Tesheiner
May 15 2008, 02:27 PM
In the
latest status report we could find this:
QUOTE
Tests during the past week included electrical resistance tests at the warmest and coldest times of day to determine if a persistent stall in the joint was dependent on temperature. Test results indicated that electrical resistance in the shoulder motor at the warmest time of day approached normal levels.
Curiously, today's successful move was executed at 09:20am local time (aprox.). I wouldn't call that the "warmest time of day", would you?
slinted
May 15 2008, 03:32 PM
QUOTE (Tesheiner @ May 15 2008, 07:27 AM)
Curiously, today's successful move was executed at 09:20am local time (aprox.). I wouldn't call that the "warmest time of day", would you?
Good point Tesheiner, but if they know from testing that it is a temperature problem, the solution might be as simple as waking up from deep sleep a little early, and letting the stuck heater do its thing.
akuo
May 15 2008, 04:02 PM
I wonder if the heater can still be manually turned on. 9:20 sounds awfully early for a rover to be up though.
Anyway I am very glad about being wrong about my prediction that the motor was finished. Onwards to The Cape!
Del Palmer
May 15 2008, 04:17 PM
QUOTE (akuo @ May 15 2008, 05:02 PM)
I wonder if the heater can still be manually turned on. 9:20 sounds awfully early for a rover to be up though.
I'm afraid the thermostat that brings the heater on cannot be overridden; you have to wait until the minimum setpoint is reached, and then the heater stays on, and on, and on...
climber
May 15 2008, 04:23 PM
QUOTE (Del Palmer @ May 15 2008, 06:17 PM)
I'm afraid the thermostat that brings the heater on cannot be overridden; you have to wait until the minimum setpoint is reached, and then the heater stays on, and on, and on...
I guess we're talking about the stucked heater that will be on as soon as deep sleep is over
brianc
May 15 2008, 05:47 PM
Do you think they will now leave the shoulder so it's pointing as it is now i.e with the upper arm at 90 degress out, surely
driving at such a low speed <1mph is extremely unlikely to cause any damage to the arm or the instruments. I'm very surprised
that they risk stowing the arm before each move.
Floyd
May 15 2008, 11:53 PM
Does anyone have an inside knowledge of the discussions or reasons that led to the policy of stowing the arm for drives, and unstowing it when the drives are completed. I know that they thought that night temperatures (or thermo cycling) might cause a wire to break in the motor, and so they wanted the arm unstowed. What specifically were the fears of leaving the arm permanently unstowed during drives. Can the joints creep--I think not--but what is the gearing--a worm gear? Worm gears can't creep. Doug or some of you engineers need to better explain the working of the arm joints and why it is (somewhat) dangerous to travel with the arm unstowed. Diagrams and pictures would help
-Floyd
fredk
May 16 2008, 12:36 AM
Floyd, your question was addressed in
this rover update:QUOTE
... we're not going to be able to move the joint enough to actually fully stow the arm. So now the problem becomes a driving challenge, in terms of the clearance envelopes for the vehicle given the arm in this configuration, and the second has to do with what forces you put into the arm that might possibly move the arm from its current location. The danger there is not so much that the arm could wobble and return to its current position, but that you put in forces that might cause the actuators to backdrive a bit. When you do that, because we're not actually actuating the arm while we're trying to drive, you've created uncertainties in terms of what your knowledge is of the locations of the joints.
Another thing, which does not affect driving so much, but does affect any further operation of the IDD, is, Matijevic said, that there is "going to be increased difficulty and some uncertainty in the placement of instruments." That, in turn, will limit in some respects the kinds of targets the rover can work with and add additional uncertainty in terms of where the rover is actually taking measurements on the target."
Tesheiner
May 16 2008, 11:13 AM
The last navcam pictures of a big panorama taken during sols 1508 and 1510 were finally downlinked.
01508::p1928::02::20::0::0::20::0::40::navcam_10x1_loco_custom_pri_95
01510::p1929::02::20::0::0::20::0::40::navcam_10x1_loco_custom_lower_tier_pri_95This is not an usual 360º take because in this case the panorama is made of two rows, making for a bigger VFOV (81º instead of 45º), and the raw pictures have LOssless COmpression (LOCO) applied. Here's the result, although there are still some datadrops on the raw images.
Click to view attachmentThe same in polar form.
