TEGA - Round 2 Options

[djellison]

I challenge you not to look at this and make a ping/spring/boing happy sort of a noise.

http://phoenix.lpl.arizona.edu/images/gallery/lg_14223.jpg

[rob66]

ping! spring! boing !

A beautiful sight

[Stu]

Hmm, my noise was kind of a combination of a long, drawn out sighing "Phew!" and a fist-clenched celebratory "Yes!! Get IN there!!!"

[nprev]

Oh, right on!!! What a welcome sight. Get it in there, baby, get it done!

[Tesheiner]

"Phew" is the best word, I would say. Now it's time to put some ice in there.

<log off> <looking for a cold drink in the freeze>

[Reckless]

Sproing indeed

[dmg]

Great news on the door. Here's hoping that all goes well on the sample delivery. I for one would not like to be the person to enter the "vibrate on" command, then have everyone waiting to see if the short circuit acts up and kills the whole vibrator circuit or the whole instrument.

[djellison]

Left Eye R/B fudged colour. Right Eye Diopter IR/B fudged colour, and a colour anaglyph of the two.

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[centsworth_II]

Question from old TEGA thread:

.....So should they not have a D:H and C13:C12 measurement already?

My (non expert) impression is that since the first sample was devoid of volatiles -- CO2 and H2O -- the signals would not be large enough to easily check ratios.

[Shaka]

At the sound of your voice Heaven opens its portals to me! Can I help but rejoice...

[climber]

Left Eye R/B fudged colour. Right Eye Diopter IR/B fudged colour, and a colour anaglyph of the two.

I was looking for the anaglyph to be very very very sure. I can confirm now : it's open!
Regarding your challenge, my note was... 0

[belleraphon1]

I just caught the news from Emily's blog.....

What a beautiful sight ...... !!!!!!!!

GO PHOENIX... let's sniff some ice!!!!!!!!

It is SO cool to watch these missions progress.....

Craig

[CosmicRocker]

I was looking for the anaglyph to be very very very sure. I can confirm now : it's open! ...

Hilarious, climber! That's a good one.

Way to go, Phoenix! It's a beautiful sight, indeed.

[jmknapp]

My (non expert) impression is that since the first sample was devoid of volatiles -- CO2 and H2O -- the signals would not be large enough to easily check ratios.

Maybe so--here's hoping the recent success with the doors will widen TEGA's perception.

The sound that comes to my mind, courtesy The Doors, is a combination of "break on through to the other side" and "come on baby light my fire"" MP3.

"If the doors of perception were cleansed every thing would appear to man as it is, infinite. For man has closed himself up, till he sees all things through narrow chinks of his cavern." -- William Blake

[Solar Fan]

Yea!

It looks like they've successfully uttered the command "Open Sesame".

[Cargo Cult]

It looks like they've successfully uttered the command "Open Sesame".

Previously, they'd been asking HAL to open the pod-bay doors - with predictably little success...

(Could this suggest that this whole side of doors may be operational? If so, second hooray!)

[Ken McLean]

(Could this suggest that this whole side of doors may be operational? If so, second hooray!)

IIRC, I believe the ovens on the ends were expected to be more likely to open fully because of the way the hinge mechanisms work. If that's true then it's more likely to suggest the other three end ovens will open too.

[centsworth_II]

...it's more likely to suggest the other three end ovens will open too.

You mean the other two. The first oven opened was an end oven and one of its doors only partially opened, so it looks like we won't know exactly how each door will open until it's opened.

[BrianL]

My momma always said, "TEGA is like a box of chocolates. You never know what you're gonna get."

[Skyrunner]

My momma always said, "TEGA is like a box of chocolates. You never know what you're gonna get."

Now lets hope she finds some shrimp

Could this whole side be opening fully instead of 'only' doors 0 and 3? They think they know which part is the problem but why could that part on this side of TEGA not be manufactured according to specs? I surely hope doors 1 and 2 work as well. Until we try there is no way of knowing. I guess they are first using the end ovens and perhaps try the other onces after that anyway.

