Extricating Spirit, Digging out from Troy Options

[Robert S]

Holding my thumbs!!! This is so thrilling. I am trying not to bee too optimistic yet, but it's hard not to be!

I think maybe the greatest concern is if she can survive the Winter. Not much power left.

[climber]

I wrote "exactly here". I would only expect short moves trying to improve the rover's attitude.

If I've not lost my orientation, left side is globaly down and right side is globaly up, so, tilt is to the West instead of North which is not ideal.
So, can we say, moving a bit more so forward weels will stay down (except RF), and rear weels will rise a bit up, will be the best we can do with the power still left for moving?
I feel a few more degree could make the difference between making it throught winter or not.
Not sure to be correct in the orientation so, correct me if I'm wrong.

[Tesheiner]

Nothing to correct, I would say.
Most of the tilt is west, yes, but there's a slight north component on that; more then at the beggining of the extrication process, and that's a good thing.

[Hungry4info]

climber, as far as I know, the geometry you describe was accurate, but with the rover having turned quite a bit, I figure much of the tilt is West or North-West.

[marsophile]

Even with a northerly component to the tilt, a westerly component will reduce the effective area presented to the noontime sun. It will also reduce morning solar power but increase afternoon power. Taking all these into account, how much of a hit is westerly tilt? Is it worth trying hard to reduce westerly tilt by rotating in a way that gets the left side wheels out of the crater? Or does the northerly tilt component predominate and the westerly tilt is essentially irrelevant?

[Ant103]

I've made a short sequence showin all the right FHC from Sol 2025 to 2154. I think it's a good time to post video like this .

http://www.youtube.com/watch?v=fktBKtq3zL4

[Julius]

Curious to know what the Mars Rover team think now about Spirits chances of roving again!

[briv1016]

On NASA's main page,

"Media Teleconference on the Status of Mars Rover Spirit, Tues. Jan. 26, 1:00 p.m. EST on NASA News Audio."

Link: http://www.nasa.gov/news/media/newsaudio/index.html

[Guest_Sunspot_*]

Hmmm I suppose it could go either way news wise - they think the might get out or maybe suspending attempts to get to concentrate on getting into a better position to survive winter.

[fredk]

Based on the spaceflight now article, I'd think they will announce that they've switched from extrication drives to tilt-improving drives. From that article:

it is likely virtually all future maneuvers will be devoted to further improving the attitude of Spirit's top solar array relative to the Sun.

Another quote from that article that surprized me is:

driving backwards... provided minimal progress, except for one very significant benefit -- the back wheels tended to climb, elevating the solar array deck more directly north.

I can't see how anyone could call several cms (vs the previous mms) "minimal". There's certainly been progress in terms of distance, but I think what the article meant to say is that most of the wheels are still embedded. But the improvement in tilt suggests they may continue with similar backwards drives.

Another interesting quote about the tilt-improving drives to come:

"The other thing we might try once in optimum position is activate the right front wheel just to steer it back and forth to literally try and grind it into the ground. That will tend to dip the right front side of Spirit and also [point] the deck more toward the north," Callas tells Spaceflight Now.

[fredk]

It's truly amazing how much the team has learned about operating these rovers at low power.

Last winter solstice... power at 230 watt-hours... last week’s update... power at 211 watt-hours

I don't think the fact they're still driving at 211 Whrs is due to anything they've learnt about operating at low power. Remember that it's much colder at winter solstice, so they need considerably more power to run the heaters than they do now. That's why they couldn't drive with 230 Whrs last winter, while they are driving now at 211.

[fredk]

Fredk, isn't the LR in better postion now as compared when she get embeded? I mean nearly on top instead of inside the crust.

Better, but still mostly below the crust it looks to me. But the RR seems to have lifted mostly above ground.

[mhoward]

Another quote from that article that surprized me is:I can't see how anyone could call several cms (vs the previous mms) "minimal".

Yeah; I think that should be a question for the teleconference. I don't think a lot of people are going to understand that unless we see another drive, since she's been doing pretty well 'till now retracing her steps.

[climber]

"The other thing we might try once in optimum position is activate the right front wheel just to steer it back and forth to literally try and grind it into the ground".
I thought about this without reading Spaceflightnow but was too shy to post it here! So now, we have to find a way to lift up left rear knowing we CANNOT use th IDD to put a rock under THAT weel

[Julius]

So if I understand correctly,they seem to be pessimistic about ever getting Spirit out of the sand trap.