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Posted by: Tesheiner May 20 2009, 08:25 AM

I think it's time for a new thread.
Opportunity is leaving the area where Kasos and other targets were "sniffed" and imaged, making a 20m drive westwards during sol 1891. Besides, we are reaching the 16km milestone.

Here's a Q&D "post-drive" navcam mosaic.

Edited: we are in "restricted sols", right?

Posted by: djellison May 20 2009, 09:40 AM

Quality and detail?




ONWARDS!

Posted by: Tesheiner May 20 2009, 10:22 AM

> ONWARDS!

Rui / Ustrax, did you hacked Doug's account?

Posted by: SFJCody May 20 2009, 11:21 AM

It will be interesting to see what route they take for the next few km. If they stick with driving on rocky terrain whenever possible they will make a big detour to the south west and still have to get across some nasty looking ripples when they move east. On the other hand if they cut east fairly soon they will avoid the bad ripples but have to cover a long distance without firm bedrock beneath the wheels.

Posted by: Tesheiner May 20 2009, 12:26 PM

I was doing the same questions since we continued SSW after the first science stop.
Right now, I think the path will be over rocky terrain; still SSW for some 700m and then E / SE another 500m or so. The problem, as you said, is after that.

Posted by: ElkGroveDan May 20 2009, 01:29 PM

Once this last patch is cleared though, it's clear driving for most of the remainder. That is going to get exciting.

Posted by: Tesheiner May 20 2009, 03:51 PM

Mmm, no answer so I'll try to do the math by myself...

<speculation mode on>
Images/data from sol 1891 were downlinked around 05:30UTC so very late night at JPL. That data will be waiting the whole night (*) until early morning in California when they will be processed by the MER team during the morning shift.

(*) Meanwhile, we at UMSF are already making mosaics, discussing about the future path, etc.

<speculation mode at maximum>
Data/sequences for the next drive should be ready for uplink after one shift (six hours), around 12:00PDT or so. That will be 04:00 local time @ Meridiani, early enough for the rover's morning uplink session.

So, we are NOT in restricted sols. It's time to

<speculation mode off>

Posted by: SFJCody May 20 2009, 08:21 PM

Looks like you're right!

Posted by: RoverDriver May 20 2009, 11:09 PM

How did you know? *I* did not know that I would be done with the sequence by noon today! And I was the RP2 today!!!

Paolo

Posted by: BrianL May 21 2009, 03:53 AM

Paolo, some of these guys know so much you'll probably have to kill them at some point. Not me, of course. I'm woefully ignorant. Just want to be clear on that.

BTW, will you be able to provide us inside info on how the sandbox testing is proceeding, or is that not for public consumption? Yes, I know, that question should be in the Spirit thread, but I got lazy.

Posted by: RoverDriver May 21 2009, 05:17 AM

http://www.unmannedspaceflight.com/index.php?s=&showtopic=5999&view=findpost&p=140816

Posted by: Tesheiner May 21 2009, 05:57 AM

You know I didn't!
My only source of information on this subject is Scott's blog (http://marsandme.blogspot.com/) about Spirit's early sols. I would be really grateful if you could provide us a brief (or not so brief ) description of what is an usual working day for an RP.

Posted by: RoverDriver May 21 2009, 07:28 AM

That's a good question. A good description of the uplink process can be found in:

"Working the Martian night shift - the MER surface operations process" by Mishkin, A.H.; Limonadi, D.; Laubach, S.L.; Bass, D.S.

and

"From prime to extended mission : evolution of the MER tactical uplink process (2006)" by Michkin, Andrew H., and Laubach, Sharon.


Paolo

Posted by: Tesheiner May 21 2009, 08:15 AM

> Sorry for the length of the post ...

What! The lengthy the better, IMO.
I'll need some time to go through it...

---

And back to "back seat driving mode", I've just checked the data to find that today's drive has already finished beind covered 70+ meters. That places the 16km milestone right at the current position (or perhaps a few meters behind).

Here's the latest navcam mosaic looking due south.

Posted by: Tesheiner May 21 2009, 01:41 PM

Finished reading it, and really enjoyed. Many thanks for this detailed description!
A few questions:
- I suppose the beginning of a shift is conditioned to the downlink time, right?
- All this teams, meetings, peer reviews, are duplicated one for each rover? I assume yes.

Posted by: RoverDriver May 21 2009, 02:07 PM

Yes start of shift depends on downlink time and each rover has its own team that go through the meetings and review process.

Paolo

Posted by: HughFromAlice May 21 2009, 09:22 PM

Thanks Paolo, I found your posts v interesting. It's easy to forget just how amazing and complex all this is. A good reminder of how alert all you guys need to remain and how intricate planning and procedure has to be to make sure things are right and that there is max cross checking to ensure that there are no boo-boos! ..........Even just bumping a couple of metres. There's no "just going for a spin on Mars"!

PS - I seem to remember that Emmenthal has lots of holes in it!!!

Posted by: Astro0 May 22 2009, 04:35 AM

Tesheiner: That places the 16km milestone right at the current position...

I like the ground view of your 16km marker.