[TheChemist]

Apologies, the wait is too long

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[Skyrunner]

Wow, thanks to Emily's Blog we now know more.

The part "not manufactured to a precise enough specification" is the "rail at the bottom". It tends to binds some doors while allowing others to open fine. While that sounds a bit sketchy to me it fuelers my hope that the other side of TEGA will be fine.

More from her blog:

Finally, Leslie cleared up something I've apparently been confused about for a while. The reason they're pressing toward getting an ice-rich sample for TEGA is because of concern about a possible short. This short is a "high-side" short that could affect the whole instrument. It is not the same as the short that affected oven 4; that one is "cleared," it can't possibly affect the operation of TEGA in the future.

So now we know this is another short. Not good news to hear, but on the positive side according to what Leslie Tamppari told Emily the team looking for a possible sol 60 rasp & deliver. The long wait is finally over, we just have to sit out this weekend.

Thanks Emily for that update!

[Deimos]

So now we know this is another short.

No. We don't. What Emily reported is what has been discussed previously--the team is worried about a "possible" future short that could threaten all ovens. There is something unknown that caused one short (in TA 4). There are types of shorts that are local to the oven, like that one. As Emily said, there are high side shorts that affect the entire instrument. There is "no way to assess the probability of another short circuit" occurring, so prudence dictates knocking off the highest priority samples first (http://phoenix.lpl.arizona.edu/07_02_pr.php). Once there is another short, it may simply be too late to be prudent.

[Skyrunner]

No. We don't. What Emily reported is what has been discussed previously--the team is worried about a "possible" future short that could threaten all ovens.

Misread that. I thought 'possible' meant they were note sure there is one as opposed to some new short occurring.

[jmjawors]

This does not clear up anything for me. Then again, I did not personally design nor do I operate the instrument so nothing is likely to make sense to me. Just so long as the teams proceed cautiously, which they are, and do their absolute best to get some ice into that oven.

Have to admit though, those open doors sure were a beautiful sight.

[akuo]

Looks like they are finally going for it:

Scientists and engineers on the mission Friday prepared plans to send Phoenix later in the day that would command the robotic arm to rasp the hard soil in the trench informally named "Snow White," collect the shavings and deliver them to an oven for analysis.

It would be interesting to know more about the plan. Will the oven close immediately when its sensors confirm enough material has entered? If not, how will sublimation be avoided?

[bcory]

"NASA has tentatively scheduled a "mid-course" status report on the Phoenix mission July 31, when results of the latest TEGA run may be announced and new images released. The Phoenix team has asked for an extension of the nominal 92-sol (92 Earth-day) mission, and the outcome of that request may be revealed as well."

more:

http://www.aviationweek.com/aw/generic/sto...EXCITE07258.xml

[Aussie]

I have always been a little in awe of the expertise of the MER and Phoenix teams in trouble shooting and fault rectification at such a huge distance. But for Phoenix, to my mind they have lost the high ground with respect to design and QA and should be indulging in some navel gazing.

First the rail not manufactured to specification jeopardising a proportion of the TEGA capability. OK stuff happens and QA tests get missed, but surely not with an interplanetary lander.

Secondly, a short for oven 4 that is now '"cleared," it can't possibly affect the operation of TEGA in the future'. The cynic in me equates that to a fuse blowing. It can only happen once. But what was the inherent vulnerability that caused it in the first place?

And now a revelation that they have assessed the possibility of another short related failure mode that could have the effect of taking out the entire capability. Possibly the same cause and effect as the oven 4 short. We can only hope the probability of occurrence is low and the ice sample will be successfully tested.

Compliments to the team for identifying the possible failure mode. But that does beg the question as to why this wasn't identified before the mission. Easy to be wise in retrospect, but there does seem to have been a breakdown in their processes.

[01101001]

Sol 60 Raw Images

This looks like post-delivery, 0749 local time. There's a little soil on the adjacent TEGA door.

