Last stops around Victoria, before the Long Trek Options

[Tesheiner]

Let's use this topic for the last stops (Cabo Frio, perhaps?) before Opportunity leave the vicinity of Victoria for good.

[Tesheiner]

This is a guess, but I'm pretty sure we'll stop at Cabo Frio before leaving. Paolo?

[RoverDriver]

This is a guess, but I'm pretty sure we'll stop at Cabo Frio before leaving. Paolo?

I hope not. Today's plan is somewhat more ambitious. I don't want to jinx it, I have a few more hours to wait. I will keep you posted.

Paolo

[mhoward]

Well that's intriguing

Seems like a long time since we've seen drive-direction mosaics like this:



Looking south, even... it brings a smile to my face.

[mhoward]

Here is a Sol 1661 QTVR (2.1MB), just because the scene is so beautiful.

[centsworth_II]

Today's plan is somewhat more ambitious.

I wonder if "Last stops around Victoria, before the Long Trek" is destined to be a very short thread.

[ngunn]

the scene is so beautiful.

It sure is - and thanks very much for making it so real for us. An emotional moment, it reminds me of our first glimpse in.

[ilbasso]

Enjoy the scenery while it lasts, kids, we're about to start driving across Kansas!

[Tesheiner]

I wonder if "Last stops around Victoria, before the Long Trek" is destined to be a very short thread.

This idea crossed my mind at the right moment I opened the thread. Then I said "no way, Cabo Frio is a mandatory stop!", but now after Paolo's comments I'm not sure of anything. Will we see one of those 100m drives today?

[nprev]

That is indeed beautiful, and thank you for the gift, MH.

Inspiring as well, and for those who don't care for poetry, my apologies in advance:

Leaving Victoria

The horizon has never been featureless
and now we must leave the layers
of the mysterious past, for our limitations stop us now
but only now
for all life is short, and we must leave.

This alien place, this new home
must be seen, must be touched as much as possible
and the distant cliffs beckon, there is no resistance
Victoria gives us up willingly, for we are strangers still

Onward, for as long as we can
Onward, through dunes and cold and penetrating frosty dust
Onward, past cobbles and meteorites
Onward, till the power is gone, and our vision grows dim...

Someday we will stand static and alone, but not forever
and never now
we go onward, and see what must be seen
we go
now

[Phil Stooke]

What is it with all these poets? Well, if they can do it so can I.


There once was a rover called Oppy,
Whose aiming once got a bit sloppy.
Things got rather gory
Inside Purgatory,
But now she is driving non-stoppy.



Philliam Shakespeare

[nprev]

...LOVE it!!!!

(BTW, Phil, still waiting on that damn mascot job to open up for your school...I've switched to even cheaper cigars!!!)

[Shaka]

4,245,000 bottles of beer on the wall...4,245,000 bottles of beer...

[RoverDriver]

This idea crossed my mind at the right moment I opened the thread. Then I said "no way, Cabo Frio is a mandatory stop!", but now after Paolo's comments I'm not sure of anything. Will we see one of those 100m drives today?

Not really. Almost 153 meters straight south. Don't be alarmed, there will be no imaging today, we'll have to wait one more day to get them. One of the tricks we will probably use during this adventure.

Paolo

[PDP8E]

there once was a rover, quite clever
who was in Victoria forever
then one day she popped out
and aligned to the south
for Squires had said...Endeavour!

[Tesheiner]

Almost 153 meters straight south.

Oh boy!
Should I change the thread's name to "Running around Victoria before the Long Trek"?

[djellison]

One of the tricks we will probably use during this adventure.

Ahhh ( going onto guess mode )

Driving limited perhaps by time rather than power - so if you forgo the imaging at the end of the drive before stopping for the PM UHF pass, you can get more drive time into the schedule.

Do this when on restricted sols and you can pre-estimate Sol N+2's drive from engineering and HiRISE - and give it a go/no go when you get the post drive imaging on Sol N+1

Just guessing

Doug

[RoverDriver]

Wow, you are so good! Your first guess is 100% correct. The second is currently incorrect. Before we move the rover there is minimum set o data we need to receive before we are allowed to drive again. Front and Rear Hazcams is one of these products. Therefore this trick can only be currently applied on weekends.