Posted by: nprev May 22 2009, 05:00 AM

...I knew those labels had to be huge on the ground despite the resolution of HiRISE!

Posted by: Tesheiner May 22 2009, 05:39 AM

Good laugh

Could someone enhance/zoom the horizon? I can see some bright pixels right there; may be the 17km mark.

Posted by: Nirgal May 22 2009, 10:35 AM

good to see her moving towards the goal again

(and glad that the weeks-long-Moessbauer-Integration part apparently must have been skipped this time

Posted by: Ant103 May 22 2009, 01:59 PM

Ha ha ha Astro0 Very nice.

I've made a true 16 km milestone

Posted by: ugordan May 22 2009, 02:04 PM

Hmmm.... a milestone with kilometers on it...

Posted by: jamescanvin May 22 2009, 02:52 PM

Talking of miles, we must be pretty close to the 10 mile post. (Only 93m past 16km, and we did 70 odd of those tosol)

Posted by: jamescanvin May 22 2009, 03:32 PM

Here is the sol 1892 colour (R21) drive direction mosaic.

http://www.nivnac.co.uk/mer/index.php/b1892

Posted by: Ant103 May 22 2009, 03:54 PM

And my version
http://www.astrosurf.com/merimages/opportunity-2009.html#last

Posted by: BrianL May 22 2009, 05:14 PM

Ooh, that looks far too much like a headstone for my liking.

Posted by: BrianL May 22 2009, 05:19 PM

I'm reminded of this gem from Scott's blog:

This sol we had another 48 meter direct drive, the mid-drive survey and localization remote sensing, and then 47 m of
driving using auto-navigation. The total was 95.2 meters, bringing the mission total to 1830 meters. Nextersol, we
should break one Earth nautical mile, which is 1852 meters. As we drive another kilometer and change to the base of the
hills, we will continue to bring you as many arbitrary numerical achievements as we can come up with.

Posted by: ilbasso May 22 2009, 10:58 PM

One or two more drives and we'll be over 10 miles! Go Baby Go!!

Posted by: climber May 24 2009, 08:19 PM

Remember, the more Emmenthal you have, the more holes...but the more holes...the less Emmenthal

Posted by: Phil Stooke May 24 2009, 09:37 PM

The holes are where the blueberries have dropped out...

Phil

Posted by: ngunn May 24 2009, 10:48 PM

I got my Phil,
On blueberry hill . . .

Posted by: helvick May 24 2009, 11:05 PM

That's possibly the funniest post I've read here in a very long time. Classic.

Posted by: nprev May 25 2009, 01:59 AM

...DEFINITELY a strong contender for the annual Worst Pun on UMSF award!

Posted by: BrianL May 25 2009, 05:44 PM

Well, baby is technically going, but not really in the spirit of the phrase (we'll just ignore that unfortunate choice of words).

Looking at Oppy's history since setting out from the rim of VC, she was pretty steady on 30-35 sols per km for the first three km (if we ignore that pesky conjunction layover that was forced upon her). The last one though took over 70. Obviously, for good reason, losing a wheel would certainly slow that pace even further. And in addition to wheel rests, there were a couple of unfortunate delays that perhaps made for an unusually slow transit.

Paolo, do you think the pace of this past km is indicative of what we will see the rest of the way (barring further mishaps, touch wood), or does Oppy still have a chance at picking things up and reaching Endeavour within your original hoped-for timeframe?

Edit: Sorry, this should go in the discussion thread. Could someone all-powerful move it there for me, please?

Posted by: alan May 25 2009, 06:56 PM

Oppy's average rate of travel over 1897 sols = 0.5895 furlongs per fortnight

Posted by: CosmicRocker May 26 2009, 05:13 AM

That sounds http://www.google.com/search?q=16+km/(1892*24.65)hr+in+furlongs/fortnight. I apparently didn't use the same data as you, but it would have been easier to check if Google's calculator, or I, knew the exact length of a Martian sol.

Posted by: alan May 26 2009, 02:20 PM

I used martian fortnights, so no conversion of sol to days needed.

ETA: looks like another drive tosol.

http://nasa.exploratorium.edu/mars/opportunity/rear_hazcam/2009-05-26/1R296591307EFFA1W1P1311R0M1.JPG

Posted by: redmoon May 26 2009, 05:26 PM

Oppy has passed the 10-mile mark tosol.

http://twitter.com/MarsRovers/status/1924611977

Posted by: Oersted May 27 2009, 12:34 AM

Congrats on the ten miles! (Even though I think we should relegate "miles" to the past...)

http://www.space.com/missionlaunches/090526-opp-10-miles.html

- Right now I'll be more excited by ten centimeters by Spirit than another mile by Oppy, though...

Posted by: serpens May 27 2009, 06:38 AM

But that is only 8.7 nautical miles so she still has a way to go.

Posted by: briv1016 May 27 2009, 08:10 AM

Keep in mind that the definition of a nautical mile is the great circle distance corresponding to a 1 degree change in latitude. Because Mars is smaller than Earth, the distance will be less.

Posted by: djellison May 27 2009, 08:23 AM

It's one minute, not one degree - and on Mars, it's JUST under 1km.

