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Unmanned Spaceflight.com _ Phoenix _ TEGA - Round 2

Posted by: djellison Jul 19 2008, 12:04 PM

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



Posted by: rob66 Jul 19 2008, 12:10 PM

ping! spring! boing !

A beautiful sight smile.gif


Posted by: Stu Jul 19 2008, 12:19 PM

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

Posted by: nprev Jul 19 2008, 01:03 PM

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

Posted by: Tesheiner Jul 19 2008, 01:09 PM

"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> smile.gif

Posted by: Reckless Jul 19 2008, 01:23 PM

Sproing indeed smile.gif smile.gif

Posted by: dmg Jul 19 2008, 03:14 PM

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.

Posted by: djellison Jul 19 2008, 06:41 PM

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

 

Posted by: centsworth_II Jul 19 2008, 07:12 PM

Question from old TEGA thread:

QUOTE (jmknapp)
.....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.

Posted by: Shaka Jul 19 2008, 07:18 PM

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

Posted by: climber Jul 19 2008, 07:39 PM

QUOTE (djellison @ Jul 19 2008, 08:41 PM) *
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

Posted by: belleraphon1 Jul 19 2008, 07:56 PM

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

What a beautiful sight ...... !!!!!!!! smile.gif

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

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

Craig

Posted by: CosmicRocker Jul 20 2008, 05:43 AM

QUOTE (climber @ Jul 19 2008, 01:39 PM) *
I was looking for the anaglyph to be very very very sure. I can confirm now : it's open! ...
biggrin.gif biggrin.gif Hilarious, climber! That's a good one. biggrin.gif biggrin.gif

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

Posted by: jmknapp Jul 20 2008, 12:37 PM

QUOTE (centsworth_II @ Jul 19 2008, 02:12 PM) *
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"" http://cboh.org/~jmk/tegasound.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

Posted by: Solar Fan Jul 22 2008, 03:28 AM

Yea!

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

Posted by: Cargo Cult Jul 22 2008, 08:48 AM

QUOTE (Solar Fan @ Jul 22 2008, 04:28 AM) *
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!)


Posted by: Ken McLean Jul 23 2008, 10:58 AM

QUOTE (Cargo Cult @ Jul 22 2008, 06:48 PM) *
(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.

Posted by: centsworth_II Jul 23 2008, 03:07 PM

QUOTE (Ken McLean @ Jul 23 2008, 06:58 AM) *
...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.

Posted by: BrianL Jul 23 2008, 05:07 PM

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


Posted by: Skyrunner Jul 23 2008, 06:07 PM

QUOTE (BrianL @ Jul 23 2008, 07:07 PM) *
My momma always said, "TEGA is like a box of chocolates. You never know what you're gonna get." smile.gif

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.

Posted by: TheChemist Jul 23 2008, 09:25 PM

Apologies, the wait is too long smile.gif


 

Posted by: Skyrunner Jul 25 2008, 08:13 AM

Wow, thanks to http://www.planetary.org/blog/article/00001569/ 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:

QUOTE
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!

Posted by: Deimos Jul 25 2008, 02:24 PM

QUOTE (Skyrunner @ Jul 25 2008, 09:13 AM) *
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.

Posted by: Skyrunner Jul 25 2008, 06:17 PM

QUOTE (Deimos @ Jul 25 2008, 04:24 PM) *
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.

Posted by: jmjawors Jul 25 2008, 06:31 PM

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. biggrin.gif 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.

Posted by: akuo Jul 25 2008, 11:42 PM

Looks like they are finally http://phoenix.lpl.arizona.edu/07_25_pr.php

QUOTE
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?

Posted by: bcory Jul 26 2008, 01:33 AM

"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/story_channel.jsp?channel=busav&id=news/EXCITE07258.xml

Posted by: Aussie Jul 26 2008, 03:15 AM

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.

Posted by: 1101001 Jul 26 2008, 03:46 PM

http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=179

This looks like post-delivery, 0749 local time. There's a little soil on the adjacent TEGA door.
http://phoenix.lpl.arizona.edu/images.php?gID=16019&cID=179

Posted by: fredk Jul 26 2008, 04:05 PM

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

Posted by: jamescanvin Jul 26 2008, 04:08 PM

Here is a before and after gif.

 

Posted by: Juramike Jul 26 2008, 04:26 PM

QUOTE (fredk @ Jul 26 2008, 11:05 AM) *
They certainly got some serious rasping done:
http://phoenix.lpl.arizona.edu/images/gallery/lg_16036.jpg



Awesome! All that's missing is http://www1.superpit.com.au/vids/280-1119.asf. (4 MB, but worth it smile.gif )

Posted by: imipak Jul 26 2008, 05:11 PM

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.

Posted by: ugordan Jul 26 2008, 05:29 PM

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...

Posted by: Reckless Jul 26 2008, 05:43 PM

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

Posted by: 1101001 Jul 26 2008, 06:17 PM

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?gID=16019&cID=179

There is an image of soil remaining in the scoop, at 0755, after the above:
http://phoenix.lpl.arizona.edu/images.php?gID=16109&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.)

Posted by: centsworth_II Jul 26 2008, 06:37 PM

QUOTE (imipak @ Jul 26 2008, 01:11 PM) *
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?

Posted by: imipak Jul 26 2008, 08:00 PM

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.

Posted by: Shaka Jul 26 2008, 08:24 PM

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

Posted by: BrianL Jul 26 2008, 08:55 PM

Yeah, what's the scoop? laugh.gif

Sorry, couldn't resist...

Posted by: akuo Jul 26 2008, 10:24 PM

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

Posted by: TheChemist Jul 26 2008, 10:33 PM

Well, there is also some good news in there : smile.gif

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

Posted by: dvandorn Jul 26 2008, 10:43 PM

QUOTE (akuo @ Jul 26 2008, 05:24 PM) *
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

Posted by: elakdawalla Jul 26 2008, 10:49 PM

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/phoenix/raw/RS060EFF901519999_16B80MDM1.jpg, which was taken at 07:55, which was after the dumping (which happened some time between 07:33 and 07:49).

--Emily

Posted by: akuo Jul 26 2008, 10:49 PM

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.

Posted by: Stu Jul 26 2008, 10:54 PM

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. sad.gif 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.

Posted by: slinted Jul 26 2008, 11:19 PM

Here's an RAC image of the sample before the sprinkle/dump, for comparison:
http://www.lyle.org/~markoff/collections/RS060EFF901518355_16B10MRM1.jpg
RGB from http://planetary.s3.amazonaws.com/data/phoenix/raw/RS060EFF901518355_16B10MRM1.jpg acquired at 07:29 and http://planetary.s3.amazonaws.com/data/phoenix/raw/RS060EFF901518418_16B10MBM1.jpg taken at 07:30

Posted by: ArizonaWildcat Jul 26 2008, 11:19 PM

QUOTE (Stu @ Jul 26 2008, 02:54 PM) *
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. sad.gif 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.

Posted by: Shaka Jul 27 2008, 12:03 AM



I can't stand it.