We are trying to relax the risk posture, but it will take time to understand what we can relax and still maintain the vehicle safe. This drive had one component that was relaxed which I think it will be accepted. I'm sure we will need to come up with many tricks to get to Endeavour before the juice runs out.

Paolo

[BrianL]

Paolo, given the relative safety of the current driving surface, have you considered going for a new single drive record, which I believe is currently 220 meters?

[Tesheiner]

Therefore this trick can only be currently applied on weekends.

That was my guess.

[RoverDriver]

Paolo, given the relative safety of the current driving surface, have you considered going for a new single drive record, which I believe is currently 220 meters?

I'm sure all rover drivers are thinking about it but (I hope) we are disciplined enough to think about the goal which is not beating the record but to get to Endeavour.

Paolo

[Guest_Bobby_*]

I agree with you Tescheiner. I think it would be fun going around Victoria but we do need to start
our journey South.

What areas along the West side or Southern part of Victoria might be good places to go to and
what area south of Victoria should we stop at to explore??? First targets?

[RoverDriver]

I agree with you Tescheiner. I think it would be fun going around Victoria but we do need to start
our journey South.

What areas along the West side or Southern part of Victoria might be good places to go to and
what area south of Victoria should we stop at to explore??? First targets?

We have received indicaions for a couple of spots in VC rim in the west and SW. The first stopover is about 150-200m SE of where the rover currently is. The next stopover is about 300m SE of the first stop. After these two locations, I have no indications whether there will be additional stops or is we are fre to leave VC.

Paolo

[Guest_Bobby_*]

Thanks Paolo for the information.

Since I'm not into drawing overhead shots of Victoria.

I hope one of our computer drawing guru's in here might determine
which area of Victoria is the 1rst target Paola said is 150 to 200 meters SE
of our current location and the 2nd target which is 300 meters SE of where
we are?

[Astro0]

This is like a treasure hunt or playing "Where's Opportunity?" ... head south 153m, then southeast for 150-200m and find a target southeast 300m of your first position.
OK, so without taking a massive leap across an unnamed 'bay', I guess that with a few turns we'd end up somewhere here (?)
Any location along this part of VC will produce great views (oh, and of course 'great science').
I'd especially like a view across that large slumped area. Plus the view back along VC to Duck Bay will be spectacular!
Anywhere really....Go Oppy!



Astro0

[BrianL]

Astro0, I took Paolo's comments to mean:

Go 150-200 m and stop.
Go 300 m beyond that and stop.

Paolo?

[RoverDriver]

This is like a treasure hunt or playing "Where's Opportunity?" ... head south 153m, then southeast for 150-200m and find a target southeast 300m of your first position.
OK, so without taking a massive leap across an unnamed 'bay', I guess that with a few turns we'd end up somewhere here (?)
Any location along this part of VC will produce great views (oh, and of course 'great science').
I'd especially like a view across that large slumped area. Plus the view back along VC to Duck Bay will be spectacular!
Anywhere really....Go Oppy!



Astro0

I apologize if I gave the wrong distances, I was roughly quoting from memory. On the image above, the end of your tracks are exactly at the second (and last) imaging location at VC. The first location is at the edge of the rim just above the 150 marker.

Paolo

[Astro0]

Thanks Paolo.
I thought my guess might be right.
My "inner explorer" told me that this particular cape would be a good science-stop and would be the last(?) stop on Oppy's VC journey.
Bring on the trek to Endeavour....we're with you ALL the way.

Astro0

[ElkGroveDan]

Let's say it's 200m SE and then another 300m SE, then anywhere along these two lines and yellow arcs could be the destinations.

I'd be really surprised if they would do a 150 meter drive that close to the edge of the crater. Paolo? What are the rules?

[RoverDriver]

I'd be really surprised if they would do a 150 meter drive that close to the edge of the crater. Paolo? What are the rules?

There are no rules! No cops, no "traffic patrolled by aircraft", wait a minute! We are patrolled from above! I better slow down! ;-)

Seriously, the tracks Astro0 posted are way too close to the rim. When we approach a target on a crater we align to the target by staying at a safe distance (a few 10s of meters) then dedicate one or two drives to the approach depending on how critical the position is and how close to the rim we need to be. This might mean a longer route, but quicker. And as everyone who has walked the hills of San Francisco has found, the straight line might not be the easiest, quickest, requires less energy or even possible.