Posted by: briv1016 May 27 2009, 06:24 PM

I stand corrected.

Posted by: imipak May 27 2009, 08:02 PM

Clearly, where α is awesome,

Op ≥ 10α

Posted by: climber Jun 2 2009, 09:12 PM

Wondering if those regular 70m drives have something to do with the RF lubrication issue?

Posted by: fredk Jun 2 2009, 09:46 PM

I think the answer is yes. From http://www.planetary.org/news/2009/0531_Mars_Exploration_Rovers_Update_Spirit.html

Posted by: SpaceListener Jun 2 2009, 10:21 PM

However, it is possible to advance two hops of 50 meters each one after a pause of 2-3 hours to cool things?

Posted by: Tesheiner Jun 2 2009, 11:02 PM

Probably yes, but in that case the evening communication session would be missed, I'm afraid.

Posted by: RoverDriver Jun 2 2009, 11:37 PM

2-3 hours won't do much. Over the Memorial Weekend we had a 4 Sols pause and the RF currents came downa bit just to jump right back at the same level. I think we just have to live with it.

Paolo

Posted by: Nirgal Jun 3 2009, 07:47 AM

Yes that seems like a sensible approach that ensures slower but sure & steady progress ... 50 meters at each driveable sol plus keeping the intermediate science stops short (like one week instead of 4+ weeks thus sparing the more complex science tasks and IDD hardware wear for the ultimate loooong science stop at Endeavour

Posted by: Tesheiner Jun 6 2009, 12:55 PM

The http://marsrovers.jpl.nasa.gov/mission/status_opportunityAll.html#sol1900 has some tidbits related to that 30m drive and the current strategy:

Posted by: RoverDriver Jun 6 2009, 02:05 PM

RF wheel currents were beginning to trend upwards again so the drivers on shift decided to start driving backwards again and rest for a while.
There is some challenging terrain about 500m ahead and we will have to sit and think which way to go. This next resting period will come in handy for that.

Paolo

Posted by: SFJCody Jun 7 2009, 10:16 AM

It does look tricky. My favourite route at the moment would be something like this, using patches of bedrock to move east and moving south when in areas where the drift material looks dangerous.

Posted by: RoverDriver Jun 7 2009, 01:54 PM

How about that! We are considering a path similar to that one but most of the drivers prefer a path that goes all around (westward) the area of Purgatoids that is just south of the rover.

Paolo

Posted by: BrianL Jun 7 2009, 03:23 PM

To my eye, angling south-west now, then proceeding close to the edges of the HiRISE photo south then east seems to offer the cleanest route to the really nice looking terrain in the eastern third of the shot. Is that the way being favoured?

Posted by: RoverDriver Jun 7 2009, 03:32 PM

Yes. Still the route has not been decided yet. We will use the next resting period to analyze the HiRISE in detail and come to a conclusion on which route to take.

Paolo

Posted by: climber Jun 7 2009, 04:42 PM

So, you don't trust Rui's! Realy?

Posted by: Tesheiner Jun 7 2009, 04:48 PM

> the next resting period ...

Is it at that outcrop 200m to the south?

Posted by: RoverDriver Jun 7 2009, 05:17 PM

No, I think we will stop at the end of the next drive. Wherever that might be.

Paolo

Posted by: Nirgal Jun 7 2009, 07:32 PM

if I remember correctly, the increase in RF currents was less pronounced (or even non-existant) when driving on firm bedrock in the past (Paolo, correct me if I'm wrong) ...

Posted by: Poolio Jun 8 2009, 02:01 AM

What is the reasoning behind this? Is it due to excessive concern over the RF wheel currents, or because the future path alternatives diverge at this point? The reason I ask is that I would have thought it a priority to reach bedrock before stopping for any length of time (to maximize the science return during the rest).

Mike

Posted by: RoverDriver Jun 8 2009, 02:28 AM

The only thing that helped reducing the RF current now seems to be resting for a week or two. The higher wheel currents indicate that the motor is subject to more mechanical resistance. I have not been following MER-B closely but was told that the nearest bedrock is about 200m away. At the current rate that would be about one week of driving.

Paolo

Posted by: jamescanvin Jun 8 2009, 10:05 PM

Just catching up a bit. Drive direction mosaics for sols 1897 to 1904 (all images link to the same blog entry)

http://www.nivnac.co.uk/mer/index.php/drive_1897-1904

James

Posted by: SpaceListener Jun 9 2009, 02:36 PM

I am suppossing that by driving on bedrock, the wheels traction will require less mechanical resistance than over the sand. Is there any difference of wheel currents between bedrock and sand?

Posted by: RoverDriver Jun 9 2009, 03:11 PM

The RF currents drop to almost nominal (~50% reduction) on bedrock but all other wheels change only a slight amount (10% reduction).

