MECA (microscope) Images Options

[elakdawalla]

See my update from today -- they hope to finish characterization of the Atomic Force Microscope tosol, so we should shortly begin to see it being used on samples already tagged in the OM.

--Emily

[Phil Stooke]

Can we identify the Vestry location in an image?

Phil

[TheChemist]

The first AFM image of a test material was obtained.
So at least we know the AFM works as planned.

http://www.jpl.nasa.gov/news/phoenix/images.php?fileID=14644

[remcook]

For those who haven't seen it yet, there's a new installment in Tom Pike's BBC blog:

http://news.bbc.co.uk/1/hi/sci/tech/7408033.stm

Interesting bit about the AFM:
"The particles, though, are much more difficult to image. They tend to be pushed about by the sharp tip of the AFM, frustrating our attempts. On Earth, we'd be able to turn a few knobs to minimise the forces between the tip and the particle.

For Phoenix, each "tweak" of the computer code takes hours to prepare and the results from Mars aren't known until the next sol. We also have to book ahead to be able to run our microscopes on Phoenix.

What takes just a few minutes to run on the testbed in our laboratory in Tucson takes several sols to complete on Mars. A good deal of patience is a requirement for any member of the science team. "

[jmknapp]

"The particles, though, are much more difficult to image. They tend to be pushed about by the sharp tip of the AFM, frustrating our attempts. On Earth, we'd be able to turn a few knobs to minimise the forces between the tip and the particle.

Roadblocks on all fronts, it seems.

In the BBC blog, I wonder what the point is of making soil/ice mixtures in one's kitchen--not exactly Mars conditions.

[MahFL]

I wonder if they anticipted this problem. In laymans terms, its not working.

[Juramike]

In the BBC blog, I wonder what the point is of making soil/ice mixtures in one's kitchen--not exactly Mars conditions.

I'd guess that they are taking the soil/ice mixtures and then putting them under partial vacuum (or what passes for atmospheric pressure on Mars) and watching stuff sublime.

[BTW, we do this all the time with water-soluble compounds. Dissolve in water, freeze, then put under a high vacuum to sublime out the water. The dissolved stuff slowly precipitates out in the frozen matrix and becomes hyperfluffy. The lyophilization process makes it real easy to manipulate miniscule amounts of material (sub-milligram quanities) with a laboratory spatula.]

-Mike

[Aussie]

I wonder if they anticipted this problem. In laymans terms, its not working.

They did. The substrate etching/holes were specifically designed to bound trapped particle size and minimise the movement of those particles. Given time they will probably be able to adjust the focus to reflect the sample, but the tip is delicate and vulnerable to the effects of rough particles. Overall the inclusion of the AFM seems somewhat of a gamble and possibly this is why there is an AFM shaped hole in the Mission Success Criteria.

[nprev]

Have to ask why it's even considered part of the mission success criteria, then. Nobody's ever flown an AFM before, AFAIK; if so, this is a pathfinder effort. Deploying the thing and getting a read on the control target is a success, as far as I'm concerned. Learning about the effects of environmental variables is one reason it's there in the first place.

[jamescanvin]

Have to ask why it's even considered part of the mission success criteria, then.

According to Mark in the mission success thread use of the AFM is not a mission success criteria. The OM alone is enough to satisfy "It shall also analyze 3 additional samples in its microscopy station."

[Aussie]

Poor use of language. By 'an AFM shaped hole in the Mission Success Criteria' I meant that the AFM was not included in the criteria. I agree with Mark.

[CosmicRocker]

For those who haven't seen it yet, there's a new installment in Tom Pike's BBC blog:

http://news.bbc.co.uk/1/hi/sci/tech/7408033.stm

Interesting bit about the AFM:
"The particles, though, are much more difficult to image. They tend to be pushed about by the sharp tip of the AFM, frustrating our attempts. On Earth, we'd be able to turn a few knobs to minimise the forces between the tip and the particle.

For Phoenix, each "tweak" of the computer code takes hours to prepare and the results from Mars aren't known until the next sol. We also have to book ahead to be able to run our microscopes on Phoenix.

What takes just a few minutes to run on the testbed in our laboratory in Tucson takes several sols to complete on Mars. A good deal of patience is a requirement for any member of the science team. "

I could hardly believe it when I first learned that Phoenix carried an AFM experiment. I don't know a lot about these devices, but sending one to Mars certainly seems like a bold move to me.

I couldn't help but wonder though, about the "computer code tweaking/uplinking/downlinking" strategy. Might it not be easier to simply move the tip to another potentially trapped particle, and try to probe it with the default parameters? I suspect my ignorance of interplanetary AFM operations prevents me from seeing the errors in my suggestion, but I couldn't help but speak my mind.

[teck]

Anyone wants to identify these tiny grains from the OM?
This looks like a nice catch.

[jmknapp]

Anyone wants to identify these tiny grains from the OM?

J-j-jumping Juniper! A golden egg! T-twenty-four karat dilithium crystals! We're rich!

[djellison]

The colours are really hard to pull out - looks cool though. This is a mosaic of three obs that cover the whole substrate.

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