Paolo

[Astro0]

Paolo - "Seriously, the tracks Astro0 posted are way too close to the rim."

Hey, I didn't say that I knew how to drive but I do know where we are going!

Astro0

[CosmicRocker]

Good hunch there, EGD.

... On the image above, the end of your tracks are exactly at the second (and last) imaging location at VC. The first location is at the edge of the rim just above the 150 marker.

hmm...That looks like a good set up to do one more long baseline stereo pair. If so, it would be nice if it could be done in color.

I'd also suspect that if the second stop on the rim is the last, that afterward, the route would go pretty much directly south from there.

[RoverDriver]

Good hunch there, EGD.

hmm...That looks like a good set up to do one more long baseline stereo pair. If so, it would be nice if it could be done in color.

I'd also suspect that if the second stop on the rim is the last, that afterward, the route would go pretty much directly south from there.

I haven't heard any mention of superres or WBS on the first target.

Paolo

[CosmicRocker]

I haven't heard any mention of superres or WBS on the first target.

Yes. But even if it wasn't planned, we will do it, if we can. The database might announce the intentions. I wasn't expecting superres unless something exceptional was noticed.

We only need overlapping images from those two locations, and it would seem neglectful to not collect more long distance 3D from the SW corner of the crater before Opportunity leaves. But, what do I know.

[Tesheiner]

Driving limited perhaps by time rather than power - so if you forgo the imaging at the end of the drive before stopping for the PM UHF pass, you can get more drive time into the schedule.

More info on this loooong drive: it started around 12:45 and it took 'til 16:30 to cover those 150m with some stops in the way to confirm "all is well". This one hasn't the record in terms of distance, but perhaps it has the record in terms of driving time.

[BrianL]

(I hope) we are disciplined enough to think about the goal which is not beating the record but to get to Endeavour.

Interesting comment. Perhaps I'm reading too much into it, but it sounds like you are saying that very long drives are not good for the long term mobility of the rover.

[RoverDriver]

Interesting comment. Perhaps I'm reading too much into it, but it sounds like you are saying that very long drives are not good for the long term mobility of the rover.

No, I really mean that while trying to do long drives we still maintain the rover safe. The goal is getting there, not die trying to.

Paolo

[djellison]

Interesting comment. Perhaps I'm reading too much into it, but it sounds like ...

"How far can we go?" not "Can we go more than 220m?"

Doug

[Fran Ontanaya]

Please, excuse my ignorance. Would Oppy need to do a cool down stop if it drove for too long?

(I know, it isn't a F1, but the martian air isn't very conductive either.)

[Tesheiner]

Dunno.
But what I really know is that our fellow rover (or the driver behind ) is a little bit "drunk".
Check the wheel marks: http://qt.exploratorium.edu/mars/opportuni...23P1312R0M1.JPG

I know, I know! That's deliberately made to ease the work for the autonav (or whatever it's called).

[djellison]

Drunken sailor walk

I don't think the rover motors would overheat. With 900+Whrs during high summer, the WEB may get to an overheating situation ( as happened at the summit of Husband Hill briefly ) - but the rover motors are so exposed that I find it hard to believe they could get warm to the point of being worrying.

Doug

[climber]

Drunken sailor walk
Doug

Realy? I thought it was more eratic. Well, last such drive was over 1 year ago and I don't remember very well. I didn't though we'll ever have to use it for real!
Anyway I guess she'll use lot of this technique for quite a while. I intentionnaly say "she" because I guess we can call this "self navigation" as opposed to "ordered navigation".

[djellison]

I don't think this was an example of the drunken sailor walk - but that's what they called it when the rover stopped quite regularly to give autonav / visidom something to see.

Doug

[Guest_Bobby_*]

Are we on a day on/day off schedule for driving now or can we drive everyday?

[djellison]

I would say at the moment we're on restricted sols.

Doug

[Phil Stooke]

New maps at JPL, including some new placenames on Victoria's rim:

http://marsrovers.jpl.nasa.gov/mission/traverse_maps.html

Phil

[ustrax]

Got some words from SS, on the stops Paolo made reference to, the reason and how much time will Oppy take there?:

"The objective there will be the same as the objective was at our many stops along the northern rim... to image stratigraphy on the opposing cliff faces.

