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Unmanned Spaceflight.com > Mars & Missions > Past and Future > MER > Spirit
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brellis
thanks so much fredk! One more Q: how do they "freeze" the wheel on the test bed Rover?
Floyd
Just don't power up the motor on one wheel. I think each wheel has a servo motor controlled by a control board that take instructions from the computer--the computer gets its instructions from the rover drivers... rolleyes.gif The six wheels can be commanded independently--so just command only 5 to rotate.

The gear ratio to the motor is so high that it is essentially impossible to drive the motor by torque on the wheel (Though someone here showed pictures that there has been some small rotation after a lot of dragging over rocks and junk). (I don't think there are worm gears or anything that absolutely prevents it from going backwards).

I don't remember any source for these ideas--maybe I adsorbed them from the ether--so Doug or someone with real engineering knowledge--feel free to correct any significant errors.
brellis
Thanks Floyd smile.gif
Astro0
It's been a while since we had any new piccys in the thread (other than the Calypso Pan).
So here's a bunch generated through MMB and some hand stitching.

Forward deck area...
Click to view attachment

Pancam shadow...
Click to view attachment

...and the reflection of a familiar face not seen in a while smile.gif
Click to view attachment

"Hey, turn your head a bit so we can see your pretty face." pancam.gif
HughFromAlice
QUOTE (Astro0 @ Jul 28 2009, 11:09 PM) *
"Hey, turn your head a bit so we can see your pretty face." pancam.gif


Great pics Astro0! But only one mistake - where's the dust..... photoshopped out? Talk about clean..... turn your head a bit so you can look in the mirror!!!! (Studying the nature of this 'dust' would be interesting in its own right).
ElkGroveDan
QUOTE (Astro0 @ Jul 28 2009, 05:39 AM) *
"Hey, turn your head ..." pancam.gif


Paolo needs to examine your WEB for damage. Turn your head and cough.
JayB
nothing really new but wired.com has a nice photo essay on Free Spirit

http://www.wired.com/wiredscience/2009/07/...overmars_rover/
brellis
Great essay, it really helps visualize the predicament occuring so far away. *fingers crossed* - go drivers!
serpens
Image guru Hortonheardawho noted this peculiar item near Spirit. Almost certainly from the Rover but what is it? Could be worth an MI.

Click to view attachment
SpaceListener
Where is the source of the above image?
fredk
Here's the original context image:
http://marsrovers.jpl.nasa.gov/gallery/all...E5P2386L2M1.JPG

It looks to me like the surface has been scraped, revealing a brighter layer (rock surface?) underneath, rather than that the "squiggle" is an object sitting on the surface. It may be that the adjacent rock was moved when the wheel drove by, and scratched the surface.

If you look just below and to the right of the "squiggle", you can see a similar "scrape" feature along the edge of the wheel cut. That feature is also bright in IR and dark in blue, relative to the rest of the ground.

(If you're watching, good catch, Horton!)
craigmcg

Been following the spirit saga somewhat closely, but I haven't seen any mention of what will the plan be if she is declared "stuck." Will the ops team be scaled back, resources moved to Oppy, etc? I realize that it will probably be some time before this would happen...

My take on all the coverage so far is that either they are being very cautious or they really don't think there is much chance of getting unstuck. I've not seen any mention of a scenario that has succeeded in the test bed.
SpaceListener
QUOTE (fredk @ Jul 29 2009, 12:29 PM) *
It looks to me like the surface has been scraped, revealing a brighter layer (rock surface?) underneath, rather than that the "squiggle" is an object sitting on the surface. It may be that the adjacent rock was moved when the wheel drove by, and scratched the surface.

The surface is covered by dust and around of the squiggle made by a near stone has no wheels marks of rover. That makes me to doubt about your hypothesis.
QUOTE
If you look just below and to the right of the "squiggle", you can see a similar "scrape" feature along the edge of the wheel cut. That feature is also bright in IR and dark in blue, relative to the rest of the ground.

The moved stone has no explanation for me since it was dragged leaving a maybe more than 10 cms mark. The drag force for that kind of mark is made from something which is pushed it or also by a strong wind like to many moved stone close to Phoenix landing.

On the other hand, I tried to visualize if by that analysis zone was marked by rover wheel but I was not able to see it.

SpaceListener
QUOTE (craigmcg @ Jul 29 2009, 01:35 PM) *
My take on all the coverage so far is that either they are being very cautious or they really don't think there is much chance of getting unstuck. I've not seen any mention of a scenario that has succeeded in the test bed.

I think that the previous tests are not totally worth since the testbed surface context was fully homogenized. Hence, they want to validate by testing again according to a more realistic surface as it is happening to Spirit in Mars, two right wheels (RF, & RM) on firmer surface and the rest of wheels on a loose sand.
stevesliva
QUOTE (craigmcg @ Jul 29 2009, 02:35 PM) *
My take on all the coverage so far is that either they are being very cautious or they really don't think there is much chance of getting unstuck. I've not seen any mention of a scenario that has succeeded in the test bed.