Click to view attachmentBTW, I haven't seen a polar projection posted here since quite a long time! A Mars bar goes to the person who points to the latest before this one.
jamescanvin
May 16 2008, 12:50 PM
QUOTE (Tesheiner @ May 16 2008, 12:13 PM)
BTW, I haven't seen a polar projection posted here since quite a long time! A Mars bar goes to the person who points to the latest before this one.
This one by Astro? (10th March) Not far from where we are now.
fredk
May 16 2008, 02:01 PM
djellison
May 16 2008, 02:37 PM
No motion of the unhappy-motor to do that though. I would have thought you would want to bring the arm up close to the vehicle so that any jolting has the smallest torque. If it's all stretched out, the jolting would be magnified quite a lot.
Doug
dot.dk
May 16 2008, 02:43 PM
Will we see the return of the elbow out stow on the deck?
They did some test driving with that configuration back then.
http://marsrover.nasa.gov/gallery/all/1/n/...KSP1938L0M1.JPG
Tesheiner
May 16 2008, 02:51 PM
QUOTE (fredk @ May 16 2008, 04:01 PM)
I was never interested on those pictures before, because the forward view was kind of blocked by the IDD.
Now, I'm really happy to see this same picture after these weeks. Hope to be "on the road" soon.
Tesheiner
May 16 2008, 03:02 PM
QUOTE (jamescanvin @ May 16 2008, 02:50 PM)
This one by Astro? (10th March) Not far from where we are now.
Think so. Enjoy it!
fredk
May 16 2008, 06:05 PM
QUOTE (djellison @ May 16 2008, 02:37 PM)
If it's all stretched out, the jolting would be magnified quite a lot.
I'd be surprized too if they actually started driving with the arm in the current position. I imagine they are just doing tests with the arm now, and it will probably be some time still before we start moving again.
djellison
May 16 2008, 07:53 PM
Recent imaging looks to me like they've decided to use the left hand side of the Pancam CCD to avoid the worst of the dust on the lens, to get a really good sharp observation of the exit route.
Doug
centsworth_II
May 16 2008, 07:58 PM
Does this mean the quest to get a better look at the cape is over?
Doc
May 17 2008, 12:07 PM
QUOTE (centsworth_II @ May 16 2008, 11:58 PM)
Does this mean the quest to get a better look at the cape is over?
It looks like it, i mean if u look at the situation right now it is reasonable to think that driving away from the Cape might be a good idea. Besides, apart from spectacular imagery potential, i am begining to think this quest for te Cape is as foolish as a guy trying to fly (apologies for those who were looking forward to seeing the Cape
)
djellison
May 17 2008, 01:03 PM
There's no reason why it is any less or more difficult to get closer to the cape. It's looking very unlikely we could put the IDD up against it, and the driving would be hard, but from what we have infront of us in terms of imagery - I don't think we can say they're not going to go, yet.
I would have thought the reason behind the 'exit site' imagery is because they had time on their hands waiting for IDD diagnosis, and given that if they go up to the cape or not, that's the way they're going out, it makes sense to get great quality imagery of that site now.
Doug
Aussie
May 18 2008, 05:13 AM
QUOTE (Doc @ May 17 2008, 12:07 PM)
i am begining to think this quest for te Cape is as foolish as a guy trying to fly
Otto Lilienthal must be rolling in his grave. I am sure that there is a lot of risk assessment going on, but I hope they go for it.
mike
May 18 2008, 06:11 AM
Why not go for the cape, who knows what's over there? You don't know until you try.
centsworth_II
May 18 2008, 03:05 PM
QUOTE (mike @ May 18 2008, 01:11 AM)
You don't know until you try.
They've already tried once and gotten stuck. The question is,
do they understand what happened and do they think there is
a way to avoid the same problem on a second try.
jamescanvin
May 19 2008, 08:37 PM
QUOTE (djellison @ May 16 2008, 08:53 PM)
Recent imaging looks to me like they've decided to use the left hand side of the Pancam CCD to avoid the worst of the dust on the lens,
Which is good news for us, although it does mean I have a lot more images to sort out!
mhoward
May 20 2008, 04:45 PM
QUOTE (jamescanvin @ May 19 2008, 02:37 PM)
Which is good news for us, although it does mean I have a lot more images to sort out!
I was pleased to see that the new subframe pan works pretty well in MMB. I hope they keep doing it this way; would make things a bit easier for almost everyone (one would think).
dot.dk
May 20 2008, 06:45 PM
A new update on the arm:
http://marsrover.nasa.gov/mission/status.html#opportunity"Injured Shoulder Joint Back in the Game"
A very nice summary of what the story has been on that shoulder joint since SOL 2.