It's hard to predict exactly how long they'll take, but we'll try to get them wrapped up as quickly as possible."

And what about aditional stopovers? Will there be any or are we clear to hit the road after these two?

"You never know... depends on what we find. We're exploring new territory now, and whenever we see something that merits a stop, we'll stop. But we intend to hit the road as soon and as fast as we can."

"hit the road as soon and as fast as we can"
I like the sound of that...

[Guest_Bobby_*]

May October show us Journeys like this daily

Attached thumbnail(s)

 

[tim53]

New maps at JPL, including some new placenames on Victoria's rim:

http://marsrovers.jpl.nasa.gov/mission/traverse_maps.html

Phil

Hi Phil:

Now that we're under way again, and I've got a groovy new tool, I've gone back and corrected all the locations back to the lander. Based on the quality of the overhead projected Navcam pans (at a resolution of 1cm/pixel) and the resolution of the HiRISE mosaic I'm using (25cm/pixel), I can just about "guarantee" the locations are accurate to about a half meter. Next step will be registering the HiRISE mosaic to the Mars control net.

-Tim.
PS: For your perusal

[Phil Stooke]

That's great, Tim - both the new map and the news that the locations are fixed all the way back to the lander.

Will that full location data set end up in PDS at some point?

Phil

[ElkGroveDan]

For your perusal

Well that one sure is a keeper.

[RoverDriver]

Sol 1666 seems to be one more for the books: ~130m The Penultimate RHAZ is really cool.

[CosmicRocker]

Well that one sure is a keeper.

Sweet... ...saved to the hard drive for future reference...

I looked everywhere for Paolo's teaser sol 1666 Penultimate RHAZ image. I couldn't even find the thumbnail at this time.

Edited: I just remembered that we only find thumbnails of pancams at the pancam tracking database interface.

[CosmicRocker]

I like the new traverse maps, in concept, but it seems we might still find better ones here. I don't understand why so much of the background HiRise resolution is obscured. Was something lost in translation to jpg?

[Tman]

If you refer to the third map, only the middle one is in full resolution maybe fading a bit due to colorizing or less sharpening.

Super this new concept!

[Stu]

(Stu leans out of car window...)

Hey, guys! Look over there!!



( EDIT: wider angle view here )

[climber]

(Stu leans out of car window...)
Hey, guys! Look over there!!
( EDIT: wider angle view here )

Stu, did I ever told you that you're at 3D's what Eduardo is at Oppy's route map?
Thanks so much, this view is very very inspiring and I guess we've gona miss it pretty soon or ???
But anyway, when one get a 22' screen, the original post is much better than a wider angle that take only half of the screen

[Tesheiner]

Sol 1666 seems to be one more for the books: ~130m The Penultimate RHAZ is really cool.

Here it is, with a bit of gamma correction because the original is too dark, at least the JPEG.

[ustrax]

The middle of a working week, a beautiful day outside,
and here I am, stranded at home, after catching a cold on a funeral...

And then Stu takes me to Mars and puts me in the rim of a crater, with this breathtaking scenario and with little cobbles around for me to kick...
This is what friends are for...
Brilliant!

[Tesheiner]

Q & D polar projection of the navcam mosaic taken on sol 1664.
We can see Cape Verde almost to the N (top) and "Cape Pillar" to the ENE.

[MahFL]

Did Oppy just drive 283 meters in two drives ?

[Tesheiner]

Give or take a few meters, depending on if we are talking about net distance or "odometer", but the answer is basically YES!!!!


Now, wait a minute!

As of sol 1653 (Sept. 17, 2008), Opportunity's total odometry was 11,796.22 meters (7.33 miles)

That means we have already crossed the 12km mark!!!

[ustrax]

Did Oppy just drive 283 meters in two drives ?

Only 11.717 to go!

Cool to know that if Oppy kept this average (141.5) everysol she would arrive Endeavour in 82 sols!
I'm deliberately not taking into account that we're not driving in a straight path towards the crater...but, optimist as I am I see the 2 year drive as a very conservative timeline...

[RoverDriver]

I tried to correct the penultimate rhaz. Here it is.