Paolo

Posted by: Nirgal Jun 9 2009, 08:56 PM

Ah, this is very encouraging ! suggesting the RF problem will be greatly alleviated once we reach the firmer "parking-lot" type of terrain about 2 kms ahead (which is expected to be similar in driveability to the "easy" ground between Eagle and Endurance) ... so it sure is the most sensible approach to drive defensively in order to reach the "parking lot" with an intact RF

Posted by: Floyd Jun 9 2009, 11:44 PM

I thought I was looking at Spirit tracks. What the .... salts or silica in the middle of nowhere

Posted by: RoverDriver Jun 9 2009, 11:53 PM

Funny, isnt' it? The penultimate drive tripped the average wheel current limit which is in place to stop the rover when it is close to being embedded. This is the first time this limit was triggered while not extricating the rover from an embedding event. Looking at the tracks, I think this was a good thing.

Paolo

Posted by: Astro0 Jun 10 2009, 04:56 AM

That's very interesting and very pretty

Posted by: nprev Jun 10 2009, 05:35 AM

Hmm. I see some apparent slip marks in the white patch. Given the wheel current spike, is the white stuff therefore more slippery than standard soil?

(And does this hold any clues for Spirit's situation? How many kinds of white stuff have been noted to date over in Gusev?)

Posted by: Shaka Jun 10 2009, 06:41 AM

The little sliver of white to the upper left of the tracks suggests that we have ventured onto standard Meridiani bedrock with a very thin cover of sand.

Posted by: briv1016 Jun 10 2009, 07:11 AM

Looks too clumpy to be just bedrock.

Posted by: Floyd Jun 10 2009, 10:08 AM

No I would agree with briv1016 that it is not bedrock. I think we hit a patch of crumbly salt nodules. I think the larger rock/patch would also crumble if driven over. Paolo also indicated that wheel current was up from moving over/into soft soil--I don't think you would get that with a thin layer of sand over bedrock.

I wonder if Opportunity will do any IDD work to explore the composition of the light material?

Posted by: fredk Jun 10 2009, 02:17 PM

I don't see any sign of slippage in these images. The linear wheel track on the right isn't defined as well where it goes over the messy tracks from the turn in place. The lighter patches may just be patches where the compacted smooth fine soil is catching reflections of sun/skylight?

Posted by: centsworth_II Jun 10 2009, 02:23 PM

I certainly would be good to have something interesting and useful to do during a lengthy rest stop.

(If we're starting a powder vs bedrock debate , put me down for powder -- I hope it's not just wishful thinking.)

Posted by: Shaka Jun 10 2009, 11:22 PM

I'm wishing for the same thing, Cents, but after so many miles of bedrock without a speck of 'powder', I have to play the percentages.

Posted by: marsophile Jun 11 2009, 12:13 AM

Since we seem to be stopped in "DuneLand" for a while, perhaps we should investigate a dune a little more closely. We could perhaps penetrate a dune with the IDD and do some work inside the dune and/or at the point of penetration. Or would this possibly damage the arm?

Posted by: Floyd Jun 11 2009, 12:30 AM

You don't use the IDD for poking. But hey, when was the last time Opportunity dug a good trench? Lets dig down and see what's really there.

Posted by: imipak Jun 11 2009, 08:29 AM

Surely, yes. It's the first such white material Oppy's encountered, and it's obviously a very different environment from Home Plate, so we surely have to find out what it is / how it got here, even if there aren't any implications for future drives. How cool that novel observations are still turning up!

Posted by: Tesheiner Jun 11 2009, 11:19 AM

It seems that this site was considered not relevant because Opportunity left the area. There was a drive yestersol (1912) moving the rover 70+ further south.

Posted by: BrianL Jun 11 2009, 12:08 PM

So, as I understand it, this is where we sit and wait to see whether Oppy turns on her left or right turn signal indicator? Good to see some chatter in the other thread about the possible choices. It's been pretty quiet in the back seat for awhile.

Posted by: fredk Jun 11 2009, 03:04 PM

I think we've seen similar "white powder" on Meridiani before. I'm still skeptical it really was "white powder" - it could've been reflectivity rather than albedo.

But we did sit there resting the RF wheel for 6 sols, so maybe they decided the wheel could now survive a couple of sols' drive to the bedrock and then we'll do a longer science stop there?

Posted by: eoincampbell Jun 11 2009, 03:23 PM

Surely trench digging will not be considered given the precocious state of the RF wheel.

Posted by: djellison Jun 11 2009, 03:47 PM

Could always use the FL. I'd expect us to do 1 - 2 more drives to get to the next bit of outcrop before having some down-time to make the decision between left and right.

Posted by: eoincampbell Jun 11 2009, 04:50 PM

I wonder about the extent of the "wear" on the other wheels, (not too far behind RF?) that would determine a "go for trenching".
I thought we would trade the digging(more resistance?) for driving at this stage...

Posted by: djellison Jun 11 2009, 05:46 PM

The other wheels are all reporting normal currents.

Posted by: Tesheiner Jun 11 2009, 06:23 PM

I would expect that too but the plan for tosol has some MIs so perhaps we will be stopped here for some time.

Posted by: ngunn Jun 11 2009, 06:57 PM

. . as stated in post 60, no?

Posted by: SpaceListener Jun 18 2009, 04:33 AM

The Oppy has by far less watt-hours than Spirit.