[fredk]

They certainly got some serious rasping done:
http://phoenix.lpl.arizona.edu/images/gallery/lg_16036.jpg

[jamescanvin]

Here is a before and after gif.

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[Juramike]

They certainly got some serious rasping done:
http://phoenix.lpl.arizona.edu/images/gallery/lg_16036.jpg

Awesome! All that's missing is this. (4 MB, but worth it )

[imipak]

Is it just me, or did they completely miss the oven? There's no obvious sign of sample on the mesh screen, just on the adjacent closed doors.

[ugordan]

I don't think they missed it. There's some material visible on the bottom edge of the mesh as well. The thing is this was nowhere near as much material as the first TEGA delivery so I'm not completely surprised nothing is seen on the mesh. Not completely, but still somewhat surprised not a single particle was stuck at the mesh...

[Reckless]

Looking at the early and late post dump shots htere doesn't seem to be much subliming although it is hard to see as the lighting is different between the 0740ish shot and the 1300ish shot

[01101001]

I venture they got an oven-full signal. Maybe.

There is a TEGA post-delivery image that shows soil on the adjacent door, at 0749:
http://phoenix.lpl.arizona.edu/images.php?...019&cID=179

There is an image of soil remaining in the scoop, at 0755, after the above:
http://phoenix.lpl.arizona.edu/images.php?...109&cID=179

I think it's likely that the programmed sequence was to sprinkle until oven-full was detected. That would leave some soil in the scoop. (But, I suppose it's possible that they sprinkled, imaged, sprinkled, imaged without regard to stopping upon oven-full, and that might lead to the same pictures.)

[centsworth_II]

There's no obvious sign of sample on the mesh screen, just on the adjacent closed doors.

Could be a good sign. The sample went straight through the mesh?

[imipak]

I take it back - there are traces along the lower part of the right-hand door's hinge line, but much clearer dustings on the bottom part of the left-hand door - they're only clear in the RAC images I think.

[Shaka]

Still... I would welcome a confirmation of "oven full" from one of our members-in-the-know.
Howzaboutit, guys? Can I open this champagne?

[BrianL]

Yeah, what's the scoop?

Sorry, couldn't resist...

[akuo]

Not enough material in the oven :-(
http://phoenix.lpl.arizona.edu/07_26_pr.php

[TheChemist]

Well, there is also some good news in there :

The TEGA activities did not cause any short circuits with the equipment.

[dvandorn]

Not enough material in the oven :-(
http://phoenix.lpl.arizona.edu/07_26_pr.php

I wonder if it sublimated between rasp/scoop and drop, or if they just didn't get enough out of the rasping?

-the other Doug

[elakdawalla]

Neither -- "much of the soil remained lodged in the robotic arm's scoop after the attempt to deliver the sample to the TEGA. "

See http://planetary.s3.amazonaws.com/data/pho...9_16B80MDM1.jpg, which was taken at 07:55, which was after the dumping (which happened some time between 07:33 and 07:49).

--Emily

[akuo]

As the press release says "the robotic arm collected a more than adequate amount of icy soil", but most of it stuck to the back of the scoop.

Sounds like a pretty easy problem to fix, but then this is Mars.

[Stu]

Mars has never given up any of its secrets without a fight. Looks like this time is no different.

Got to feel sorry for all the TEGA team; they're obviously working unbelievably hard on this, and Mars just keeps laughing and kicking dirt in their faces. They must be feeling a combination of frustrated/angry/rotten right now.

If any of you are reading this, keep going guys, we're behind you and thinking of you.

[slinted]

Here's an RAC image of the sample before the sprinkle/dump, for comparison:

RGB from red image acquired at 07:29 and blue taken at 07:30

[ArizonaWildcat]

Mars has never given up any of its secrets without a fight. Looks like this time is no different.

Got to feel sorry for all the TEGA team; they're obviously working unbelievably hard on this, and Mars just keeps laughing and kicking dirt in their faces. They must be feeling a combination of frustrated/angry/rotten right now.