IIRC, there was a direct quote from one of the team that they expect to get out. They're just being very deliberate. And if you look closely at the photos in the Wired spread above, you'll notice that they were able to move quite a few inches backwards in at least one test. Moving that distance in total homogenous quicksand is pretty encouraging.

There was also an indication that they can reasonably expect to survive winter at the present position with the present power levels, so with regards to what it would do if it's stuck... a lot more of what it's doing now.
centsworth_II
QUOTE (craigmcg @ Jul 29 2009, 01:35 PM) *
Been following the spirit saga somewhat closely, but I haven't seen any mention of what will the plan be if she is declared "stuck...."

John Callas, rover project manager at JPL, was asked about this during the recent Ustream presentation, "Free Spirit." He said if permanently stuck, Spirit would become a stationary lander and could have a useful life of at least a Martian year observing weather and surface changes, and studying the structure and composition of its surroundings in detail.
djellison
We've already got, I think, a little bit of that bright feature in one MI image. I'll try and tie it together tonight. It's very bright.
Astro0
A couple of additional images for fun smile.gif
Click to view attachmentClick to view attachment
djellison
QUOTE (craigmcg @ Jul 29 2009, 07:35 PM) *
My take on all the coverage so far is that either they are being very cautious or they really don't think there is much chance of getting unstuck. I've not seen any mention of a scenario that has succeeded in the test bed.


"We are seeing motion, and it is promising. But from what we see on Earth, we still believe it is going to take a while once we start the extraction process on Mars" - that's Sharon Laubach quoted at the MSNBC Cosmic Log.
fredk
From the latest Free Spirit update, of all places:
QUOTE
Meanwhile, observations from the Mars Climate Sounder instrument on NASA's Mars Reconnaissance Orbiter indicate to scientists that a large regional storm is developing. Right now the dust storm is not near Spirit or its twin, Opportunity, but scientists will continue to monitor it as it develops. Since Mars is still in the dust storm season, it is possible (and perhaps even probable) that the storm will continue to grow over the next few days.
ph34r.gif
MahFL
Whats a "while" 1 month, 1 year ? I wish they could be more specific....they are scientists/enginneers...right ?
JayB
QUOTE (MahFL @ Jul 31 2009, 07:01 AM) *
Whats a "while" 1 month, 1 year ? I wish they could be more specific....they are scientists/enginneers...right ?



Yep...they'll define "a while" 3 months after she's free, once it's been peer reviewed and published laugh.gif
djellison
QUOTE (MahFL @ Jul 31 2009, 03:01 PM) *
they are scientists/enginneers...right ?


So they know better than to cite a specific time frame when they know there are so many variables and unknown unknowns involved
PDP8E
There are some great shots from the NAV camera doing some sunrise work at West Valley.
The shadows of the surrounding area, the rover tracks, and even the sun peeking over Home Plate are quite unusual
Makes me want to climb out of the sleeping bag, stretch my legs, grab a hot cup of coffee off the campfire, and look around at the new day

here is a sample:

http://qt.exploratorium.edu/mars/spirit/na...E5P1987L0M1.JPG


full directory:

http://qt.exploratorium.edu/mars/spirit/navcam/2009-08-03/
Phil Stooke
"Whats a "while" 1 month, 1 year ? I wish they could be more specific....they are scientists/enginneers...right ?"

But not meteorologists. It's like seeing a tropical storm begin in mid-Atlantic and trying to predict its effect on Florida. Can't be done until much closer to landfall.

Phil
MahFL
PD, yes, some are very atmospheric in nature. Like you say, makes you want to go for a walk there.
Ant103
Wow, yes, a very dramatic scenery smile.gif.

I stitched the panorama of this. Very hard to adjust brightness between some frame.

ups
We are getting close to something happening -- I think everyone is starting to feel that.
SteveM
Looking at Damien's recent panorama, I saw some little dents on the top of the antenna and on an adjacent metal part at the right edge of the pan. They may have been there before but the oblique sunlight really made them visible. It looks like my car after it was sitting in a hailstorm.

Any suggestions on what process could be causing dents like this?

Steve M

PS For clarity, here are the dents I'm talking about.
Click to view attachment
djellison
Do you mean the dust on top of the LGA ( the pipe like antenna ) which has been there for years or the crimping around the edge of the HGA (which has been there since it was made)

Not sure what you consider a 'dent'. Can you point to it specifically.
mhoward
Here's another version of the Sol 1984 morning pan. MMB's image-destretching abilities help a little bit here (just a little bit).



QuickTime VR version (2.3 MB)
SteveM
QUOTE (djellison @ Aug 4 2009, 01:57 AM) *
Do you mean the dust on top of the LGA ( the pipe like antenna ) which has been there for years or the crimping around the edge of the HGA (which has been there since it was made)

Not sure what you consider a 'dent'. Can you point to it specifically.


Thanks Doug.

I see about the crimping on the HGA (which I didn't recognize from this perspective).

Click to view attachment

The top of the LGA seems to have at least two depressions (the illumination's from the left as shown by the rocks in the background, so they don't seem to be mounds of dust). Your suggestion that there's dust up there could explain the depressions; it's certainly more plausible than denting. smile.gif

Steve M
PDP8E
Mhoward,

That was a Qtime VR treat!

thanks

maycm
According to New Scientist the plan is to use a combination of all the moves to eventually free Spirit.