Posted by: belleraphon1 Jul 27 2008, 12:18 AM

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





Posted by: PDP8E Jul 27 2008, 01:28 AM

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

Posted by: jmjawors Jul 27 2008, 02:11 AM

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

Posted by: Paul Fjeld Jul 27 2008, 02:20 AM

QUOTE (elakdawalla @ Jul 26 2008, 06:49 PM) *
http://planetary.s3.amazonaws.com/data/phoenix/raw/RS060EFF901519999_16B80MDM1.jpg, which was taken at 07:55, which was after the dumping (which happened some time between 07:33 and 07:49).

http://phoenix.lpl.arizona.edu/images/gallery/lg_16105.jpg 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

Posted by: JRehling Jul 27 2008, 02:26 AM

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

Posted by: Deimos Jul 27 2008, 03:34 AM

QUOTE (PDP8E @ Jul 27 2008, 02:28 AM) *
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!
unsure.gif

Posted by: Shaka Jul 27 2008, 05:12 AM


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

Posted by: climber Jul 27 2008, 06:41 AM

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

Posted by: jmknapp Jul 27 2008, 11:22 AM

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?

Posted by: babboxy Jul 27 2008, 11:28 AM

mankind always struggles with ice


Posted by: BrianL Jul 27 2008, 02:10 PM

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

Posted by: Paul Fjeld Jul 27 2008, 02:25 PM

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

Posted by: elakdawalla Jul 27 2008, 03:08 PM

QUOTE (Deimos @ Jul 26 2008, 07:34 PM) *
You left out :

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

biggrin.gif 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 http://en.wikipedia.org/wiki/Underpants_Gnomes#The_Gnomes...Wikipedia, what would we do without you?

--Emily

Posted by: Juramike Jul 27 2008, 03:46 PM

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

http://www.space.com/missionlaunches/080727-phoenix-update.html

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]

Posted by: dvandorn Jul 27 2008, 04:16 PM

With apologies to all...

"Comedy is easy. Mars is hard."

smile.gif

-the other Doug

Posted by: PDP8E Jul 27 2008, 05:17 PM



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

Posted by: 1101001 Jul 27 2008, 06:20 PM

QUOTE (BrianL @ Jul 27 2008, 06:10 AM) *
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:
http://phoenix.lpl.arizona.edu/images.php?gID=16221&cID=181

Posted by: jmjawors Jul 27 2008, 07:01 PM

Did they empty the scoop onto MECA?

[http://phoenix.lpl.arizona.edu/images.php?gID=16239&cID=181]

Posted by: fredk Jul 27 2008, 09:29 PM

QUOTE (jmknapp @ Jul 27 2008, 11:22 AM) *
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 http://phoenix.lpl.arizona.edu/07_27_pr.php
QUOTE
[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.

Posted by: mike Jul 27 2008, 09:49 PM

QUOTE (Paul Fjeld @ Jul 27 2008, 06:25 AM) *
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.

Posted by: Juramike Jul 27 2008, 10:57 PM

From the update:

QUOTE
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.

Posted by: ElkGroveDan Jul 28 2008, 12:18 AM

How do they define "overnight Sunday"? MST?

Posted by: elakdawalla Jul 28 2008, 03:06 AM

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. rolleyes.gif

--Emily

Posted by: fredk Jul 28 2008, 03:11 AM

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...

Posted by: ElkGroveDan Jul 28 2008, 03:31 AM

QUOTE (elakdawalla @ Jul 27 2008, 07:06 PM) *
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. http://www.timetemperature.com/tzus/current_time_in_oregon.shtml. 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 rolleyes.gif

Posted by: nprev Jul 28 2008, 03:50 AM

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!)

Posted by: Floyd Jul 28 2008, 04:36 AM

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

-Floyd

Posted by: climber Jul 28 2008, 06:44 AM

QUOTE (ElkGroveDan @ Jul 28 2008, 05:31 AM) *
even Malheur County is split into two time zones.

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

Posted by: djellison Jul 28 2008, 07:05 AM

QUOTE (fredk @ Jul 28 2008, 04:11 AM) *
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

Posted by: jmknapp Jul 28 2008, 09:29 AM

QUOTE (fredk @ Jul 27 2008, 11:11 PM) *
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 smile.gif :



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?

Posted by: NotLurkingAnymore Jul 28 2008, 10:11 AM

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

Posted by: TheChemist Jul 28 2008, 11:12 AM

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.

Posted by: BrianL Jul 28 2008, 03:39 PM

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

Posted by: jamescanvin Jul 28 2008, 04:45 PM

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!

Posted by: djellison Jul 28 2008, 04:49 PM

QUOTE (BrianL @ Jul 28 2008, 04:39 PM) *
Want news...


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



Posted by: jmknapp Jul 28 2008, 05:01 PM

QUOTE (BrianL @ Jul 28 2008, 11:39 AM) *
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?gID=16417&cID=183

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


Posted by: ElkGroveDan Jul 28 2008, 05:43 PM

The icy soil in the Mars environs, looks and seems to behave like http://www.buyfloam.com/?cid=132025here on Earth at STP. Maybe they should try that in their test bed to see how best to manipulate the samples on Mars.

Posted by: Juramike Jul 28 2008, 05:59 PM

QUOTE (ElkGroveDan @ Jul 28 2008, 12:43 PM) *
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:

http://chemistry.about.com/od/chemistryhowtoguide/ht/floam.htm

-Mike

Posted by: brellis Jul 28 2008, 06:35 PM

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

Posted by: NotLurkingAnymore Jul 28 2008, 09:23 PM

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.

Posted by: 1101001 Jul 29 2008, 01:35 AM

Failed again. Not enough delivered to TEGA.

http://www.jpl.nasa.gov/news/phoenix/release.php?ArticleID=1808 (July 28)

QUOTE
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."

Posted by: Paul Fjeld Jul 29 2008, 01:47 AM

QUOTE
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

Posted by: centsworth_II Jul 29 2008, 02:13 AM

QUOTE (Paul Fjeld @ Jul 28 2008, 09:47 PM) *
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.

Posted by: Shaka Jul 29 2008, 02:26 AM

blink.gif 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.

smile.gif Innocence is bliss.

Posted by: Juramike Jul 29 2008, 02:48 AM

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.)

Posted by: Paul Fjeld Jul 29 2008, 03:20 AM

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

Posted by: centsworth_II Jul 29 2008, 03:23 AM

QUOTE (Juramike @ Jul 28 2008, 09:48 PM) *
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.


Posted by: CosmicRocker Jul 29 2008, 04:04 AM

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. unsure.gif 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.

Posted by: Aussie Jul 29 2008, 09:01 AM

QUOTE (Paul Fjeld @ Jul 29 2008, 04:20 AM) *
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.

Posted by: jmknapp Jul 29 2008, 10:56 AM

QUOTE (CosmicRocker @ Jul 28 2008, 11:04 PM) *
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 laugh.gif) 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.

Posted by: MahFL Jul 29 2008, 12:19 PM

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.

Posted by: centsworth_II Jul 29 2008, 01:06 PM

QUOTE (Shaka @ Jul 28 2008, 09:26 PM) *
Just how vital is it to boil some water vapor from a pristine "ice sample"?


http://www.livescience.com/space/scienceastronomy/080520-st-mars-lander-science.html sums it up pretty well:
One of the key measurements Phoenix is designed to make is the abundance of the different isotopes of hydrogen and oxygen in the water ice.... Phoenix's mass spectrometer will measure the ratios of the isotopes of these two elements, "and that should be a signature of the processes involved in making that ice," Arvidson said.