Paolo

Attached thumbnail(s)

 

[djellison]

if Oppy kept this average (141.5) everysol

It took 5 sols to cover that distance. Not two. Two drives - but five sols.

And this is just about the best driving terrain we'll ever have, and we wont have it for long ( at this pace ).

A fast couple of months, then it's going to be painfull.

[Toma B]

It took 5 sols to cover that distance. Not two. Two drives - but five sols.

I'm not moaning but:
Do you know why it took 5 days?
Restricted sols can explain 3 days instead of 2 ,and isn't MRO started relaying data from MERs?
Can there be a "restricted sol" with 2 orbiters relaying data?
Anyway.....these last 2 drives were just great.

[tim53]

I like the new traverse maps, in concept, but it seems we might still find better ones here. I don't understand why so much of the background HiRise resolution is obscured. Was something lost in translation to jpg?

The file with "25cm" in the filename is at the full resolution of the HiRISE mosaic. The Navcam overhead is rendered at 1cm/pixel for the planning tool, but unless folks can open something like Jpeg 2000 format, putting a 1cm/pixel zoom of the map on the rover website would be difficult. Easy to produce, though.

-Tim.

[tim53]

I averaged the distance we covered between the heatshield and Purgatory, and came up with something like 30m/day, which includes weekends and sols we stayed for science purposes. Between Purgatory and Beagle Crater, our average slowed to less than 15m/day.

But things are different now. We have this awesome HiRISE coverage (which, in a few days will be complete all the way past Endeavor's west rim) to help us plan our route through, or around the "purgatoids" south of Victoria. After about 3-5km of slogging through fields of purgatoids, the ripples drop off in size dramatically (and we go down a broad 60 meter slope), and so far as I can tell at this point, the surface should look more like the plains around Endurance than the ripple fields we've been dealing with around the Victoria annulus.

-Tim.

[djellison]

Can there be a "restricted sol" with 2 orbiters relaying data?

MRO isn't doing MER relay at the moment as I understand it.

Restricted sols are not a symptom of relay schedules however. Odyssey will usually get a good pass in most days at about 4pm, MRO would get one (if used ) at about 3pm local.

The restriction is a symptom of rover-night and pasadena-day being out of sync. i.e. you have to start planning for Sol N+1 before you have the data for Sol N. Sol N's data can only be used for planning Sol N+2

So - as a result, everything sort of takes twice as long as you might expect. Tie that in with the fact that they didn't get post-drive imagery down until the sol AFTER the first drive, then you can see how the days add up.

[BrianL]

A fast couple of months, then it's going to be painfull.

No, it's going to be wonderful. We have a long term goal again and we should savour each and every day that we are given to share on this journey. There will be days of tension and exhilaration, of confusion and outright boredom. We will see frustration for both the "Why are we stopping to look at this?" and the "Why didn't we stop to look at that?" crowds. I picture Tesheiner hunched over at his computer peering at polar projections and trying to match them up to HiRISE pictures to plot locations. I see anaglyphs from Stu of every rock and ripple we pass, with the occasional poem tossed in to keep things in the proper perspective. Our many route mappers will continue to show Paolo and the other drivers the way, and occasionally there will be instances where they will appear to have followed our advice. The image magicians will poke and prod at the handful of pixels that are the distant rim segments to try and pull details out. There might even be another beacon.

82 days? I'm looking forward to months of free entertainment. It doesn't get any better than this.

[Stu]

Okay...

I've been working on this for a while, time to set it free...

Some of you will like it, some of you will hate it. Fair enough. It's what I feel.


ENDEAVOUR CALLS…

What once was a beguiling, beckoning bowl –
A gargoyle-edged hole carved in the great
Meridiani Plain – is now falling far behind;
A rapidly-thinning line drawn between the high
Cathedral dome of Mars’ pastel-pink sky
And the pebble-spattered, track-trenched
Ground. What we found down there,
On the cliff-shadowed slopes of fair Victoria
Made us stop and stare in wonder:
Rocks sculpted into sheaths of brittle, broken blades
By millennia of dust-drenched wind;
Slanting shafts of sunlight shining
On the sea of sand dunes at its heart;
Book-leaf layers of ancient stone, glowing
Amber and gold as twilight faded to night…
What memories we leave behind..!

