last time you tried to tow a caravan uphill on a 20 degrees slope , parking brake set ... with a MOPED?

Paolo

HOORAY! Only 30 WHR additional, but we'll take it! Via marsroverdriver

Hurrah! It may be only 30 additional WHrs, but the boost apparently doubles our discretionary spending allotment.

Thanks for that welcomed news.

On the other hand, today's images are not good at all. The LF wheel is still sinking...
Click to view attachment

Here's an animated gif with the pictures from the last three driving sols.
Click to view attachment

Speaking firmly entrenched in the back seat, Paolo...

What about heading for Fred's mentioned exit point by staying off HP, rounding the horn and zipping down Silica Valley? Is this route under consideration?

We are currently on the route previously used to get to Silica Valley. We cut the corner of Home Plate back in the Sol 767-774 range. That was, of course, before we had the FR failure.

http://marsrovers.jpl.nasa.gov/mission/tm-...MERA_A906_3.jpg

Yes, we are evaluating it. *my* worries with that path is that a large part of this traverse is unknown. The NE corner of HP is not fully covered by NCAM and PCAM, but mostly south of Silica Valley, west of Tyrone it is an are where we only have HiRISE coverage, no surface imaging and in order to get surface imaging we would need to drive close to the SE corner of HP. And in that case you are pretty much committed to that route. So it represent a risk.

This is my personal view.

Paolo

PS: I don't mind the back seat driving at all. It might be that most of the ideas are already under consideration, but it just takes *one* good idea from you guys to make a difference.

Heh. Can Spirit climb rocking like a lizard? That would be funny.

Nice view of Spirit's tracks around Homeplate - and yep, that wheel looks a bit chuttered up...

http://stugallery.files.wordpress.com/2009/02/feb13.jpg

On sol 1820 Spirit moved a bit back downslope:
http://qt.exploratorium.edu/mars/spirit/fo...OLP1214L0M1.JPG
http://qt.exploratorium.edu/mars/spirit/re...OLP1314R0M1.JPG
I wonder what's next...

Click to view attachment

Homeplate area through same mathematical filters I used for oppy. Green is good driving, blue is more difficult driving, and red is danger. Offcourse, which one wheel less criteria will be somewhat different for Spirit, but at least it gives the relative values. Red lines on top and bottom of image are processing artifacts.

Click to view attachment

'Dust-filter' as used for Oppy, red notes dusty/sandy area's, however not sure whether this will work out similar on the homeplate area as it does on Meridiani...

Regards,

Geert

Thanks for these, Geert. Could you summarize what signals you're plotting - FT, variance, etc? And how do you try to detect dust?

Indeed the interpretation is very different for Spirit. Recall that she drove up onto HP on sol 1306, with broken wheel, through a patch you've coloured red...

This is quite interesting indeed. The climb on HP on 1306 was on an area that was bedrock and in this plot it is colored green. I do not believe Geert took into account the slopes in this plot, just the terrain type (correct?). That is why we were able to move about Silica Valley while it is painted in red for example.

Paolo