Here is what those details could reveal about ice on Mars: One theory is that the ice is in equilibrium with the scant amount of water vapor in Mars' atmosphere and froze out of the air and into the pore spaces between the soil grains.... If the mass spec examines the isotopic ratios of the water and the air "and if they're identical, it means that the water in the atmosphere is in contact, in equilibrium with the ice," Arvidson explained.

"But suppose it's a different isotopic composition — it means that ice was inplaced in some other time, when water in the atmosphere had a different isotopic composition," Arvidson told SPACE.com. "So we're trying to get at the past history and the role of water at the high latitudes."

Posted by: Shaka Jul 29 2008, 07:43 PM

Good answer! Thanks, $.02.
Both the H2O and the residue are interesting, and we will, hopefully, get to cook up both from a single sample.
But we also have strategies for doing them separately.

Posted by: Ant103 Jul 30 2008, 11:54 AM

Color pan of the deck on Sol 61 smile.gif
http://www.db-prods.net/blog/wp-content/uploads/2008/07/sol61-deckpan.jpg

Posted by: nprev Jul 30 2008, 12:01 PM

Absolutely beautiful, Ant; just like being there! Thank you. smile.gif

Posted by: remcook Jul 30 2008, 12:43 PM

Indeed! Seeing lots of Earth-based stuff in the frame makes it more 'real'. Great colors.

Posted by: 1101001 Jul 30 2008, 09:39 PM

This should be enough for an oven run on samples with the ice sublimated out. (http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=189, 1127 local time)

http://phoenix.lpl.arizona.edu/images.php?gID=16837&cID=189

Posted by: slinted Jul 31 2008, 05:05 AM

Here's a color view from SSI taken around the same time on sol 64:
http://www.lyle.org/~markoff/processed/SS064ESF901887879_172D0R6.jpg

Posted by: Astro0 Jul 31 2008, 05:52 AM

Animation of the sample dump.


Posted by: Shaka Jul 31 2008, 06:03 AM

Danged oven must be full by now!
Let's get cookin'!
wheel.gif

Posted by: peter59 Aug 7 2008, 10:10 PM

It looks like .... loading oven #5 ??



Posted by: akuo Aug 7 2008, 10:15 PM

http://www.met.tamu.edu/mars/directory.html says tosol's (sol 72) tasks were "RR3 acquire, delivery, and site documentation; atmo and surface remote sensing"

RR3 must be a TEGA sample, but what is it?

Posted by: 1101001 Aug 7 2008, 10:17 PM

QUOTE (akuo @ Aug 7 2008, 02:15 PM) *
RR3 must be a TEGA sample, but what is it?


My guess "Rosy Red 3". I don't recall a Rosy Red 2. But Snow White was imaged a lot this sol, and Rosy Red came from near Snow White (and went into the MECA). This is probably an attempt to take a suspect perchlorate sample cousin and look for more confirmation with TEGA.

Posted by: slinted Aug 7 2008, 11:16 PM

Here's the color view of TEGA from sol 72 after delivery
http://www.lyle.org/~markoff/processed/SS072ESF902596348_18330R6.jpg

Posted by: tanjent Aug 8 2008, 01:39 AM

I don't know if the topic line here is broad enough to embrace speculation about alternative sample delivery mechanisms, but as I watch the tailings pile up around the TEGA doors, I can't help wondering if a vacuum cleaner could be devised to work in a low-pressure Mars environment. If so, some future mission might want to include one. Earthly vacuum cleaners do a pretty efficient job of delivering their dust and soil samples into the little paper bag - it would be nice if we had one up there we could just command to "suck this little patch of digging debris into oven number n". And when it wasn't doing science it could even clean up after itself.- keeping the lander deck photogenically neat and tidy. Discharging the vacuumed materials where they won't come back to contaminate future samples could pose a problem, but so far it doesn't look like the existing design handles that issue very well either. In science and engineering, elegant solutions usually look, well, elegant. What could be more elegant than a robot on Mars with housekeeping capabilities?

Posted by: James Sorenson Aug 8 2008, 06:08 AM

Looking at slinted's color image of the soil that has fallen on the top's of those doors, when those doors open, I cant help but think that is gonna just slide into the oven as a contaminate sample.

Posted by: centsworth_II Aug 8 2008, 07:29 AM

QUOTE (James Sorenson @ Aug 8 2008, 01:08 AM) *
...I cant help but think that is gonna just slide into the oven as a contaminate sample.

It does look like once the next oven opens, it will be hard to avoid having soil from the ridge slide into it.

http://phoenix.lpl.arizona.edu/images.php?gID=18949&cID=207

Posted by: bgarlick Aug 8 2008, 05:16 PM

Yes, it does appear that now *every* remaining oven has at least some soil perched above its door so that when it is opened some soil may fall in. Pure, controlled, TEGA sampling and testing no longer looks possible.

A vacuum was suggested, but what about a simple coring mechanism on the end of the arm for taking core samples of soil or ice and then delivering/extruding them into on-deck instruments precisely with no spill. Maybe in 20-20 hindsight such a simple mechanism may have worked better.

(The funnel shaped channel in the bottom of the scoop looks like it could have better directed sample delivery, but it does not seem to work because of the clumpyness. In dry powder-like simulants I am sure it does a fine job of precise sample delivery...)

Posted by: ElkGroveDan Aug 8 2008, 05:21 PM

QUOTE (bgarlick @ Aug 8 2008, 09:16 AM) *
Maybe in 20-20 hindsight such a simple mechanism may have worked better.


Maybe it was proposed, evaluated and ruled out for any number of reasons already.

Posted by: jmknapp Aug 8 2008, 06:22 PM

QUOTE (tanjent @ Aug 7 2008, 08:39 PM) *
And when it wasn't doing science it could even clean up after itself.- keeping the lander deck photogenically neat and tidy.


An early proposal:



Posted by: Greg Hullender Aug 8 2008, 11:56 PM

Wouldn't it be simpler to devise something to blow the area clean after each experiment? Seems to me it'd be difficult to get suction in a near vacuum.

--Greg

Posted by: 1101001 Aug 9 2008, 06:47 PM

TEGA oven #5 not full yet

http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080809.html (2008 August 9)

QUOTE
"There appear to be clumps blocking the opening," said Doug Ming of NASA Johnson Space Center, Houston, the Phoenix team's science lead on Friday. "However, we have seen in the past that when this soil sits for a while, it disperses. We intend to fill an oven with this material, either by additional vibration of the same screen or by opening doors to one of the other TEGA cells."

Posted by: ZenDraken Aug 9 2008, 09:56 PM

QUOTE (Greg Hullender @ Aug 8 2008, 04:56 PM) *
Wouldn't it be simpler to devise something to blow the area clean after each experiment? Seems to me it'd be difficult to get suction in a near vacuum.

--Greg

A compressed air system would add considerable complexity, weight, and power demand. But a small brush would work and be really simple and lightweight.

I keep saying robotic missions should include some basic tools. These would have been really handy on Phoenix:
1. A prybar: just a metal probe, to push, pull, pry, or whatever's needed. (forcing open TEGA doors)
2. A brush for general cleaning, (like cleaning TEGA). Another brush mounted to the lander somewhere would be handy for cleaning sticky stuff out of the scoop.