But on the flat and far horizon now
A new adventure calls, and if the fates allow,
If an already-weary rover’s battered body
Can somehow find the strength to carry on
For one more stolen year, one sol Opportunity will hear
Us scream and shout out in delight at the impossible sight
Of Endeavour’s Mordor hills looming up before her eyes.
And then, content, we will smile, re-living each heroic mile
Before telling Oppy “That’s far enough. Rest now, little one,
Your work is done.” And then, at last, she’ll sleep
A deep and dreaming sleep, with History as her pillow.
And here on Earth we’ll celebrate a noble rover’s
Journey across the endless dry and rippled sea
of the Great Plain of Meridiani.

© Stuart Atkinson 2008

[mhoward]

I love it, Stu.

Tim53, that image is now on my desktop.

The Navcam view on Sol 1666 is iconic. Here is a partial QuickTime VR (1.7 MB).

The Pancams are also great, but I'll let somebody else deal with those...

[djellison]

No, it's going to be wonderful.

Yeah, you were not here for Purgatory ripple. The adventure is wonderfull. The journey great, but, some of the footsteps can be very very painfull indeed.

Show of hands for those who enjoyed the stop-over at Purgatory and Olympia......wow - no hands

I see what you're saying - but it's not going to be like a path of joy the entire way.

Doug

[centsworth_II]

I see what you're saying - but it's not going to be like a path of joy the entire way.

Aren't you optimistic that Opportunity's new roving software will really shine and allow for a nearly trouble-free trip? Certainly no Purgatorys will be allowed. Maybe an aborted drive every now and then. One is not crazy to hope for this much, no?

[marsophile]

http://qt.exploratorium.edu/mars/opportuni...23P1818L0M2.JPG

Any idea what the odd feature in the sky (top left) is?

[ustrax]

I see what you're saying - but it's not going to be like a path of joy the entire way.

Great words from BrianL...
Wonderful indeed, each and every one of us as part of the original Endeavour crew, facing challenges and delighting us with moments of pure beauty, exploring unroved ground...
The journey...the journey! Not the arrival!

Doug, it could not possibly be a path of joy the entire way...because, simply, that is not the nature of the Epics!

Of course we can think that getting stucked for too many sols is a dreadful think to happen but...at this distance...would the road to Victoria have been the same without Purgatory? Doug, it could not possibly be a path of joy the entire way...because, simply, that is not the nature of the Epics! These require Drama!

EDITED: Stu, fantastic poem, but..."rest now little one..."?!
I thought you had learned something in the last days about Oppy's powers to surprise us...by then she'll be, not trekking, but flying her way out of Endeavour...

marsophile...looks like the first martian attempt to launch a rover towards Earth was successful!

[Tesheiner]

The Pancams are also great, but I'll let somebody else deal with those...

I can only do a quick stitch of that mosaic.


This was a "drive direction" mosaic, meaning that the plan is to go on that direction. "Cape Victoria" might be our next stop and the view from here towards Cabo Frio, Verde, St Mary should be impressive.

[Ant103]

Yes, it should be

360 degree view on Sol 1664 (anyone is thirsty ) :


And the 1666 non-complete view, the same as the -beautiful- Michael Howard pan

[stewjack]

http://qt.exploratorium.edu/mars/opportuni...23P1818L0M2.JPG

Any idea what the odd feature in the sky (top left) is?

It looks like the antenna on my desktop weather alert radio. I don't actually believe that is what it is, but I wanted to get the ball rolling.

Jack

[climber]

I tried to correct the penultimate rhaz. Here it is.
Paolo

Thanks Paolo, so you're not only driving, you can manage imagery!
Well, anyway, I'll be more confortable if you stay focused in the drive dirrection instead of the rear

[climber]

The journey...the journey! Not the arrival!

Endeavour is SO big that even when we'll "arrive", we'll not be there yet. From now on, it's going to be ONLY a journey Rui, only a journey

[Paolo Amoroso]

Well, anyway, I'll be more confortable if you stay focused in the drive dirrection instead of the rear

At times it's safer or easier for the rovers to drive backwards.


