[X] My Assistant

[BrianL]

Given that 6-wheeling days may be numbered, what is the shortest route to permanent (as in all the way to Endeavour) parking lot terrain?

[Juramike]

what is the shortest route to permanent (as in all the way to Endeavour) parking lot terrain?

Turning E immediately and weaving through the flattest (blue/aqua) terrain to the green parking lot stuff.

[eoincampbell]

Any reason to suggest why the RF wheel is the problem wheel for both MER's?

[Geert]

Turning E immediately and weaving through the flattest (blue/aqua) terrain to the green parking lot stuff.

With all due respect, Mike, but I don't believe turning east now will do us much good. It will take us away from the 'yellow brick road' bedrock patches and on sand again, and it will mean driving perpendicular to the dunes ('against the waves').

Looking at the past weeks, it seems to me that trouble started building up when oppy was crossing a patch of sand, I'm still hoping that staying on bedrock as much as possible will help to reduce the load on the gears. This means following the 'yellow brick road' as set out by Rui/Ustrax, turning a bit more to the right, and keeping Porcupine on our left hand side, then making a turn east after passing Porcupine. There are still some patches you have to pass, but that will keep us on bedrock most of the time and 'nasty' dunes can be negotiated on a southerly heading which gives the least problems.



This is my own latest terrain calculation ('dune' filter) at 1 mtr/pixel for the area south till porcupine. Blue is suspect and Red should be avoided. The best option still seems to be to keep Porcupine on our left hand side (passing close to the edge, remaining on the bedrock). Other possible option would be to continue dead south from the 1806 position, keep Porcupine on the right and zigzag between the blue patches, however that would give a longer distance on sand.



The same for the area south of porcupine, once we have passed Porcupine terrain should get better and there will be a good option to turn east as soon as she is (temporarily) out of the dunes. This is conform the route of Rui/Ustrax.



Finally the same map again, but looking towards the east-south-east from the 1806 position. Turning east now will lead us away from the bedrock with several suspect 'dusttraps' and still a lot of dunes. Eventually it will lead us indeed to better terrain, but at the cost of having to drive perpendicular to the dunes for quite some time and on sand.

Presently I suspect Oppy is heading for this (as yet unnamed) buried crater a little over 100 mtr south of the present position, I guess the final route past Porcupine (passing east or west) will become clear once she is past this crater. We will wait and keep our fingers crossed regarding the wheels...

Regards,

Geert.

[Juramike]

Dunno.

The pavement patches are starting to thin out in the "yellow brick road".

There are some potentially yukky dunes (magenta/red) in the dune field E of Porcupine. Even W of porcupine has some blue/magenta terrain.

I'm not so sure about the potential dust traps. Some of our models had predicted potential issues in the area near Sol1795, Sol1796, and Sol1797. It looks like an older infilled crater. We crusied through there with little problem.
The treads did sink in a little bit more than up in the parking lot near Endurance.

Turning E now, we would encounter terrain significantly LESS nasty than the recent cross-dune traverse of Sol1786 and Sol1791. Going ESE, within 100 m (2 driving sols), we would be in terrain less scary than Sol1691 - corresponding to the outer apron of Victoria Crater.
BUT, that cross-dune traverse across blue/aqua terrain would wiggle E for about 1 km before getting into true parking lot terrain.

From a science perspective, I'd imagine the drive E would be really, really boring. Aside from a drive by my favorite cute little 50 m crater, every day would pretty much look like the rest. ("Hey, look, more dunes.")

-Mike

[Geert]

There are some potentially yukky dunes (magenta/red) in the dune field E of Porcupine. Even W of porcupine has some blue/magenta terrain.

Agreed, I think West of Porcupine is slightly more favorable terrain but both options will mean zigzagging a bit to avoid bad spots. This might mean driving backwards until close to Porcupine, then passing that area driving forward on autonav, and turning backwards again south of Porcupine.

I'm not so sure about the potential dust traps. Some of our models had predicted potential issues in the area near Sol1795, Sol1796, and Sol1797. It looks like an older infilled crater. We crusied through there with little problem.
The treads did sink in a little bit more than up in the parking lot near Endurance.

Yes, but I think it is significant that the RF wheel gear problems started again during those days!

The forward wheels take the most stress from driving in sand, as they 'dig' the trench in which the other wheels are following. I'm afraid driving in sand is not good for the gears and that's why I'm reluctant to leave the bedrock (although you can't avoid leaving it in the end).

'Dust traps' are nasty items to spot mathematically, I didn't include my 'dust filter' maps in the earlier post as they might be misleading. It is hard to say where you have to place the 'red' marker on those maps, the 'fingerprint' method I'm using now for the terrain calculations relies heavily on historical data (collected by you, of which I'm very grateful). The software attempts to match the terrain with past history and this is how the color-designations are created on all the maps. For dunes/craters/bedrock there is sufficient data but with dusttraps we (fortunately) don't know 'how much she can take', so the maps for dust tend to be overly pessimistic and red area's can often be crossed with no problem. Still, I don't want to find out what is the exact limit for 'red'...

Turning E now, we would encounter terrain significantly LESS nasty than the recent cross-dune traverse of Sol1786 and Sol1791. Going ESE, within 100 m (2 driving sols), we would be in terrain less scary than Sol1691 - corresponding to the outer apron of Victoria Crater.
BUT, that cross-dune traverse across blue/aqua terrain would wiggle E for about 1 km before getting into true parking lot terrain.

I fully agree that she can easily 'take' the cross-dune east portion (on my above maps it shows green with only isolated blue spots), but I'm worried how much stress driving for 1 km in such terrain will be for the gears...

Well, fortunately we are only sitting in the backseat, I'm very interested what the true drivers will decide, guess we will find out soon enough..

Kind regards,

Geert.

[Nirgal]

From a science perspective, I'd imagine the drive E would be really, really boring. Aside from a drive by my favorite cute little 50 m crater, every day would pretty much look like the rest. ("Hey, look, more dunes.")

-Mike

I would rather take 200 straight "boring" driving Sols in a row, if this increased the chance to reach Endeavour and spent whatever remains from the science hardware there,
because that's where the most exciting science stuff waits, IMHO :wheel

[AndyG]

Aside from a drive by my favorite cute little 50 m crater...

Is that the one I can only refer to as "Midway"? She's plumb centre here.

Andy

[Geert]

Terrain overview map of the Porcupine region with some of the possible routes through.

Green is normal driving, blue is suspect area, red is danger.

Regards,

Geert.

[RobertEB]

Is that the one I can only refer to as "Midway"? She's plumb centre here.

Andy

That whole lower section looks interesting. Craters of all sizes and various stages of erosion.

[BrianL]

Any word on when the next drive will be? How's the wheel current? Am I too impatient?

[djellison]

Am I too impatient?

That one I CAN answer.

[Guest_Sunspot_*]

Are they still dealing with that dodgy wheel?

[Tesheiner]

Either that or a stop to do some pancam science. IMHO probably both.
No drive was planned during the whole week.

[Poolio]

Either that or a stop to do some pancam science. IMHO probably both.

There have been a number of PANCAM images of the rover's wheel tracks taken in the past few days, using all the camera's available filters. I assume these are scientific in nature. To my untrained eye, the bright material is reminiscent of the silica found by Spirit at HP. Any thoughts?

Or are the pictures diagnostic, part of the analysis of the RF wheel?