These could have been permanently built-in to the RA, perhaps on the back of the scoop, no need for extra moving parts.

A hammer of some sort might be useful but would probably require a solenoid actuator, which means added complexity, weight, and power draw. Always KISS (Keep It Simple Stupid) or you're just adding problems.

Posted by: ilbasso Aug 9 2008, 10:01 PM

Don't forget duct tape. Can't go on a long trip without duct tape. And a Swiss Army knife.

Posted by: djellison Aug 10 2008, 12:31 AM

QUOTE (ZenDraken @ Aug 9 2008, 10:56 PM) *
Always KISS (Keep It Simple Stupid) or you're just adding problems.


That's exactly how I would describe your entire suggestion.

Which parts of the instrument payload would you sacrifice for your additions, MECA, TEGA or LIDAR. Your call.

Doug

Posted by: JRehling Aug 10 2008, 12:45 AM

What about just having the surface be sloped 45 degrees? Try to beat that for no-moving-parts.

Posted by: ElkGroveDan Aug 10 2008, 12:47 AM

QUOTE (ZenDraken @ Aug 9 2008, 01:56 PM) *
I keep saying robotic missions should include some basic tools. These would have been really handy on Phoenix:


Even better, the Opportunity lander should have included some wire, automated pliers and a soldering gun. Then it would have been able to fix the short that kept the arm heater on. Spirit should have included a power wrench so they could have removed the stuck wheel. The Mars Climate Orbiter should have included a subroutine that responded with "Are you sure you meant to send those orbital insertion instructions in imperial units and not metric?" And of course, we all know Apollo 13 should have had spare oxygen tanks and a redundant secondary electrical system.

Posted by: Juramike Aug 10 2008, 02:12 AM

Or how about just a simple paper clip? Works for MacGyver....

http://www.macgyveronline.org/pages/macgyverisms.html

Posted by: gallen_53 Aug 10 2008, 04:11 AM

QUOTE (ElkGroveDan @ Aug 10 2008, 01:47 AM) *
Even better, the Opportunity lander should have included some wire, automated pliers and a soldering gun. Then it would have been able to fix the short that kept the arm heater on. Spirit should have included a power wrench so they could have removed the stuck wheel. ..


How about: Send along an astronaut and if something breaks, he/she can fix it.

Posted by: BrianL Aug 10 2008, 04:52 AM

QUOTE (djellison @ Aug 9 2008, 06:31 PM) *
Which parts of the instrument payload would you sacrifice for your additions, MECA, TEGA or LIDAR. Your call.


That's a pretty easy call, given that TEGA seems neither particularly well thought out or implemented.

Posted by: Greg Hullender Aug 10 2008, 05:45 AM

QUOTE (djellison @ Aug 9 2008, 05:31 PM) *
Which parts of the instrument payload would you sacrifice for your additions, MECA, TEGA or LIDAR. Your call.


Hardware's not my strong suit, but is it truly so difficult to have multiple attachments on the robotic arm? I can see how multiple scientific instruments would be tough, but "dumb" attachments like a pick and a brush don't seem like they should sink the boat.

Anyone know if anything like that was even considered?

--Greg

Posted by: Deimos Aug 10 2008, 06:06 AM

QUOTE (Greg Hullender @ Aug 10 2008, 05:45 AM) *
Anyone know if anything like that was even considered?


Similar things were considered, such as a scoop brush. The scoop currently has a drill and a TECP. It is near a camera. Any scoop-end device would have to be dealt with in ops--TECP greatly complicates RAC and limits how close to the surface it can take pictures. Put a brush near it, make the brush stay clean when the TECP is inserted, and I could see you might have problems. Then you have to deal with degrees of freedom--using a wrist-mounted brush to clean TEGA would be tricky. You have 6 degrees of freedom with something held in your fingers, which is enough to hold something where you want it, oriented how you want it. The most you can get out of the RA is 4 degrees of freedom, you you have a trade between where you want it and how you want it aimed.

Posted by: Stu Aug 10 2008, 06:23 AM

QUOTE (ilbasso @ Aug 9 2008, 11:01 PM) *
Don't forget duct tape. Can't go on a long trip without duct tape. And a Swiss Army knife.


... and a towel. Space travellers should never go anywhere without a towel, as the Guide says. smile.gif

Posted by: djellison Aug 10 2008, 09:47 AM

QUOTE (BrianL @ Aug 10 2008, 05:52 AM) *
That's a pretty easy call, given that TEGA seems neither particularly well thought out or implemented.


And that is an utterly lousy call given that we have successfully delivered two sample, and have plenty of opportunities left to deliver more.

Posted by: Juramike Aug 10 2008, 11:34 AM

QUOTE (BrianL @ Aug 10 2008, 12:52 AM) *
That's a pretty easy call, given that TEGA seems neither particularly well thought out or implemented.


I disagree.

Cooking and sniffing the subsurface of Mars is the reason Phoenix went there in the first place.

Posted by: BrianL Aug 10 2008, 01:58 PM

Of course TEGA is a necessary instrument. The suggestion was tongue in cheek. I simply felt that, with his challenge, Doug opened the door for injecting a bit of criticism.

Edit: I've taken out some additional comments. I'm a bit crankier than usual from having buggered up my back yesterday, cleaning algae off the fish tank, of all things.

Posted by: ZenDraken Aug 10 2008, 03:01 PM

QUOTE (djellison @ Aug 9 2008, 04:31 PM) *
That's exactly how I would describe your entire suggestion.

Which parts of the instrument payload would you sacrifice for your additions, MECA, TEGA or LIDAR. Your call.

Doug


"KISS" is a widely used though informal engineering term, not something I just made up. It's generally considered to be a good thing, not a criticism.

My fault for using "prybar", which implies the kind of heavy steel thing you can buy at a hardware store. I meant that as an analogy, not a description. In my mind, I was really picturing something like a small screwdriver or even a dental pick.

The "brush" (again, in my imagining) would be along the lines of a large artist's brush, perhaps an inch wide.

I can't imagine those two items adding more than a few ounces. If Phoenix had them right now, they could at least attempt to "pry" open the TEGA doors, and brush away the excess soil.

Posted by: Phil Stooke Aug 10 2008, 03:32 PM

I don't think the addition of the hardware is the show-stopper here, except for the mass which is always an issue. The biggest problem is likely to be whether the RA can be used for such actions - can it physically do it, can the procedures be managed successfully, can it do so without damaging itself or something else?

Phil

Posted by: ZenDraken Aug 10 2008, 04:31 PM

Phil: Understood. As always, it's a risk/reward tradeoff. Would the cost of adding these tools be worth the added weight and risk penalty? I think it would be. I'm not prepared to back that up with rigorous analysis, but I can point to the difficulties with TEGA as an example. It would have been really helpful to have the option pry open the doors or brush away excess dirt, and it would not have required more than a few extra ounces of equipment.

Of course the problems with TEGA were unforeseen, but that's why you should always bring some generic tools when you are far from help. You never know what you're going to need.

And: I don't in any way mean to be critical of the people who developed and built TEGA. They and the whole Phoenix team have done a magnificent job on a planet that tends to eat spacecraft. I'm just being a Monday morning quarterback here.