There is increasing the concern on the RF which is increasing the wheel current.

http://www.marsdaily.com/reports/Opportunity_Has_Elevated_Wheel_Current_Again_999.html

Is there any way to improve the lubrication on the RF? Will the summer time, with the increasing heat might help to improve the lubrication on the wheels?

Posted by: CosmicRocker Jun 18 2009, 05:44 AM

Yes, thanks to recent wind cleanings, Spirit is able to store about twice the energy Oppy is able to each day, but I doubt the extra amps Oppy's labored wheel may consume will break her bank. As I understand it, Opportunity's main concern is the mechanical preservation of that wheel system, not her available energy.

Posted by: serpens Jun 18 2009, 06:25 AM

Just out of interest,did they ever venture an opinion as to what the white deposit of 10 June was?

Posted by: CosmicRocker Jun 19 2009, 05:00 AM

It was apparently nothing of interest, since it was only observed in navcams, and no pancam filters or mini-TES observations of the scene were recorded. As I think was mentioned previously, these navcam-bright materials have been commonly observed in Opportunity's tracks many times before. A recent example was photographed on sol 1886, but this stuff has been seen very often.

I don't recall them ever being officially described or explained, which is why I assume they are a phenomenon well understood and of little current interest to the team.

Posted by: ustrax Jun 19 2009, 09:30 AM

According to Tesheiner's latest map I would dare to say that we are in great conditions to meet the estimated arrival date to my reference location or even get there earlier...let's see! Step by step...

Posted by: Tesheiner Jun 19 2009, 10:32 AM

That's because Opportunity took a short cut

We are almost at that big outcrop, less then 100m to reach it. And the big question is (hello Paolo!): left or right? Have a decision already been made about it?

Posted by: ustrax Jun 19 2009, 11:30 AM

That leaded to "The Spines"...

Posted by: BrianL Jun 19 2009, 12:47 PM

They sure didn't give any hint on this latest drive. I was hoping to see a fade one way or t'other, but they are maintaining the mystery. Ooh, I love a good page-turner.

Posted by: AndyG Jun 19 2009, 01:44 PM

I prefer a good wheel-turner.

Andy

Posted by: fredk Jun 19 2009, 02:44 PM

This was quite a short rest stop - only 8 sols. Maybe Oppy's eager to see what the next chapter brings too...

Posted by: Tesheiner Jun 19 2009, 03:18 PM

I'm not sure if we're "back on business" or if the last site was just absent of any significant science feature and they decided to move forward looking for cobbles in the vicinity. Let's see what's in the weekend plan.

Posted by: Shaka Jun 20 2009, 07:14 PM

http://qt.exploratorium.edu/mars/opportunity/micro_imager/2009-06-20/1M298459636EFFA312P2976M2M1.JPG
I prefer mine fresh and firm.

Posted by: nprev Jun 20 2009, 07:46 PM

How about dusty, crusty BBs instead? They look coated to me.

Posted by: ElkGroveDan Jun 20 2009, 08:11 PM

I don't believe those are BB's at all. More like clumped particles. Probably some kind of electrostatic cohesion.

Posted by: Shaka Jun 21 2009, 12:04 AM

That's three diagnoses. Any more?

Posted by: BrianL Jun 22 2009, 12:22 PM

Westward ho!
http://nasa.exploratorium.edu/mars/opportunity/forward_hazcam/2009-06-22/1F298896453EFFA3G6P1214R0M1.JPG

OK, maybe I'm reading too much into this little jog.

Posted by: Tesheiner Jun 22 2009, 01:55 PM

A 7m drive towards a nearby outcrop. That's the only reading I will do.

Posted by: fredk Jun 24 2009, 07:47 PM

From the http://marsrovers.jpl.nasa.gov/mission/status_opportunityAll.html#sol1913

I would've thought you'd need a pretty severe seismic event to show up on the accelerometers. Has this been tried before?

Posted by: Poolio Jun 24 2009, 08:05 PM

The latest http://marsrovers.nasa.gov/mission/tm-opportunity/opportunity-sol1923.html indicates that an extension of 2.8 km has been added to the total odometry to reach Endeavour. Instead of 16.2 km, the target is now 19.0 km. I expect this means that they have settled on the westward route.

Posted by: BrianL Jun 24 2009, 08:13 PM

Or they're planning on an awful lot of zig-zagging on the east route.

Posted by: Tesheiner Jun 24 2009, 08:26 PM

Good catch, Poolio!

Posted by: RoverDriver Jun 25 2009, 02:09 AM

That is correct. The route has been named "pink route".

Paolo

Posted by: BrianL Jun 25 2009, 03:21 AM

Is there an official map for the proposed pink route?

Posted by: RoverDriver Jun 25 2009, 04:57 AM

Yes there is, but I will let Tim Parker talk about it.

Paolo

Posted by: algorimancer Jun 25 2009, 03:49 PM

First I've heard of it. I proposed giving it a try some time back (years ago, I think) and as I recall no one thought it was feasible. I'm glad to hear that they're trying. Seems like good thing to do when parked on bedrock.

Posted by: CosmicRocker Jun 26 2009, 05:32 AM

It sounds like a fascinating experiment. Do we have any specs on the accelerometer/s involved?

