Southward from San Antonio to the Next Waypoint Options

[eoincampbell]

Should we then, expect a cleaning event on the brae sometime soon?
Is the long trek actually possible without one?

[fredk]

It's worth keeping in mind that the upcoming drop down to Endeavour has a slope of only a percent or so. Meridiani is very flat. I'd be surprized if that gave much venturi effect, though I'm really not sure about this. I could see local features (craters) or large scale features (Endeavour rim) affecting the winds.

[Tesheiner]

Heading south next drive according to Maxwell.

It was executed some hours ago but I would call it "aborted" or so. The net move was just 1m.

[nprev]

Whups. Haven't had that happen for awhile, right?

[Stu]

Word has it Oppy refused to move because the drive coincided with the last episode of "Wonders of the Solar System"...

[SFJCody]

Please don't be a dead wheel, please don't be a dead wheel...

[Hungry4info]

Re: SFJCody'
Ahh fudge there went my whole day. Guess I'm slacking off on the pessimism.

Unless we hear otherwise, I'm going to assume it was just a software glitch.

[Guest_Sunspot_*]

And this isnt a very interesting place to spend the rest of the mission, at least Spirit had something interesting to look at while stuck.

[PaulM]

I asked Scott Maxwell the following question on his blog:

http://marsandme.blogspot.com/

I found Opportunity's rate of progress around SOL 400 amazing. I have heard rumours that Opportunity will soon reach easy driving country again. If so then will we be at Endeavour crater sooner than we all expect?

Scott's answer was:

We will indeed reach a nice flat zone in another kilometer or so. Once we're there, the terrain will again support longer drives, and we're looking into techniques to do those safely with the current hardware.

But what's currently constraining our progress is less the terrain and more the condition of the right front wheel: we're sticking to 70m/sol as a way to keep that wheel healthy, and if in fact we need to continue to do that, it won't matter how benign the terrain is. It wouldn't do us much good to cover 200m/sol for a few weeks, only to kill that wheel.

I should add that just now our progress is further constrained by the lower energy levels we're experiencing as a result of Martian winter's onset, but that will relax after solstice.

So, for now, you should figure that the flat terrain will still have a 70m/sol speed limit. We'd like to raise that limit just as much as you would, though, and we certainly will if we can!

[Bill Harris]

the upcoming drop down to Endeavour has a slope of only a percent or so. Meridiani is very flat. I'd be surprized if that gave much venturi effect, though I'm really not sure about this

Exactly. This effect is quite small and manifests itself as very subtle changes in the ripple morphology. Erosional/depositional processes are so gentle and can take hundreds or thousands of years to affect changes.

--Bill

[Tesheiner]

> So, for now, you should figure that the flat terrain will still have a 70m/sol speed limit. We'd like to raise that limit just as much as you would, though, and we certainly will if we can!

I can see that speed limit.

[BrianL]

Please don't be a dead wheel, please don't be a dead wheel...

With Scott's talk of purgatoids lurking about, I'm wondering if we encountered some soft ripple and stopped from slippage. The last turn in place looked a bit... messy?

It would be nice to see the latest hazcams but as often seems to happen when something unusual occurs, exploratorium is late in delivering the goods. Coincidence?

[ElkGroveDan]

As I recall the wheel current issues were somewhat alleviated by reversing driving direction now and then. I wonder if they have considered a pirouette kind of driving routine for long distances. The rover would drive 40 meters or so, stop and turn 180 degrees and resume driving in the other direction. While that might be hazardous around purgatoids, out on the flat plains it might make sense.

[fredk]

As I recall the wheel current issues were somewhat alleviated by reversing driving direction now and then.

I think rest was found to be more important than reversing direction. Check out this post from Paolo.

Paolo's posts are a goldmine of information. In this one he mentions that RF currents drop substantially on bedrock. Perhaps we can expect some drop in current on flat tarmac compared with the current ripples? I'm thinking along the lines of Spirit's wheel resistance in Troy that was reduced when they did the swimming stroke motions? Of course Spirit's case was much more severe. But perhaps a reason to hope for slightly longer drives on the tarmac.

[Tesheiner]

I wonder if they have considered a pirouette kind of driving routine for long distances.

AFAIK, this kind of manouver was already executed during the long drives right after leaving Victoria. Once again, Paolo is the source.
The first 50 or 80m of a drive were covered moving backwards in "blind mode" and the remaining part moving forward in autonav.