Posted by: djellison Aug 10 2008, 04:32 PM

What do you use to unstick the pry-bar when it gets stuck?

Just saying smile.gif

Posted by: ZenDraken Aug 10 2008, 04:47 PM

Good point. A hook could potentially get snagged. A tapered probe could also get wedged into something. A thin straight-sided probe may be the lowest-risk design.

Brush bristles could also get snagged in the joint between metal plates. Obviously this would all need to be designed and tested well, and only used when absolutely necessary. But I think it would be a good risk trade off, and could actually reduce risk for accomplishing the overall mission goals.

Posted by: Reckless Aug 10 2008, 05:39 PM

Thinking up add-ons is always a good exercise as they all have one flaw or other. but on the mass subject does anybody know how they came to decide on the size of the scoop. To me it seems to be a little large when compared to the instruments it serves.
I suppose it must be related to the actual digging rather than the delivering.

Roy

Posted by: jmknapp Aug 10 2008, 06:35 PM

QUOTE (Reckless @ Aug 10 2008, 12:39 PM) *
I suppose it must be related to the actual digging rather than the delivering.


What if they had to go down a foot or more to hit ice--better to have large scoop?

Posted by: Juramike Aug 10 2008, 08:25 PM

The backpacker's adage:

"If you've got it and you don't need it, it's worthless.
if you need it and you don't got it, it's priceless."

Posted by: 1101001 Aug 10 2008, 09:33 PM

Let the baking begin.

http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080809.html (2008 August 9)

QUOTE
Update, Aug. 10, 8 a.m. PDT:
Vibration of the screen above a laboratory oven on NASA's Phoenix Mars Lander on Saturday succeeded in getting enough soil into the oven to begin analysis. Commands were sent for the lander's Thermal and Evolved-Gas Analyzer to begin analysis Sunday of the soil sample from a trench called "Rosy Red."

Posted by: akuo Aug 10 2008, 09:50 PM

Nice. I was getting worried.

The team has to get a grip of the properties of the Martian soil, if the want to get that ice sample. I think the previous word was that they had the sprinkling method figured out for this oven #5, but we still saw troubles.

For the ice sample they must figure how to get the ice unstuck from back of the scoop AND how to get it through the TEGA screen in one go. The sticking to the scoop is strange though, because the ice obviously moves through the complex maze from the rasp to the actual scoop. Maybe the time just needs to be shorter from rasping to the actual delivery drop.

Posted by: Oersted Aug 10 2008, 10:24 PM

Kudos to the JPL for getting SO MANY things right in this mission (and with the MERs) that people seem to forget how difficult interplanetary exploration really is! - Phoenix landed perfectly. It perfectly initiated ground operations. Its landing ground perfectly corresponded to the analysis of the orbital reconnaissance. Everything functions perfectly well into the prime mission period.

It really seems necessary to remind some that this lander wasn't built with the benefit of hindsight. It wasn't built with limitless time- and financial constraints either. Truth is, it was an incredible intellectual feat to create a lander that turned out to fit so well with the task set before it and the environment encountered.

I remember when we were mostly looking at smoking holes as the results of our our attempts to land on the surface of Mars. Now we bitch over a shovel spilling a little bit of dirt beside a receptacle.... Wonderful times!

Posted by: nprev Aug 10 2008, 10:29 PM

Well said.

The other thing to keep in mind is that engineering is as least as much art as science. Everything looks perfect on paper, in demo, in test...then reality & unexpected factors intrude when the rubber meets the road, always. Solution: Adapt & overcome for the present situation, then figure out how to do it better next time. It's all iterative.

(For those philosophically inclined, even the smallest design project provides conclusive proof that determinism is a totally false concept... rolleyes.gif )

Posted by: belleraphon1 Aug 11 2008, 12:24 AM

All well said... I think this team and Phoenix are a marvel.

And, ya know...... I find it just as fascinating that the soil does NOT behave according to the models. That is telling us something significant. We just have to figure it out, and in the process we will learn new stuff (nice technical term rolleyes.gif ) about Mars and this polar environment.

I remember the long dry spell of the 80's.......

Luv every bit of it this now..... smile.gif

Craig


Posted by: Stephen Aug 11 2008, 08:47 AM

We need to cut the TEGA and MECA teams some slack. They're essentially pioneering new classes of instruments on Mars. Unforeseen problems (eg the clumpy nature of the Martian soil) as well as hiccups of one kind or another were pretty much inevitable. We should be glad the problems they have endured have not only been solveable but have not been worse!

Their experience does, however, raise the question of the SAM and ChemMin instruments on the MSL. They will be ingesting and processing samples of Mars too. Will there be enough time for the people in charge of designing and building those to digest the experiences of Phoenix and make any appropriate changes or are their instruments (and their sample delivery systems) sufficiently different that we don't need to worry? Or is it a case that it is now too late in the day for any changes (given that the mission is due to launch next year) and all we can do is wring our hands and pray that SAM and ChemMin don't encounter any clumpy soil or find an occasion to wish the MSL had included among its bag of tricks a small brush, air blower, or some suitable tool to push, lift, or pry open recalcitrant sample entry doors? :-(

======
Stephen

Posted by: djellison Aug 11 2008, 09:13 AM

I think they will be mainly rock-munching, and that makes for a much more managable medium in many respects.

Doug

Posted by: centsworth_II Aug 11 2008, 03:58 PM

QUOTE (Stephen @ Aug 11 2008, 04:47 AM) *
...Will there be enough time for the people in charge of designing and building those to digest the experiences of Phoenix and make any appropriate changes...

I think the major lesson will be learning how a part "not manufactured to specifications" finds its way into a flight instrument and its crippling effects remain undetected in testing. Without this unfortunate circumstance nobody would be talking about the need for a pry bar.

Posted by: fredk Aug 11 2008, 06:16 PM

QUOTE (djellison @ Aug 11 2008, 10:13 AM) *
... munching, and that makes for a much more managable medium...

Mmmmmm... alliteration! laugh.gif tongue.gif

Posted by: MahFL Aug 11 2008, 06:18 PM

Did you see the heavy duty drill they have on MSL ?

Posted by: ZenDraken Aug 11 2008, 08:02 PM

QUOTE (MahFL @ Aug 11 2008, 10:18 AM) *
Did you see the heavy duty drill they have on MSL ?

Speaking of tools, http://marsprogram.jpl.nasa.gov/msl/spotlight/20080630.html

This was interesting:

QUOTE
The drill is so strong it can hold the rover in place even if all six of its wheels slip on a 20-degree slope. If the drill gets stuck in a rock, the rover can hammer and spin the drill to pull it back out. As a last resort, the rover can release the drill bit and replace it with one of the extras on board.

Hammer*, drill, and detachable bits! Next thing you know, they'll add pry bars and brushes!

(*I know, it's not really a hammer, but they used the word "hammer")

Posted by: Ipparchus Aug 13 2008, 08:23 AM

Do you know if Phoenix is going to use all 8 TEGA ovens it has or 7 of the 8. Is it going to keep one without a sample soil, for using it as a test cell? do you know if the next TEGA samples will be ice or soil samples? is there any meaning aquiring an ice sample for MECA?

Posted by: djellison Aug 13 2008, 08:43 AM

Don't know.
Yes, using the ceramic blank on the deck
Don't know
And no - you don't want Ice in MECA - as it will dilute the chemistry onboard.