Posted by: Tesheiner Jun 26 2009, 11:25 AM

From the http://marsrovers.jpl.nasa.gov/mission/status_opportunityAll.html#sol1920:

We have already reached it. I'm waiting for visual confirmation but the mobility data tells us today's drive was aprox. 60m, placing Opportunity on solid rock.

Posted by: JayB Jun 26 2009, 03:43 PM

very odd (blueberry?) dune formation here

http://qt.exploratorium.edu/mars/opportunity/pancam/2009-06-25/1P298890508EFFA3EZP2370L5M1.JPG

Posted by: stewjack Jun 26 2009, 07:10 PM

I have no suggestions, but it looks "odd" to me also.

Posted by: Tesheiner Jun 26 2009, 09:17 PM

To put the picture into context, here's the corresponding navcam shot:
http://qt.exploratorium.edu/mars/opportunity/navcam/2009-06-19/1N298633609EFFA3EZP0705L0M1.JPG

Posted by: lyford Jun 26 2009, 10:11 PM

Could that be a depression instead of a dune? In the navcam it looks like there are a few more to the right and up a bit....

But then again, I always have the crater/dome problem when looking at orbital pics.

Posted by: tim53 Jun 26 2009, 10:28 PM

I'd be happy to talk about it, though I'd like to be sure that the rest of the team, particularly Steve, is okay with it being posted to the public. The primary reason it might not be, if I have this right, is so as not to give the impression that we're bound to a particular path - that we wouldn't be flexible if we found something unexpected (either about the terrain or the vehicle).

But yes, the engineers asked us to look into a westward route around the purgatories. I had, some time ago (like many of you), but at the time I think we all thought that the bigger concern was number of wheel rotations, not total mileage. Now, it looks like time is a bigger factor, and projections are that even though this is a longer drive, it's potentially simpler and thus less time-consuming than going through the "Isthmus".

-Tim.

Posted by: BrianL Jun 27 2009, 05:03 PM

I would hope that releasing it as a possible route would cover you. Crossing fingers now.

Edit: Just to be clear, I'm using "you" in the plural sense, not suggesting that you (singular) should do anything other than what the team decides.

Posted by: RoverDriver Jun 28 2009, 12:05 AM

Tim, I did not mean to put you in the hot spot. This is exactly what I meant to say. We don't want to get into trouble for releasing information!

Paolo

Posted by: tim53 Jun 28 2009, 01:36 AM

No worries Paolo. I don't think we'd get in trouble for releasing information, just if we mean one thing and had it misinterpreted, is all.

Does that make any sense?

See you on Mars!

-Tim.

Posted by: nprev Jun 28 2009, 03:23 AM

Don't worry, you guys. All hard-core UMSFers are bound by a code of silence; we won't blab!

It's not like this site was on the Internet, much less the #1 hit on Google for its topic or anything...oh, wait...

Posted by: BrianL Jun 28 2009, 06:05 AM

Well, that's not entirely true. You pretty much have to type in "unmanned spaceflight" to have any chance of Google returning UMSF.com on the first page of results. So really, this is a pretty obscure place. Billions upon billions of people in the world are not even aware of the existence of UMSF so if you want to release some inside info and still keep it from the masses, I think this is the place to do it. Seriously, maybe 20 people, 30 tops, read this forum. Go ahead, spill the beans.

Posted by: RoverDriver Jun 28 2009, 07:06 AM

You just need one JPLer tattling and you are in trouble. Happened to me, don't want to have Tim in the same spot.

Paolo

Posted by: Astro0 Jun 28 2009, 07:23 AM

RoverDriver.... A question:
Is it possible to put the brakes on the RF wheel only and still drive?
Would it be possible to still make progress while effectively resting the wheel (trenching) or would the currents still be affected?

Posted by: djellison Jun 28 2009, 08:08 AM

Well, that's not entirely true. Some statistics for you. Google Analytics (CPanel Analog Stats)

May, the last complete month, saw 26,521 (43,394) unique visitors, making 58,691 (88,506) visits, and viewing 273,619 (516,096) pages. Of those visits, google report 20.8% came from search engine results.

It's also on the first google page for things such as
meteor hitting earth
what colour is uranus
europa lander
fastest spacecraft
google mars 3d
what happened to mars pathfinder
phobos grunt
saturn map
hirise 3d
hirise dem
and...
rover route map

nprev, brian (and others).... Tim and Paolo (and others) are going way over and above the call of duty in giving us as much time as they do, and sharing as much information as they do. Please don't encourage, pressure or egg them on in providing anything more than they feel is appropriate.

Posted by: nprev Jun 28 2009, 08:16 AM

To be clear, I was just teasing them a bit, but it's a point well taken, Doug.

I would absolutely never encourage any of the esteemed (and greatly appreciated) professional forum members who are kind enough to share their always fascinating insights here to disclose anything that might compromise their professional ethics or that would endanger their careers, or in any way harm or even embarrass their programs or colleagues. I fully understand and support their need for discretion, and certainly hope that others feel the same way.

