Spirit - Still Alive - volume 2 - Page 3

sol 2052 ( Oct 11, 2009 ) MI pan of soil:

Looks like another "test hole" soil study will be done in this area. I think I have located the area but will wait until another pancam full filter sequence is done.

Yes,,just above the rock in the center,,what in
the world can make this surface act like this?
Something going on underneath,that's for sure.

Almost as if we are above a rift and some sort
of gas moves up thru it? Thus disturbing the
(?)soil?
Joe in Texas

sol 2061 ( Oct 20, 2009 ) animation of underside of rover:

It looks like the "pointy rock" is touching the bottom.

This is the problem I am sure Spirit over the time it has been stuck at Troy will have sunk a few CM's. I am not sure what sort of wires/pipes etc. are on the underbelly but certainly NASA know and are planniing a sideways manouver to escape and cannot afford any wheel slippage and dig in even more. I fear the worst for Spirit and any driver that gets her out will deserve a big pat on the back.

Perhaps one reason they are taking their time preparing for the escape attempt is that every day takes us closer to opposition, in January 2010, when Mars and Earth are at the closest point in their orbits. This would allow something closer to realtime commanding for the escape attempt. Not sure if that matters or not.

As Serpens pointed out earlier, it is not a simple pinnacle but a wedge shaped ridge .
I can't see how they can gain enough traction to get off it.

Does anyone know how close the rock contact is to the center of mass of the rover?

Why is Spirit not going in the direction of fall, then recover with redirected wheels to coast downhill?
Just a thought.

yt
dx

How strong is the robotic arm? Can Spirit use it to help lift, bend or push itself out of the soft sand?

sol 2072 ( Nov 1, 2009 ) hazcam 3D view before the extraction attempt:

with links to a navcam panorama looking north and a final look under the lander.

Good luck Spirit.

The old gal is hobbled, forgetful, weak and arthritic - but she will try one final time to free herself and journey to the promised land.

Earlier in this thread we worked out the arm is not powerful enough to lift the Rover it literally can only produce a few pounds of downforce.

From The Martian lives of Spirit and Opportunity:

Several people have questions about using the IDD [Instrument Deployment Device, or robotic arm] to help get Spirit out. The IDD is very low in mass and was only designed to exert the forces needed to firmly place instruments on science targets.

That means moving it around barely shifts the rover's center of gravity and attitude. The arm can only exert at most about 20 pounds of pressure, which is only 13 percent of what would be needed to lift the rover's mass on Mars. With that level of force we again could only minimally affect the rover's attitude, and would not be able to move rocks of any significant size. And if we tried, we would definitely risk damaging the instruments or the IDD itself. If all else fails, we may give one of these strategies a try and hope that the small difference is enough, but these are all very risky, and so far down our list of options.

sol 1889-2072 ( Apr 27-Nov 1, 2009 ) animation of buried left rear wheel:

If I understand this animation correctly the rear left wheel is completely buried.

Spirit has now been trapped more than 184 sols - 2 nominal missions - and has been a "lander" longer than Phoenix survived!

Does anyone have a view of the left rear wheel in the test bed? The only images I can find do not show the wheels as deeply buried as the Mars images seem to indicate.

See, for example, this one.

sol 2078 ( Nov 7, 2009 ) animation of the first attempt of "The Great Escape" from Troy:

It has begun.

Good luck with Spirit - one of the ultimate Martians explorers was droved towards Columbia hills, - revealed the mystery Ultreya feature among many many other features. Oh, just a little nostalgic.

sol 2072-2078 rear hazcam R0 animation:

Confirms that the net result of the move was that the left rear wheel ( on the right ) sank a little deeper.

sol 2076, 2078, 2079 front L0 hascam animation:

Looks like the IDD is being used to shift the rover's center of gravity forward. Perhaps to provide more traction to the front wheels that are less buried than the rear wheels?

Nice one Hort you should have your own show! Wow I did not know the rear left was completely buried it will take some torque from the remaining wheels to pull free.

dx suggested using the IDD to alter centre of gravity that might be a good call.

Fantastic animations.

Come on Spirit you can do it!

> ... left rear wheel ... sank a little deeper.

At least this suggests the rover is not grounded on the wedge-shaped rock.

Live briefing this Thursday on Spirit's progress details here:

http://twitter.com/MarsRovers