If any of you are reading this, keep going guys, we're behind you and thinking of you.

We are reading. Thanks for your kind words.

[Shaka]

I can't stand it.

[belleraphon1]

Nothing comes easy....

Trying to operate a delicate sample delivery remotely... frankly I am amazed at the progress made so far....
All you folks on the Phoenix team have my utmost admiration.

Wondering if the sample material cold welded to the scoop due to the early morning temps? I look at that instrument deck
and cannot imagine how cold all the outer surfaces must be....

Craig

[PDP8E]

1) hold the scoop so that material should fall out.
2) take dump image
2) turn on the rasp (BBBBRRRATTTTTT!!)
3) take post dump image

cheers

[jmjawors]

There is a reason they are not going about it in such a straightforward fashion, PDP8E. Remember the delivery to the first TEGA oven.

[Paul Fjeld]

http://planetary.s3.amazonaws.com/data/pho...9_16B80MDM1.jpg, which was taken at 07:55, which was after the dumping (which happened some time between 07:33 and 07:49).

This is a slightly more exposed picture taken at 7:51 and shows a bit more clearly that the >left< side blob of (wonderful icy) material let go but not the middle nor right. Hence door #1 got the best part of the sample! Just bad stinkin' luck!

Paul

[JRehling]

What's most annoying is that with sublimation, the sample isn't going to just sit there until something works.

[Deimos]

1) hold the scoop so that material should fall out.
2) take dump image
2) turn on the rasp (BBBBRRRATTTTTT!!)
3) take post dump image

You left out :

step 2.5) repeat the above 3 times
step 4) ???
step 5) profit!

[Shaka]

These TEGA scoops don't empty unless you hit them juuuuust right.

[climber]

I can also see other good news :
- if the sample adhere in the scoop this is probably ice (at least on Earth, it's what we'd had say)
- some get into the oven, so it doesn't stuck on the screen

I very confident "we" will make it

[jmknapp]

The way the soil clumps and adheres suggests a fair bit of water, like it's either wet or was wet and froze again--the RASP generates some heat, no?

Probably not a whole lot of time for idle experiments, but if soil adhering to the back of the scoop comes loose in some hours, would that suggest that its water content is responsible?

[babboxy]

mankind always struggles with ice

[BrianL]

So, if this sample is stuck in there, how are they going to get it out in preparation for the next scoop attempt?

[Paul Fjeld]

I know silver linings are little annoying, but I find this situation kind of exciting. The TEGA is having problems because Mars is NOT "nominal." That's the point. When the design of the scoop (its width) and the TEGA doors were being "fought over" I wonder where the possibilty of "wet" sticky clods was on the "threat matrix." Way the hell off in 3 sigma territory I bet!

So Peter and the whole team land exactly like they expected in a place that was better than they could have expected and the adventure seemed like a tic tac toe: there're the polygons - they're even cute; there's the ice - we land on a skating rink; there's the pH - keep the life-question-ball rolling; there's the ice sample... wait a second - that's not like the Arctic!

Keep fighting Phoenix team - you're having an adventure along with your heart attacks!

Paul

[elakdawalla]

You left out :

step 2.5) repeat the above 3 times
step 4) ???
step 5) profit!

Okay, that was hilarious.

Since this was a somewhat obscure cultural reference, I think I'll have to point some of you readers to the Underpants Gnomes Business Plan...Wikipedia, what would we do without you?

--Emily

[Juramike]

recent space.com article on Phoenix's delivery attempt with a very misleading headline:

"Mars-lander glitch prevents dirt-baking efforts"

As far as I understand, the machinery is working nicely (="nominally"), it's just that Martian soil is not cooperating.

Perhaps a more accurate headline would be:
"Mars stuff is hard"

[/rant]

[dvandorn]

With apologies to all...

"Comedy is easy. Mars is hard."



-the other Doug

[PDP8E]

A young nasa test pilot and an eager JPL engineer working on the scoop fix

[01101001]

So, if this sample is stuck in there, how are they going to get it out in preparation for the next scoop attempt?