Doug

Posted by: Ipparchus Aug 13 2008, 09:10 AM

full inline quote removed


The ceramic blank is with the other 8 TEGA ovens or it is alone on the deck? when are they going to use it?

Posted by: djellison Aug 13 2008, 09:20 AM

It's on the lander deck - they will have to get it with the rasp. As for when....at some point between now and the end of the mission.


Doug

Posted by: Reckless Aug 13 2008, 10:06 AM

I thought the ceramic blank was only going to be used if some organics were found in one of the samples.
Have I missed some more exciting news smile.gif
Roy

Posted by: djellison Aug 13 2008, 10:30 AM

I thought that as well - but it was mentioned in a previous press conf as going ahead anyway.

Doug

Posted by: Reckless Aug 13 2008, 12:29 PM

Thanks Doug
I was going by a paper on the organic free ceramic block from quite a while back and must have missed that press conference.
Roy

Posted by: centsworth_II Aug 13 2008, 09:04 PM

They may test the blank in case organics are detected during data analysis after the data gathering portion of the mission is complete, to avoid the situation of seeing evidence for organics months from now with no blank data to compare it to.

edit: Just my speculation on why they would test the blank even if no organics are detected before hand. If, in fact, they do that.

Posted by: peter59 Aug 15 2008, 05:24 AM

Mark Lemmon's Phoenix SSI raw images directory:
Sol 079: Document grooming of Burn Alive, TA-7 door open; remote sensing.

TEGA's oven #7 door are still closed (Sol 79, 12:00:37 local Mars solar time).
http://phoenix.lpl.arizona.edu/images/gallery/lg_21340.jpg
mad.gif

Posted by: centsworth_II Aug 15 2008, 05:39 AM

QUOTE (peter59 @ Aug 15 2008, 12:24 AM) *
mad.gif

Looks open to me. smile.gif And in the same way number 0 -- I mean #4 -- was. One side all the way, the other partial.
(If you look closely, it's also open in the image you link, just cut off in the image.)

http://phoenix.lpl.arizona.edu/images.php?gID=21316&cID=224

Posted by: peter59 Aug 15 2008, 05:42 AM

QUOTE (centsworth_II @ Aug 15 2008, 05:39 AM) *
Looks open to me. smile.gif And in the same way number 0 was. One side all the way, the other partial.
(If you look closely, it's also open in the image you link, just cut off in the image.)

You are right.

Posted by: Astro0 Aug 15 2008, 06:56 AM

Similar door opening to the very first oven.



Astro0

Posted by: Aussie Aug 15 2008, 08:31 AM

Given that they are trying for an ice sample, and the difficulties previously experienced with this, why the heck are they opening a door on the 'poor performance' side of the TEGA. Logic would seem to dicatate that you go with the successful side to preclude the possibility of (for instance) the arm throwing the claw in and precluding further samples.

Posted by: akuo Aug 15 2008, 08:38 AM

Apparently it isn't for an ice sample. This is a comment from Ray in http://www.planetary.org/blog/article/00001603/:

QUOTE
The goal at Burn Alive is to get a sample from an intermediate depth, a couple centimeters above the ice-soil interface.

Posted by: slinted Aug 15 2008, 09:53 AM

SSI color of TEGA from sol 79
http://www.lyle.org/~markoff/processed/SS079EFF903221476_19030L1.jpg

Also, here's a color blink showing the open doors vs. an unopened background: http://www.lyle.org/~markoff/collections/tega_sol61_79.gif

Posted by: Harkeppler Aug 15 2008, 10:22 AM

Here,

http://www.nasa.gov/mission_pages/phoenix/images/press/AFM-rev3.html

NASA "chemists" inform the public that, if perchlorate were present, TEGA should probably see chlorine gas.

That is a mistake. Perchlorate desintegrates in several steps to chloride, for example potassium or sodium chloride (KCl or NaCl) which will not give alkali metal and chlorine at all - not at 1000 degree C.

For the same reason, a solid fuel booster does not produce a greenish smoke streak.

Interestingly, in a chloride rich layer with trace amounts of oxygen (mayby especial atomic oxygen as a result of photo dissociation of water) perchlorat is the most stable species and develops from hypochlorite (ClO-) or chlorite (ClO2-) via chlorate (ClO3-) by disproportionation. (foprmig the next higher "chloride-oxide" and chloride. The motor for this the tetrahedonal structur and the energetical metastable state of the perchlorat as a result of chemical bonds given to all eight chloride-electrons. Another possibility would be peroxo-disulphate as a relatively stable species of the layer is sulphate rich; nitrates are more difficult, because there is only one stable anorganic nitrogen rich starting material: ammonia (NH4+), mayby in form of ammonia carbonate or -carbamate.

Posted by: Ipparchus Aug 19 2008, 07:59 AM

Have they aquired a soil sample for TEGA oven 7? How many watts has Phoenix available right now and how many it needs just to stay alive (in hibernation mode)?

 

Posted by: jmknapp Aug 19 2008, 10:56 AM

QUOTE (Harkeppler @ Aug 15 2008, 06:22 AM) *
Perchlorate desintegrates in several steps to chloride, for example potassium or sodium chloride (KCl or NaCl) which will not give alkali metal and chlorine at all - not at 1000 degree C.

For the same reason, a solid fuel booster does not produce a greenish smoke streak.

Interestingly, in a chloride rich layer with trace amounts of oxygen (mayby especial atomic oxygen as a result of photo dissociation of water) perchlorat is the most stable species and develops from hypochlorite (ClO-) or chlorite (ClO2-) via chlorate (ClO3-) by disproportionation.


Thanks for the chemistry insight--so the results so far may be consistent after all.

Here's a http://gsa.confex.com/gsa/2005AM/finalprogram/abstract_96538.htm to natural formation of perchlorate from cloride:

QUOTE
PHOTOOXIDATION OF CHLORIDE TO PERCHLORATE IN THE PRESENCE OF TITANIUM DIOXIDE AND DESERT SOILS

Perchlorate has been observed in playa soils in areas of the western United States, in nitrate deposits from northern Chile, and has also been observed at low concentrations in surface and groundwater in the southwestern United States, distant from industrial sources. Studies were conducted to determine if perchlorate could be formed when dry chloride salts were exposed to ultraviolet light (sunlight or ultraviolet lamps) in the presence of titanium dioxide and soils. Production of perchlorate was observed, and varied with the conditions used; for example, 59 days of UV-B irradiation of 8 mg of chloride in the presence of 200 mg of titanium dioxide on a petri dish resulted in the production of 260 ng/plate of perchlorate. In the presence of thin layers (ca. 3 mm) of desert soil collected from Death Valley, Calif. and exposed to sunlight for 3 months, perchlorate was observed at concentrations up to 45 ng/gm. Additionally, a limited number of desert soils were analyzed by ion chromatography to determine if perchlorate was present. Concentrations varied from non-detectable to 63 ng/gm of soil. Because titanium dioxide, and to a lesser extent, desert soils, have previously been shown to generate hydroxyl radical under irradiation, these results suggest a natural source of perchlorate in the arid regions of the southwestern United States.