[EDIT] Should also point out that Brian was being facetious as well. We both elliptically alluded to the fact that UMSF is a (perhaps the) Google hotspot for all searches related to the cutting edge of the planetary sciences these days, and therefore most certainly NOT the place to post anything best left confidential in the field!

Bottom line: I pulled a leg, Brian came along & helped me, and between us it came off in our hands! My apologies to all for instigating this, and there was no harm intended. Will be more careful in the future. [/EDIT]

Posted by: RoverDriver Jun 28 2009, 01:51 PM

The vehicles do not have real brakes but the gear ratio between the wheel and motor is so high that when the motor is not energized the wheel is essentially unmovable. In case anyone missed it, there is experimental evidence of this fact on the other side of the planet :-P. We can control each individual actuator, so yes we can simply turn off the RF wheel and drive. Regarding how effective that is, this largely depends on the soil properties (sand vs. bedrock) and slope. One of the reasons we chose to drive around the area of Purgatoids is to have more options in case we are forced to disable the RF wheel. Path control with 5 active wheels and one anchor is more difficult, besides being slower, and it would make our lives more difficult being in an area where there are narrow passages or steep slopes. I would probably lose what is left of my hair.

Paolo

Posted by: BrianL Jun 28 2009, 04:35 PM

Yes, what nprev said. Sorry as well.

Posted by: cbcnasa Jun 28 2009, 07:34 PM

Can you use just any one wheel or must multiple wheels be used on the vehicle?

Posted by: HughFromAlice Jun 28 2009, 08:21 PM

The W route makes sense in terms of putting an ageing machine (sorry Oppy!) under min stress for max time. Instead of grinding through/slipping over nasty purgatroidish type dunes the old girl (apologies again!) can keep trundling ( ) along for a long long time. I've tried it with old cars. It tends to work!

Posted by: RoverDriver Jun 29 2009, 03:06 AM

We can command any combination of wheels. Same thing for steering actuators.

Paolo

Posted by: MahFL Jun 29 2009, 01:49 PM

So...is there a pic of the west route available to the public ?

Posted by: bruc Jun 30 2009, 03:34 AM

It looks like something hit the surface at a nearly horizontal angle and pushed all the blueberries off the bare spot into a mound. Maybe it was a chunk of rock from a meteorite impact nearby?

Posted by: CosmicRocker Jun 30 2009, 05:40 AM

Those features are curious. They, and related features have been debated ad infinitum in this forum in in the past. Unfortunately, I don't believe we have ever come to a consensus regarding their origin. I don't recall Opportunity's handlers commanding the rover to dig into them or to otherwise study them with the tools available on the rover.

All I can guess is that these structures are either well understood by the scientists directing the mission, or that such observations are of a low priority to the team.

Posted by: centsworth_II Jun 30 2009, 07:13 AM

I believe the "something" that hit the surface was wind. As already http://www.unmannedspaceflight.com/index.php?s=&showtopic=6022&view=findpost&p=142521 there seem to be other examples of the same phenomenon which I've circled in this crop of the navcam image. I think that a particular combination of substrate, surface material, and wind pattern is the cause.

Posted by: Stu Jun 30 2009, 10:16 AM

Either Oppy's clearing out some old pics or she had a helluva drive backwards overnight...

http://qt.exploratorium.edu/mars/opportunity/navcam/2009-06-29/1N236310443EFF85R9P0694L0M2.JPG

Posted by: Tesheiner Jun 30 2009, 10:24 AM

"Robot dreams" maybe?

Posted by: Stu Jun 30 2009, 10:40 AM

Yeah, I can just imagine Oppy trundling along, daydreaming to herself...

I miss Victoria Crater. There was cool stuff to see there. Those high cliffs... all the pretty-shaped rocks... those dust ripples in the crater's bottom... Now what do I get? Dust dunes as far as the navcam can see... same old same old, sol after sol... I'm sick of it... bored, bored, bored, bored, bored...

(someone give Doug a glass of water, I think I hear him choking! )

Posted by: MahFL Jun 30 2009, 12:57 PM

Those pictures are pretty interesting. It reminds us how close she went to the edges. A testament to the confidence of the Rover Drivers and thier management.

Posted by: BrianL Jul 3 2009, 04:27 AM

Just out of curiosity, how much longer is Oppy planning to stay at the current rest stop?

Posted by: Poolio Jul 3 2009, 05:55 AM

This http://marsrovers.jpl.nasa.gov/mission/status_opportunityAll.html#sol1920 notes that the plan was to position the rover on the outcrop to "rest the mobility system over the coming holiday". So I'm guessing that the earliest we'll see movement is mid-week.

Posted by: Tesheiner Jul 3 2009, 07:05 AM

Or a bit longer, maybe. I see an MB integration in the meantime.

01933::p1131::04::2::0::2::0::0::4::f_haz_idd_mb_doc_512x512x1bpp_vhigh

BTW, a bit of archeology of ancient mesopotamia is also planned.