Looks relatively clean in this, sol 61, 1318 local time:

[jmjawors]

Did they empty the scoop onto MECA?

[Image]

[fredk]

The way the soil clumps and adheres suggests a fair bit of water, like it's either wet or was wet and froze again--the RASP generates some heat, no?

Apparently yes! From the latest update:

[The] robotic arm will use a revised collection-and-delivery sequence overnight Sunday with the goal of depositing an icy soil sample in the lander’s oven... The revised plan includes reducing the length of time the rasp operates as it makes the holes in the trench to reduce any potential heating of the sample, and for increasing the number of times the scoop is vibrated during the sample delivery action.

[mike]

Keep fighting Phoenix team - you're having an adventure along with your heart attacks!

I agree with your entire post. They'll get good results.

[Juramike]

From the update:

NASA's Phoenix Mars Lander’s robotic arm will use a revised collection-and-delivery sequence overnight Sunday with the goal of depositing an icy soil sample in the lander’s oven.

OK.

I'm eating peanuts now.

[ElkGroveDan]

How do they define "overnight Sunday"? MST?

[elakdawalla]

I am virtually certain that they mean "overnight Sunday" Arizona/Pasadena time, which means sol 62, that is, tosol.

Parenthetically: for those of you not familiar with the peculiarities of the federalism that complicates timekeeping in America, the state of Arizona, from which the Phoenix mission is operated, is typically one hour ahead of California, as it is in the Mountain (GMT-7) time zone, while California is in the Pacific (GMT-8) time zone. However, Arizona is one of the two American states (the other is Hawaii, the erstwhile recalcitrant portions of Indiana having chosen to participate as of 2005) that does not observe Daylight Saving Time, with the result that half of the year (including now), Arizona and California are both on the same clock. Unless, that is, you are in a Navajo or other Native American reservation -- which comprises a HUGE portion of the parts of Arizona that a tourist is likely to visit in the summer -- in which case you are an hour ahead of California. God bless America.

--Emily

[fredk]

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? I don't suppose there's too much they could do about that, if the heating is required...

[ElkGroveDan]

Parenthetically: for those of you not familiar with the peculiarities of the federalism that complicates timekeeping in America,

Emily nailed it -- and there's one more exception. Malheur County Oregon. The State of Oregon is on Pacific Time and the State of Idaho is on Mountain time. However there is a town called Ontario, Oregon that is more or less a suburb of Boise Idaho. The nearest Oregon cities are 200-300 miles away. So the county of Malheur of which the vast majority of its population is in Ontario, has chosen to keep Idaho time since that where most of the people there work, shop etc. It sounds simple but of course Westerners being Westerners some folks on the Southern border of Malheur County prefer to think of themselves as Oregonians and not Idahoans, the town of Jordan Valley is the only real community in this region, they prefer to affiliate with their neighbors in Nevada. So even Malheur County is split into two time zones.

For those who are keeping track

[nprev]

Now that's a fascinating factoid, actually! Had no idea, thanks!

IIRC, Clarke had a short story about a robbery in a city on Mars that was on the Prime Meridian, and the plot revolved around temporal confusion...the title completely escapes me, though. Life in the parts you describe must get kinda complicated at times...(dah dah dah, dah!)

[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."

[Paul Fjeld]

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."

I read that as "we're not as scared of the short circuits as we were." Glass half-full interpretation?

Paul

[centsworth_II]

I read that as "we're not as scared of the short circuits as we were."

It does seem quite different from the 'we're treating the next TEGA test as the last' philosophy. If there is any reason to suspect the next TEGA sample would be the last, the next sample MUST be an ice sample.

[Shaka]

Just how vital is it to boil some water vapor from a pristine "ice sample"? We know the ice is there; that white stuff that disappears couldn't be anything else, right? What we want to learn about is what's left behind after the ice vaporizes - organics, or heaven knows what? So why not just position the scoop over the screen and let the sample drop out when it's good and ready? Then cook the important stuff.

