Extricating Spirit, Digging out from Troy Options

[fredk]

From Maxwell:

Next drive should tell us a lot: whether we can cut new tracks, or just bog down at end of rut.

As I wrote yesterday, we were already cutting new tracks on 2154. And that has continued on 2156: we've made considerable progress cutting through the crust, as you can see in this enhanced view:

And, as others have mentioned, that LR wheel has popped way up!

[Hungry4info]

Looks like it might have climbed up on that rock.
(is that the potato?)

[alan]

The potato sized rock that was ahead of the LR on sol 2154. In fredk's animation it appears to going under the wheel.

Potato is in reference to a rock that got into Spirit's wheel well back on sol 339

http://marsrovers.jpl.nasa.gov/mission/sta...004.html#sol333
http://marsrovers.jpl.nasa.gov/gallery/all...2P1395R0M1.HTML

[Hungry4info]

Ah, alright. Thanks. =)
Getting very optimistic about the extraction.

[fredk]

RHaz for Sol2154 (Sunday) shows Spirit pushing a rock along - bottom centre-left... If they drove again on 2156 and they still made progress then it's probably not an issue.

Great catch, Astro! That rock was sticking up particularly high, so not too surprizing it was pushed. And it moves a bit more on 2156, but doesn't seem to be hampering the rover.

And where's that rock that we all were worried about?

It's coming! But what happened to the rock Astro spotted gives us a clue that almost certainly other rocks are being moved around under the belly. So Belly Rock in particular may be pushed backwards (southwards) as we drive. If we get clear of Troy, I'll bet it'll be really hard to identify the rocks in before and after images!

[Julius]

sol 2156 would be today?

[djellison]

http://www.giss.nasa.gov/tools/mars24/merclock.html

Yes.

[MarkG]

http://www.giss.nasa.gov/tools/mars24/merclock.html

Yes.

now, THAT is a handy little gadget... Thanks!


Now here is a question -- if Spirit's arm was extended more towards the right, it would make a small, but maybe helpful, difference in the center of gravity towards the uphill side... Has this been considered?

[alan]

Conference has started

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

[Hungry4info]

"It's driving days are likely over."

It looks like they're going to tilt the rover into the sand trap.

160 watt hours are estimated to be needed to maintain activities (contacting each day). Otherwise, hibernation (fault mode).

Electronics can handle being below -50° C when not operating, -40° C when operating, expected to get to -45° C in winter. It is expected Spirit will survive, but not guaranteed.

Remaining activities: get LR up to improve tilt (eastward tilt is preferred). Significant improvement on northerly tilt of 1 - 2° on last drive. Try to tilt the rover north-ward and/or east-ward.

Not as much as an emphasis on driving with only 4 working wheels, so stationary science will be emphasized. Ideas: Spirit being tracked to constrain Mars' spin axis wobble rate, giving insight into the planet's interior. They think they can do this in six months. Additionally, a stationary mission will enable them to watch how features there change due to wind, as well as watching how soil is stirred by wind as seen through the microscope. They'll be given an opportunity to better characterize the soil. With the limited mobility, they maybe can move around to reposition the rover to enable other science experiments.

[fredk]

Backwards drives will continue in the near term.

Curious "news" item.

[hendric]

Possible science come spring

Radio science to determine axial wobbles - Determine molten or solid core
Atmosphere and surface changes - Look at macroscopic and microscopic changes on the surface
Comprehensive soil characterization - this is a really strange set of soil. Not like normal Martian soil. Extremely rich in sulfate salts. Salts initially formed by fumaroles. After billions of years, other water processes caused salts to move around. Soluble salts had moved around. Moderately good picture of soil structure. Lots of time will allow much greater characterization. Expect to use wheels in spring to slightly reposition rover to reach new soil.

Bottom line: Not giving up on Spirit

[tacitus]

You've got to hand it to Steve Squyres. I don't know anyone else who could sell a major reduction in Spirit's capabilities as a ground-breaking, exciting opportunity quite so effectively.

[hendric]

Here's the official press release

http://www.jpl.nasa.gov/news/news.cfm?release=2010-030

More info

http://www.nasa.gov/mission_pages/mer/news...el20100126.html

[fredk]

I'm hoping someone will ask if extraction attempts might continue in the spring. It sounded like the answer was "no", but it wasn't entirely clear. If it is "no", then exactly why considering the recent progress?

Edit: Emily asked! Squyres McCuistion said problem was basically that we have a four wheeled rover.