And it will most likely never be stowed again.
I never understood the reason to stow the arm on every little tiny drive.. Tiny drives that I can't imagine would do anything bad to the arm. Instead every drive they weared the joint motor during a stow+unstow. Longer drives over rough terrarin I would understand, but not tiny drives or drives over completely flat ground like around Victoria.
jamescanvin
May 20 2008, 07:01 PM
QUOTE (dot.dk @ May 20 2008, 07:45 PM)
I never understood the reason to stow the arm on every little tiny drive.. Tiny drives that I can't imagine would do anything bad to the arm. Instead every drive they weared the joint motor during a stow+unstow. Longer drives over rough terrarin I would understand, but not tiny drives or drives over completely flat ground like around Victoria.
If you remember, they did experiment with doing small drives back in the 600's when the motor winding broke. The folks in the know, deduced that it could be a problem leaving it deployed and it was worth the risk to stow it. I believe that the thinking was that the motor was likely to fail due to day/night thermal cycling and not through extended use so it probably would have had this problem now regardless, and could have had a bigger problem earlier caused by shaking the deployed arm if the other option had been taken.
climber
May 20 2008, 08:04 PM
I'm astonished to learn again how good JPL engeneer are. The report say 3 times "This strategy worked for Opportunity until Sol XXXX".
I hope it'll work again until Sol xxxxx
Tesheiner
May 21 2008, 08:15 AM
This same status update has an answer to my, obviously incorrect, comment about "warmest time of the day" on a
previous post.
They found that the resistance was lowest (essentially normal) when the joint was at its warmest -- in the morning, following deep sleep, after the heater had been on for several hours, and just before the T-stat opened. They decided to try to unstow the arm one more time under these conditions.I have now the impression that these rovers will stop working only after completely blind and all motors have failed.
BrianL
May 26 2008, 12:32 AM
Awfully quiet in here. Where is everybody?
Brian
mike
May 26 2008, 01:27 AM
Trees on one side, fossils on the other.. they're both good
fredk
May 26 2008, 03:17 PM
Some news about Oppy buried in the flurry of Phoenix stuff at
the PS blog:QUOTE
[Steve Squyres] mentioned they've been doing a lot of work in the testbed with the engineering model, figuring out if it's safe to drive Opportunity with its arm sticking out. He said that they've driven it up and over bricks, slamming the front end to the ground (and he mimed the arm jiggling up and down alarmingly) and the thing hasn't even moved off its calibrated position. So, he said, it's safe to drive, and they're very likely planning on proceeding toward Cape Verde later this week; they'll hold a decision about it on Wednesday.
Tesheiner
May 30 2008, 02:33 PM
While all the attention is focused near the martian north pole, Opportunity is still testing the IDD.
Disclaimer: This is my first attempt to make a movie from still images.
djellison
May 30 2008, 02:58 PM
Wait...we have rovers now?
dot.dk
May 30 2008, 03:39 PM
What kind of testing are they doing right now? Moving the healthy joints in small increments. I'm curios what they learn by doing that
jamescanvin
May 30 2008, 05:00 PM
That has puzzled me too. I can only think that they are calibrating the joints so they can check for any problems more easily after driving with the arm unstowed.
CosmicRocker
May 31 2008, 06:22 AM
QUOTE (djellison @ May 30 2008, 08:58 AM)
Wait...we have rovers now? ...
Haha! rotfl...
ilbasso
May 31 2008, 03:05 PM
They're called rovers...but neither one of them has moved much in the past couple of months!
dot.dk
May 31 2008, 03:40 PM
QUOTE (ilbasso @ May 31 2008, 05:05 PM)
They're called rovers...but neither one of them has moved much in the past couple of months!
Something coming up tosol for Oppy maybe?