I can just hear Captain Picard (or should that be Paolo) instructing 'rotate shield frequencies' laugh.gif

CosmicRocker
Thanks for the link, and the Star Trek metaphor, but I'm a bit disappointed that there was no mention of the "sidewinder" maneuver, previously discussed here. It would offer a continuously changing motive vector which just might be the ticket for this predicament.

Returning to the Star Trek theme, I was picturing Squyres telling Paolo, "Make it so, Number One." cool.gif
briv1016
Now when the article said they plan on moving "forward" do they me relative to the vehicle's orientation or relative to the vehicle's prior motion?
Shaka
At this stage, I'll support anything, as long as it's out!
djellison
QUOTE (SteveM @ Aug 5 2009, 03:22 AM) *
Your suggestion that there's dust up there could explain the depressions; it's certainly more plausible than denting. smile.gif



It's out of focus, remember, and over the last 5 years, you can see the dust arriving, getting blown away etc. With the recent cleaning events and the strong winds inferred - clumping and moving of dust is to be expected. It's well worth hunting for normal pancam images of it to get a better idea.
HughFromAlice
QUOTE (maycm @ Aug 5 2009, 12:21 PM) *
New Scientist the moves to eventually free Spirit


Thanks for the link. I thought the punch line was at the end of the article - ------- "It's going to take us a long time to get out," Callas told New Scientist. "But it's encouraging that the rover in the sandbox is climbing; it has enough capability to fight Earth gravity to get altitude. (my insert: e.g. climb uphill away from the 'sand' trap) We're expecting that on Mars, where there's only three-eighths gravity, that the rover may actually do better."

Better - that's good news.
Astro0
Rover insiders say that if all goes well, there could be some movement attempted after the weekend.
Fingers crossed! smile.gif

Good luck Spirit wheel.gif wheel.gif wheel.gif wheel.gif wheel.gif
BrianL
QUOTE (briv1016 @ Aug 5 2009, 12:09 AM) *
Now when the article said they plan on moving "forward" do they me relative to the vehicle's orientation or relative to the vehicle's prior motion?


The preceding statements give some context.

"The region we were safely over before could be a challenge now," Callas says. "It's like skating on thin ice."
So instead of backing up, scientists plan to tell Spirit to push forward.

I interpret that to mean they will be continuing in the direction of Von Braun and Goddard.
BrianL
QUOTE (mhoward @ Aug 4 2009, 02:06 PM) *
QuickTime VR version (2.3 MB)


Yow, could have warned us about the sun, Mike. I was practically blinded looking up toward Home Plate. biggrin.gif
briv1016
QUOTE (BrianL @ Aug 5 2009, 08:43 AM) *
The preceding statements give some context.

"The region we were safely over before could be a challenge now," Callas says. "It's like skating on thin ice."
So instead of backing up, scientists plan to tell Spirit to push forward.

I interpret that to mean they will be continuing in the direction of Von Braun and Goddard.



So in the best case scenario were stuck between a sand trap and uncharted territory. This should be interesting. rolleyes.gif
djellison
QUOTE (briv1016 @ Aug 5 2009, 08:56 PM) *
uncharted territory.


The only way to avoid that would be a 5.5 year track back to the lander smile.gif
briv1016
laugh.gif In all seriousness, do we have any estimates on how far forward (in meters) this trap extends?

Edit: Scratch that, if we could determine that we would never have gotten in this scenario in the first place.
CosmicRocker
QUOTE (djellison @ Aug 5 2009, 04:12 PM) *
The only way to avoid that would be a 5.5 year track back to the lander smile.gif

I think that is a good point. These rovers were designed to explore uncharted territory.

QUOTE (briv1016 @ Aug 5 2009, 04:31 PM) *
laugh.gif In all seriousness, do we have any estimates on how far forward (in meters) this trap extends?

Now that we have fallen into it, I think we can see it's boundaries. It doesn't appear to be very far to the other side of the pool.
climber
QUOTE (CosmicRocker @ Aug 6 2009, 07:31 AM) *
It doesn't appear to be very far to the other side of the pool.

Anyway, I wish Spirit could be renamed "Michael Phelps".
CosmicRocker
At this point I will be very happy if Spirit is able to dog-paddle to the shallow end.
nprev
Frankly I'm quite confident that it's a matter of when, not if. TeeBee has apparently demonstrated progress, and the real discovery was that there wasn't a simple pick-a-single-vector/translation maneuver solution.

It's a safe bet as well that Paolo, Sharon & the team now understand the MER's motive capabilities & characteristics far better than ever, and that's knowledge that will pay off big time for a LONG time even after Spirit is freed.

My only concern at this point is that somebody besides them gets stuck with dismantling the sandbox after it's over; they all need a few beers & a few days off! smile.gif
briv1016
QUOTE (nprev @ Aug 7 2009, 02:19 AM) *
My only concern at this point is that somebody besides them gets stuck with dismantling the sandbox after it's over; they all need a few beers & a few days off! smile.gif


BIG vacuum cleaner. cool.gif
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