Also http://gsa.confex.com/gsa/2005AM/finalprogram/abstract_91616.htm:

QUOTE
Formation of natural perchlorate under strongly oxidizing conditions is possible through evaporation and production of ozone during electrical storms. These processes occur in northern New Mexico and may generate low concentrations of perchlorate during early stages of the hydrological cycle.


Posted by: Ipparchus Aug 20 2008, 07:50 AM

Doug, you told me the ceramic blank is on the deck, but I can`t find in the photos! can you show me a photo in which I can clearly see it (please make a circle around it, so I can see exactly where it is). What do you mean when you say "they will have to get it with the rasp". The rasp is needed to work the ceramic blank? Another think I`d like to learn is how many watts has Phoenix available right now and how many it needs just to stay alive (in hibernation mode)? (Sorry for my innumerous questions!!!).

Posted by: jamescanvin Aug 20 2008, 08:08 AM

We talked about the ceramic blank http://www.unmannedspaceflight.com/index.php?s=&showtopic=5249&view=findpost&p=120184, with close up photo

On the deck it is the white block that is in the area where the arm was stowed (and was therefore under the bio-barrier). About halfway between the camera and TEGA.

EDIT:


Posted by: Ipparchus Aug 20 2008, 08:25 AM

Thank you very much my friend! but why Doug told me they`ll have to use the rasp to work? I think the ceramic blank should be on the TEGA, why it isn`t? can it work being away?

 

Posted by: Reckless Aug 20 2008, 08:55 AM

It had to be under the bio-barrier with the RA to protect it from contamination until after landing (the TEGA ovens are sealed anyway) and the block is hard and has to be rasped to get the right sized particles and perhaps to clean the rasp and get to uncontaminated ceramic inside.
This is just off the top of my head it's awhile since I read about the ceramic block, hope this is of some help

Roy

Posted by: centsworth_II Aug 20 2008, 01:10 PM

QUOTE (Ipparchus @ Aug 20 2008, 04:25 AM) *
I think the ceramic blank should be on the TEGA, why it isn`t? can it work being away?

The ceramic blank works like this:
A sample is collected from it just as a sample would be collected from the Martian surface and then transported by the scoop to TEGA and analyzed. So just as they might use the rasp to scrape up samples of ice for testing, they would use the rasp to scrape up a sample from the ceramic block. Just as the scoop dumps the ice sample into TEGA, it would dump the scraped up blank sample into TEGA. The entire ceramic block is not analysed as the blank, just the small sample that is scraped from it.

Posted by: remcook Aug 20 2008, 01:30 PM

so how do they prevent contamination from soil left in the scoop?

Posted by: centsworth_II Aug 20 2008, 01:57 PM

QUOTE (remcook @ Aug 20 2008, 08:30 AM) *
so how do they prevent contamination from soil left in the scoop?

I guess if they see a 99% drop in organic signal, the remaining 1% might be attributable to residue in the scoop. But larger signals would not be. There is also the issue of contamination by Martian dust settled on the surface of the blank.

I think that the main purpose of the blank is not to check for contamination at all. The main purpose is to provide a controlled, organics free sample to ensure that TEGA does not signal the presence of organics when there are none present. It's mainly an instrument check, not a contamination check. IMO

Although I would think that not detecting organics in the surface samples would provide the same control.

Posted by: peter59 Aug 21 2008, 09:03 AM

Delivery of sample to TEGA oven #7 (successful or not).



 

Posted by: Ipparchus Aug 21 2008, 09:44 AM

I think it`s unsuccessful. I can`t see any soil on the TEGA oven #7.

Posted by: imipak Aug 21 2008, 07:52 PM

Looks like a direct hit to me; there's plenty of sample on the, um, "lintel" areas above the doors. None showing on the screen, but they've a lot more practice with the sprinkle technique, and with vibrating the sample material down into the instrument, than was the case with the first couple of ovens.

Posted by: centsworth_II Aug 21 2008, 09:27 PM

QUOTE (Ipparchus @ Aug 21 2008, 05:44 AM) *
I think it`s unsuccessful. I can`t see any soil on the TEGA oven #7.

The optimistic view would be that all the soil that dropped on the screen went straight through to the oven.

Posted by: 1101001 Aug 21 2008, 11:56 PM

http://www.jpl.nasa.gov/news/phoenix/release.php?ArticleID=1835

QUOTE
Data received from Phoenix early Thursday confirmed that the arm had delivered some of that sample through the doors of cell 7 on the lander's Thermal and Evolved Gas Analyzer (TEGA) and that enough material passed through a screen and down a funnel to nearly fill the cell's tiny oven. The Phoenix team prepared commands Thursday to have TEGA close the oven and begin heating the sample to low temperature (35 degrees Celsius, or 95 degrees Fahrenheit).


Cook it.

Posted by: 1101001 Aug 25 2008, 08:02 PM

Anyone know why they did a TEGA oven #0 delivery pose on Sol 89? They did a delivery on or about Sol 64; I think it was Witch's Hat -- the sample with just a bit of ice in it.

Sol 64 oven #0 delivery pose:
http://phoenix.lpl.arizona.edu/images.php?gID=16816&cID=189

Sol 89 oven #0 delivery pose:
http://phoenix.lpl.arizona.edu/images.php?gID=24842&cID=247

Posted by: akuo Aug 30 2008, 05:16 PM

Looks like a delivery practise run over oven 0 was performed tosol, as described by http://planetary.org/blog/article/00001623/. Looks to me some stuff fell through to the (closed) oven. But was it an icey sample? I can't see ice rasping being perfomed in tosol's images.

Posted by: 1101001 Sep 1 2008, 05:08 PM

http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=265

TEGA Oven #1 opened: one door fully, one door partially.
http://phoenix.lpl.arizona.edu/images.php?gID=26184&cID=265

And scoop also imaged near open door. Can't tell if it's a delivery or a pose for practice.

Edit: With later images, it appears the scoop of soil went to MECA WCL, probably from Stone Soup. When the scoop was near TEGA, I'm pretty sure it was empty. It was later afternoon, so wouldn't have been a cold time for an icy TEGA delivery anyway.

Posted by: akuo Sep 1 2008, 07:46 PM

Very nice to see a fully opened door smile.gif.

Posted by: peter59 Sep 4 2008, 03:41 PM

Fresh ice exposed in the trench “Dodo-Goldilock”. Preparation for collecting sample of ice for TEGA oven #1 ?


Posted by: stevesliva Sep 4 2008, 05:50 PM

Nice! Let's hope so.

Posted by: 1101001 Sep 18 2008, 11:44 PM

http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=301 document a TEGA #1 delivery of a (hopefully icy) sample from Snow White trench. So far there aren't enough images to tell the whole story. All are probably post-delivery, in which an empty scoop is a good sign -- if it held a sample earlier.

Posted by: fredk Sep 20 2008, 05:48 PM

The latest TEGA ice sample got stuck at the screen and didn't make it into the oven, according to Smith at about 22:20 into yesterday's NPR interview (22MB file):

http://podcastdownload.npr.org/anon.npr-podcasts/podcast/510221/94836803/npr_94836803.mp3

Posted by: centsworth_II Sep 20 2008, 06:03 PM


Posted by: dvandorn Sep 20 2008, 06:45 PM

I don't know whether to laugh, cry or wonder whether or not there ought to be some kind of investigation into the (what appears to be) serious underperformance of the TEGA itself and the sample delivery system associated with it.