Paolo Amoroso

[RoverDriver]

Thanks Paolo, so you're not only driving, you can manage imagery!
Well, anyway, I'll be more confortable if you stay focused in the drive dirrection instead of the rear

I am focussed on driving. That specific image was captured to visually inspect the tracks before turning the vehicle to a heading that would maximize uplink to Odyssey.
Knowing what heppened on the previous drive will help in setting up the next one. In this specific image, clean track, no signs of sinkage, Opportunity was sober.

Paolo

[RoverDriver]

At times it's safer or easier for the rovers to drive backwards.


Paolo Amoroso

True. In what instances it is best to drive backwards?

Paolo

[djellison]

Uphill, or when either front wheel is locked

[Tman]

http://marsrovers.jpl.nasa.gov/gallery/all...FP1997R0M1.HTML

[marsophile]

http://qt.exploratorium.edu/mars/opportuni...23P1818L0M2.JPG

Any idea what the odd feature in the sky (top left) is?

The feature also appears in

http://qt.exploratorium.edu/mars/opportuni...23P1818L0M1.JPG

so it is not a cosmic ray hit.

It looks like it could be a rock being blasted into the air on a ballistic trajectory by a nearby meteor strike, however unlikely that may be.

[djellison]

No - those two images are one and the same - the M1 at the end is the first produced version of that image. If a piece of it doesn't come down, or comes down again, they make an M2 version or M3 etc etc.

http://qt.exploratorium.edu/mars/opportuni...23P1818R0M1.JPG
and
http://qt.exploratorium.edu/mars/opportuni...3P1818RL0M1.JPG

Were taken at the same time - and the feature is only in one - so it is an imaging artifact, not a real object.

[ustrax]

An image artifact?
And here I was thinking that crazy swiss rocketman had made it this far...



Are you sure Doug?...

[PaulM]

True. In what instances it is best to drive backwards?

Paolo

I remember reading that it was thought that one of Spirit's front wheels developed a problem because the front wheels on Rovers are most highly stressed. I thought that for this reason that during Opportunity's trek to Victoria it was decided to alternate between driving forwards and driving backwards every few SOLs to even out the wear on Opportunity's 6 wheels.

Am I correct?

[centsworth_II]

...it was decided to alternate between driving forwards and driving backwards every few SOLs to even out the wear on a Rover's 6 wheels.

Because, I think, it ensures even distribution of lubricant.

[climber]

The Speedy Turtle striked again...

[ElkGroveDan]

I'll say it's a large wooden badger flying off a catapult.



Run away! run away!

[djellison]

Clearly a donkey leaving a trebuchet.

[RoverDriver]

I remember reading that it was thought that one of Spirit's front wheels developed a problem because the front wheels on Rovers are most highly stressed. I thought that for this reason that during Opportunity's trek to Victoria it was decided to alternate between driving forwards and driving backwards every few SOLs to even out the wear on Opportunity's 6 wheels.

Am I correct?

I think that the rocker bogie system is designed to equally distribute the load on all 6 wheels on flat terrain. The reason for switching between forward and backward driving was to equally distribute lubricant and wear.

Paolo

[RoverDriver]

Uphill, or when either front wheel is locked

Correct! I will come up with some more trivia.

Paolo

[BrianL]

I've been thinking for awhile that Paolo needs a special status more befitting than Junior Member and now I have it...

Quizmaster!

[RoverDriver]

An image artifact?
And here I was thinking that crazy swiss rocketman had made it this far...



Are you sure Doug?...

This is a consequence of of our fast driving. It is a pebble that was squashed between one of the wheels and the terrain.

Paolo

[mike]

Were taken at the same time - and the feature is only in one - so it is an imaging artifact, not a real object.

Out of curiosity.. What sort of things would cause this in particular to appear in an image?

[CosmicRocker]

The file with "25cm" in the filename is at the full resolution of the HiRISE mosaic. The Navcam overhead is rendered at 1cm/pixel for the planning tool, but unless folks can open something like Jpeg 2000 format, putting a 1cm/pixel zoom of the map on the rover website would be difficult. Easy to produce, though. ...

Thanks, Tim. Although I couldn't see any file name containing "25 cm," my observation was in error. I was using someone else's computer last night and it apparently had a very old or faulty monitor. Now that I am back on my machine, the maps look great. I was certainly not trying to suggest that we needed 1 cm/px route maps.

... the "purgatoids" ...

I love it! I am going to work very hard to add that word to my vocabulary.