From the tracking page:
CODE
01547 p0141.01 0 0 0 0 0 0 navcam_1x1_az_72_1_bpp
01547 p0161.01 0 0 0 0 0 0 navcam_1x1_az_108_1_bpp
01547 p0755.03 0 0 0 0 0 0 navcam_5x1_az_270_3_bpp
01547 p1214.05 0 0 0 0 0 0 front_haz_ultimate_4bpp_pri15
01547 p1242.02 0 0 0 0 0 0 FrRightHaz_wheel_sub_4_bpp_pri_19
01547 p1242.02 0 0 0 0 0 0 FrRightHaz_wheel_sub_4_bpp_pri_19
01547 p1242.02 0 0 0 0 0 0 FrRightHaz_wheel_sub_4_bpp_pri_19
01547 p1242.02 0 0 0 0 0 0 FrRightHaz_wheel_sub_4_bpp_pri_19
01547 p1242.02 0 0 0 0 0 0 FrRightHaz_wheel_sub_4_bpp_pri_19
01547 p1314.00 0 0 0 0 0 0 rear_haz_ultimate_4bpp_pri15
01547 p1342.01 0 0 0 0 0 0 RearLeftHaz_Wheelie_sub_4bpp_pri19
01547 p1342.01 0 0 0 0 0 0 RearLeftHaz_Wheelie_sub_4bpp_pri19
01547 p1342.01 0 0 0 0 0 0 RearLeftHaz_Wheelie_sub_4bpp_pri19
01547 p1342.01 0 0 0 0 0 0 RearLeftHaz_Wheelie_sub_4bpp_pri19
01547 p1342.01 0 0 0 0 0 0 RearLeftHaz_Wheelie_sub_4bpp_pri19
01547 p1990.07 0 0 0 0 0 0 navcam_1x1_Mast_El_neg60_4_bpp_crit
01547 p1990.07 0 0 0 0 0 0 navcam_1x1_Mast_El_neg60_4_bpp_crit
01547 p2124.03 0 0 0 0 0 0 pancam_cal_targ_L456
01547 p2600.12 0 0 0 0 0 0 pancam_tau
01547 p2600.12 0 0 0 0 0 0 pancam_tau
01547 p2601.03 0 0 0 0 0 0 pancam_tau_L78R48
01547 p2626.03 0 0 0 0 0 0 pancam_sky_radiance_thumbs_L457R247
01547 p2629.04 0 0 0 0 0 0 pancam_horizon_survey_L456
Sunspot
May 31 2008, 09:43 PM
djellison
May 31 2008, 11:16 PM
GREAT stuff - now...onward to Cape Verde!
Doug
dot.dk
May 31 2008, 11:22 PM
Tesheiner
Jun 2 2008, 10:58 AM
Good to see her out of the trap.
Last drive was executed in many steps, like the previous drive attempts. I calculated the slip factor on each of these steps and we can see a sudden decrease at the end of the drive: 93%, 95%, 95%, 85%, 51%.
climber
Jun 2 2008, 11:19 AM
I remember when Oppy get free of Purgatory. In the animation we could see the weels getting more and more efficient.
BTW, I guess Oppy has still the depth record in Mars diging. Not for long I guess, not for long.
Pertinax
Jun 2 2008, 12:53 PM
Please pardon the question: On Oppy's most recent fwd HazCam image, what is the circular brush for on the arm near the upper left of the image? I have not been able to remember it nor have I found any descriptive refrence to it in the little bit of searching I have done thus far this morning.
(And ditto the HURRAY for again being out of the 'trenches'
)
-- Pertinax
jamescanvin
Jun 2 2008, 01:07 PM
That's been asked a number of times before around here.
It's to clean the RAT, in particular the magnets on the RAT I believe.
I can't ever remember it being used however.
Pertinax
Jun 2 2008, 01:18 PM
Thank you James.
I was sure it had been asked, and likely well more than once! Much to my frustration though I couldn't remember the answer! Arrgh.
Anyway, thank you again.
-- Pertinax
BrianL
Jun 2 2008, 04:16 PM
QUOTE (climber @ Jun 2 2008, 05:19 AM)
Oppy has still the depth record in Mars diging. Not for long I guess, not for long.
I don't know. I don't see Phoenix digging anything like this. Especially if ice is just a short distance down.
http://marsrovers.jpl.nasa.gov/gallery/all...IP1314R0M1.HTMLBrian
Ant103
Jun 2 2008, 06:52 PM
Good to see Oppy finaly released of this sandy crap
.
Here is a view front of the rover showing disturbed soil :
Have you seen the boulder ejected by one of the wheel?
Before :
http://qt.exploratorium.edu/mars/opportuni...AHP1990L0M1.JPGAfter :
http://qt.exploratorium.edu/mars/opportuni...ATP1990L0M1.JPGMaybe tilt of the ground have contributed to the rolling of this boulder (I want to say the "rolling stone"
)
And a panorama at the other side :
climber
Jun 2 2008, 08:52 PM
Nice pano, Ant. I don't know why but , it looks different from the one before. May be because I'm more seen too much Northern plain panos
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please
click here.