01934::p2375::20::16::0::0::16::2::34::pancam_humbaba_L7R1
01934::p2376::20::10::0::0::10::2::22::pancam_gilgamesh_L7R1
01934::p2377::20::6::0::0::6::2::14::pancam_enkidu_L7R1

Posted by: Marz Jul 3 2009, 04:57 PM

EXCESS QUOTING REMOVED

Zoiks! A Mössbauer spectrometer soak time is up to what, 12-14 days? I realize it's excellent to get a series of readings as the mission progresses across the terrain, so I'll try to be patient. At least the wheel gets a good rest too, and hopefully the driving will get a bit easier soon.

Posted by: Tesheiner Jul 11 2009, 09:43 AM

FWIW, Opportunity might be finishing this science stop and leaving the area today, sol 1942, taking the western route.

01942::p1212::09::2::0::0::2::0::4::front_haz_ultimate_2_bpp_pri15
01942::p1312::07::2::0::0::2::0::4::rear_haz_ultimate_2_bpp_pri15
01942::p1655::01::10::0::0::10::0::20::navcam_5x1_az_90_1_bpp
01942::p1962::14::10::0::0::10::0::20::navcam_5x1_az_270_3_bpp_bin_17_42
01942::p2381::20::12::0::0::12::2::26::pancam_drive_direction_4x1_L6R12

Posted by: Sunspot Jul 11 2009, 01:06 PM

Is Endeavour still a realistic target? With the limited driving per sol, the problematic wheel/possible wheel failure and the lengthy stops to rest it, and also the new route adding 2 or 3 KM? Is there anything else around that might make a realistic target? Or are we now too committed to Endeavour to get to another target?

Posted by: SFJCody Jul 11 2009, 01:46 PM

There's a freshish big crater 8.7km WNW and a big (but highly eroded) crater 5.7km south but both look like they would just be more of the same old Meridiani sandstone. Endeavour is the only thing around for miles that might show something different.

Posted by: Astro0 Jul 11 2009, 02:08 PM

Sunspot said: Is Endeavour still a realistic target? With the limited driving per sol, the problematic wheel/possible wheel failure and the lengthy stops to rest it, and also the new route adding 2 or 3 KM? Is there anything else around that might make a realistic target? Or are we now too committed to Endeavour to get to another target?

Endeavour is certainly worth going for...the idea is to try. It's not as much a goal as a direction.
Steve Squyres said: "We may not get there, but it is scientifically the right direction to go anyway."

Is reaching Endeavour possible? There is no reason to currently think it isn't.
Yes, Opportunity is getting older, there's potential problems for its long term mobility, but if these Rovers have taught us anything, it's to never say impossible. Add to that...the Rover planners and drivers have 5.5years of experience to draw on, and we know from watching them that they never say impossible either.

Are there other places for Opportunity to go that are closer? Yes! She's driving across it right now.
There'll be plenty of places along the way that will be scientifically interesting and will extend our knowledge of this region.

"I would love to see that view from the rim," Squyres said. "But even if we never get there, as we move southward we expect to be getting to younger and younger layers of rock on the surface. Also, there are large craters to the south that we think are sources of cobbles that we want to examine out on the plain. Some of the cobbles are samples of layers deeper than Opportunity will ever see, and we expect to find more cobbles as we head toward the south."

Will Opportunity reach Endeavour? I hope so. If she doesn't? I for one won't be disappointed, it's been 5+ glorious years of exploring Mars.

Posted by: Vultur Jul 14 2009, 06:02 PM

This may be a stupid question, but...

How is the "resting the wheel" stuff calculated? That is, given that Oppy has a finite lifetime (well, presumably), how was it determined that Oppy has more chance of getting to Endeavour (or, in general, getting more miles in its remaining lifespan) by taking it slower now and resting the wheel, vs. going all out now with 100m+ drives each sol and dealing with 5 wheels if and when that happens?

Posted by: ElkGroveDan Jul 14 2009, 07:26 PM

If I recall correctly they began noticing higher current draws from that wheel at the end of long drives. They also noticed that the currents either dropped or returned to nominal after long rest/science periods. Short rests didn't have much effect on the current draw problem.

Posted by: Nirgal Jul 14 2009, 08:53 PM

I understand your question. I too, have been wondering about the very same thing. i.e. considering the fact that resting days too will probably shorten the 'remaing life-span' because of wear caused by the sharp thermal cyles, the dust accumulation etc. ...

Posted by: ElkGroveDan Jul 14 2009, 09:20 PM

Well to be strictly logical here, there is no statistical data to calculate the odds for complete rover failure on any particular sol for MER flight models. The only data we have is open ended and points to astronomically longer lifetimes than design parameters dictate. With the denominator still being zero the numbers we have at this point dictate an infinite lifetime (strictly speaking). There is however a data set for wheel-failure for an identical vehicle under nearly identical conditions. So in choosing to calculate risk on one or the other, they have to go with the wheel-failure data and work around that.

Posted by: BrianL Jul 14 2009, 09:51 PM

Well, we know they can't last beyond December 21, 2012.

Posted by: eoincampbell Jul 15 2009, 06:15 AM

Is it not all down to the MER teams' pure and utter skill...?

Posted by: djellison Jul 15 2009, 10:23 AM

Subject continued here

http://www.unmannedspaceflight.com/index.php?showtopic=6102&st=20&start=20