TEGA - Round 2 Options

[Floyd]

I think we should all switch to apparent solar time (not even mean solar time). Standard time was a bad invention of the railroads.

-Floyd

[climber]

even Malheur County is split into two time zones.

In case you don't know, have a look of what Malheur means in French...

[djellison]

As far as heating of the scoop goes, does anyone know if there are heaters in the scoop joints or rasp mechanism?

Yes - loads of them. All over the arm to get it to work in the cold -80 temps.

http://trs-new.jpl.nasa.gov/dspace/handle/2014/39718

Doug

[jmknapp]

As far as heating of the scoop goes, does anyone know if there are heaters in the scoop joints or rasp mechanism? If so, could significant heat conduct through the scoop walls to the back of the scoop where the rasp shavings go?

Trying to understand how the sample is collected, here's a diagram for your consideration :



I think the rasp is designed to collect soil and deliver it by the red-arrow route to the scoop proper (by a series of moves to get it around the baffles). Then, as the recent press reports state, any remaining "tailings" are scraped off the surface by the main blade (blue arrow). The recent image shows soil adhering to the back of the scoop as indicated. Is that right?

If so, I wonder what route the soil in this case took primarily. Did it get around the baffles only to stick to the back of the scoop? Or did it primarily come from the tailings via the main blade?

Does the operation of the rasp motor heat up the surrounding structure appreciably? The rasp motor is right behind where the sample ended up, so maybe that wall of the scoop gets somewhat warm and the soil later froze to it when the heat dissipated?

[NotLurkingAnymor...]

Presumably an unknown amount of material did make it into this oven. Can this oven be used again?

[TheChemist]

The oven will be used again for a second attempt today, if I remember well.
The only problem I see is that if an unknown quantity of sample got inside the oven the first time, maybe the water content calculated from the second attempt will be slightly underestimated.

[BrianL]

There's stuff sticking to the screen on the Sol 62 TEGA image. Want news...

[jamescanvin]

You mean there WAS material stuck to the screen, it has disappeared an in images taken an hour later! Fallen in or sublimed away, can't wait to find out. Very exciting!

[djellison]

Want news...

And I want a pony - but sometimes no matter how much we ask, we just have to wait and see.

[jmknapp]

There's stuff sticking to the screen on the Sol 62 TEGA image. Want news...

Interesting that this image, taken after the image showing stuff on the screen (08:06 vs 07:54), would seem to indicate that at least some soil still stuck to the scoop, post-dump:

http://phoenix.lpl.arizona.edu/images.php?...417&cID=183

EDIT: it does give the impression though that parts of the mass broke loose:

[ElkGroveDan]

The icy soil in the Mars environs, looks and seems to behave like this children's toy called "Floam" here on Earth at STP. Maybe they should try that in their test bed to see how best to manipulate the samples on Mars.

[Juramike]

Maybe they should try that in their test bed to see how best to manipulate the samples on Mars.

The recipe can be tweaked to make it stiffer or more fluid. It looks like a fun project to try at home:

How to make Floam

-Mike

[brellis]

Sounds like you can make a nice igloo outta this stuff, as long as you do it quick-like!

[NotLurkingAnymor...]

Just a few more thoughts on the state of oven 0.

As this is Mars and prof. Murphy's laws prevail (Oppy being the exception), This oven was one grain short of a full-signal.
Prof. Murphy's second law clearly states the water content of this sample, after sitting for a Sol+ in TEGA's warm belly.

All I'm thinking is that subsequent attempts to make a sample delivery to oven 0 can only be a practise for the next TEGA oven (3?).
Without knowing the many unknowns of the state of oven 0, any subsequent results are somewhat open to question.

Once more into the breach, dear friends.

[01101001]

Failed again. Not enough delivered to TEGA.

JPL Phoenix Mission News: NASA's Phoenix Mars Lander Working With Sticky Soil (July 28)

The team tried two methods over the weekend to pick up and deliver a sample of icy soil to a laboratory oven of the Thermal and Evolved-Gas Analyzer (TEGA). In both cases, most of the sample stuck inside the lander's inverted scoop. Images returned early Monday showed a small amount of soil reached the screened opening, but other data indicated that not enough had been funneled into the oven for beginning an analysis of the composition.
[...]
[Principal Investigator Peter] Smith said, "While we continue with determining the best way to get an icy sample, we intend to proceed with analyzing dry samples that we already know how to deliver. We are going to move forward with a dry soil sample."