Innocence is bliss.

[Juramike]

I read that as, "Well, the stuff is in the oven anyway. If we do manage to deliver ice how are we going to interpret the data with a mixed sample? Might as well cook this one up and be done with it."


With regards to Shaka's question, can they determine the H/D ratio from the evolved stuff?
(If they can, the H/D ratio of the ice would be lost since both would probably sublime equally well within experimental error. So they'd need a fresh ice sample in the oven, not a used and abused concentrate.)

[Paul Fjeld]

Okay, I'm a bit confused.

Peter's comments implied fresh delivery of a dry sample, no? Like oven #0 has spoiled stuff in it. Would they just dump new dry stuff in #0 till it's finally full and then, how do you characterize the result in regard to its context? As NotLurkingAnymore suggests, could #0 just be a delivery test site now? I admit to profound ignorance of the chemistry of all this.

Paul

[centsworth_II]

With regards to Shaka's question, can they determine the H/D ratio from the evolved stuff?

That's my reason for anxiously awaiting TEGA analysis of an ice sample, though I am ignorant as to what info is expected to be gleaned from the ice. I wonder if detecting ice-bound volatile organics is in anyone's wildest dreams as even a small possibility.

[CosmicRocker]

How about picking up some dry soil and tipping it into the back and bottom of the scoop. Then collect the ice cuttings, which would presumably land on top of and/or in front of the dry stuff. Hopefully the layer of dry sediment would prevent the ice from sticking to the metal and it would potentially facilitate the pouring/sprinkling of the ice cuttings from the scoop. Alternatively, perhaps they could "shake up" a mixed sample of ice cuttings and dry sediment by manipulating the scoop/arm. A mixed sample might be easier to deliver to the oven.

It may be that they would prefer to have a sample that was mostly ice, but it seems that they could never assume that any ice sample did not have some admixed soil, so using a little soil to facilitate the sample delivery is probably not a terrible thing.

[Aussie]

Peter's comments implied fresh delivery of a dry sample, no?
Paul

I would anticipate that they will try and get what is left in the scoop in to top up the oven. This will mean that all the material in the oven will have come from from the rasping of the ice material layer. We know that (water) ice is only a part of this layer. I wouldn't like to guess what percentage, but there seems to be a lot of material left after sublimation. So having got rid of all that pesky haich two oh we are left with some pretty valuable material to analyse. Is it the same as the dry upper layer of the regoloth? What surprises does it hold? If there are any organics then they had a better chance of surviving in the opaque ice than in the regolith. Get some to the wet chemistry lab. What is the Ph of this material? Drop a bit into the OM.

Even if the system does fail after the event at least we will have two separate, and valuable data points.

[jmknapp]

It may be that they would prefer to have a sample that was mostly ice, but it seems that they could never assume that any ice sample did not have some admixed soil, so using a little soil to facilitate the sample delivery is probably not a terrible thing.

Seems like some good ideas. If placing some dry material at the back of the scoop is a go, I think that precludes delivering rasped material by the main route (through the back of the scoop around the baffles), but they could still scrape up the icy tailings with the front blade & they'd end up on top of the dry material. Said material might also act like an insulator if the problem is that the scoop itself is warm & melting the sample.

It depends on whether this material is just inherently clumpy/sticky no matter what Phoenix does (like floam ) or, say, if it's the heat generated by rasping and/or the rasp motor that causes it to clump. Maybe they could produce a good bit of tailings and leave them on the surface for a little while. Assuming they are granular and ingestible by TEGA at that stage, put the scoop in the shade for an hour or whatever to let it cool off completely, and then scrape up the tailings. They would have sublimed to some extent, but not completely, and maybe the grains would be a bit smaller--better to get through the screen.

[MahFL]

My take is they can't get an icy sample into the oven, despite their best efforts . It makes sense to go ahead with a "dry" sample as the clock is ticking. Also the spacecraft could at anytime fail, and that would be the end of the mission.