Was it actually not possible to anticipate the clumpiness and stickiness of ice-rich soil? Or was the possibility just not considered?

I'm not really criticizing, I'm more in wonderment... it seems an awful lot of time, energy and money to spend to deliver a system to the surface of Mars, sitting directly over Martian ice, which seems incapable of running analyses on said ice...

huh.gif

-the other Doug

Posted by: centsworth_II Sep 20 2008, 06:55 PM

QUOTE (dvandorn @ Sep 20 2008, 01:45 PM) *
Was it actually not possible to anticipate the clumpiness and stickiness of ice-rich soil?

It's not clear to me that the ice rich stuff is any stickier than the dry stuff. And as far as I know, the stickiness of the dry stuff remains a complete mystery. It's hard to anticipate mysteries.

Posted by: 1101001 Sep 20 2008, 07:45 PM

Anyone who thinks they know why the soil is sticky, is welcome to suggest their recipe for a simulant soil mimicking the properties of Green Valley soil. So far the science team hasn't put together a recipe that acts the same.

Posted by: ElkGroveDan Sep 20 2008, 08:02 PM

If we are talking about creating a soil that mimics the Martian polar soil, but at STP for testing here on earth, I'd suggest making a damp sand, but use a wetting agent slightly heavier than water such as glycerin.

Posted by: ConyHigh Sep 20 2008, 08:28 PM

QUOTE (dvandorn @ Sep 20 2008, 11:45 AM) *
I don't know whether to laugh, cry or wonder whether or not there ought to be some kind of investigation into the (what appears to be) serious underperformance of the TEGA itself and the sample delivery system associated with it.

Was it actually not possible to anticipate the clumpiness and stickiness of ice-rich soil? Or was the possibility just not considered?

I'm not really criticizing, I'm more in wonderment... it seems an awful lot of time, energy and money to spend to deliver a system to the surface of Mars, sitting directly over Martian ice, which seems incapable of running analyses on said ice...

huh.gif

-the other Doug


As soon as the US Congress straightens out the economy, they can tackle the sticky Martian sol.
Seems to me if we knew the answers, we shouldn't have gone there in the first place. This gives the next mission something to work on.

Posted by: Mariner9 Sep 20 2008, 08:36 PM

QUOTE (ElkGroveDan @ Sep 20 2008, 01:02 PM) *
If we are talking about creating a soil that mimics the Martian polar soil, but at STP for testing here on earth, I'd suggest making a damp sand, but use a wetting agent slightly heavier than water such as glycerin.



And then put the soil in a chamber which can simulate the Martian atmosphere and the temperature of the north polar region. Then put the Engineering mockup of the lander in there, let it cool down for a few hours (more likely days) and then see what happens when you start scooping up the soil.

Ouch.

I really sympathize with the engineers and program scientists.... figuring out all the possible variations of Martian soils, and how they would act in an actual Martian environment, must be really difficult.

Posted by: ElkGroveDan Sep 20 2008, 09:43 PM

QUOTE (Mariner9 @ Sep 20 2008, 01:36 PM) *
And then put the soil in a chamber which can simulate the Martian atmosphere and the temperature of the north polar region. Then put the Engineering mockup of the lander in there, let it cool down for a few hours (more likely days) and then see what happens when you start scooping up the soil.


Actually no. I wasn't suggesting that the cold, low pressure, low gravity, martian soil was laced with glycerin. I was suggesting a method of making the soil sticky to MIMIC martian conditions under Standard Temperature and Pressure, with the goal of testing how to manipulate that soil.

Posted by: JRehling Sep 20 2008, 10:13 PM

QUOTE (ConyHigh @ Sep 20 2008, 01:28 PM) *
Seems to me if we knew the answers, we shouldn't have gone there in the first place.


Right, but there's a difference between having the scientific facts in hand and having engineered for tolerance of varying outcomes. You wouldn't have to know the precise mechanical properties of martian soil to design a system that would have worked with a broader set of possibilities.

It looks to me like the arm has an A+ shoulder, an A+ elbow, an A+ wrist and dead fingers.

The ground operations of Phoenix are approximately 85% complete (could be 99% -- we're at the mercy of happenstance), and still no icy sample. Whether or not blame is merited (aside from the balky oven doors) is a topic I have no passion for, but the outcome so far is extremely disappointing to me. And as far as getting it right next time goes, remember that THIS was the re-fly of a mission that would have landed 9 years ago. It was bad enough to go 400 million km and lose MPL in the last 100 km, but it's just as frustrating to go 400 million km on the second try and end up with ice 5 cm from the oven.

Phoenix was successful enough in accomplishing some of the other goals that it makes the idea of a THIRD try even more painful. And there won't be the same legacy hardware in the closet to keep the cost down next time.

As I'd said before, with something like MPL all of the pain comes in one evening, but with this, it's been like watching a sports team lose and taking months to do it. It's been agonizing.

Posted by: centsworth_II Sep 20 2008, 10:37 PM

QUOTE (JRehling @ Sep 20 2008, 05:13 PM) *
...but with this, it's been like watching a sports team lose and taking months to do it. It's been agonizing.

Astounding that you compare Phoenix to a losing sports team! The team has WON. It just hasn't gotten as many home runs as you would have liked. I have my own list of what could be done better on a second try. But this is a first try.

Even now, we don't know why the soil is so sticky. We don't know if the icy and ice-free soils are sticky for the same reasons.

Posted by: Shaka Sep 20 2008, 11:31 PM

Have any previous Mars landers given a hint of this degree of ...er...'clumpiness' (Yes it's ugly, but it's the only word I could conjure up on the spur of the moment.)? I certainly haven't noticed it from the MER. It's perhaps unfair to have expected the TEGA designers to allow for it.

Posted by: ConyHigh Sep 20 2008, 11:35 PM


but with this, it's been like watching a sports team lose and taking months to do it. It's been agonizing.
[/quote]

Hrumpf.
NOT losers. Not by a long shot.
mad.gif

Posted by: JRehling Sep 21 2008, 12:46 AM

I've seen people try to rate the success/failure of missions that were partial successes, and never saw any good come out of those discussions.

But the ice is why the high latitudes were targeted and the tradeoffs made to land at 68N. The mission success criteria drawn up before the mission stipulate that TEGA would be used to profile H2O abundances using at least two (=partial mission success) or three (= full mission success) different samples. Relative to the possibilities that Mars itself makes possible (eg, the ice is within reach, not 40cm down), even those criteria are modest and the pace of operations has fallen behind from the first weeks and remains behind as the remaining time shrinks.

If you look at the higher-level objectives, the importance of the D:H ratios are clear. And we have samples that have that information inside them just centimeters from the detectors that could measure it. I find that frustrating, and nothing else the mission does makes up for that.

Barry Goldstein (one of the operations managers at JPL) summarized things last week as "We're now at the point ... where we have to struggle to do each of the things we need to do." I think that word "struggle" captures the feeling I've had since the electronics problems were reported and the doors started jamming.

This IS the re-fly (hence the name "Phoenix"). This is the mission that when the competition came around had the advantage of reusing hardware from the cancelled 2001 mission. I can't think of a time since Ranger and Surveyor that an objective was met by flying a third mission where two before had fallen short.

Posted by: Wildthing Sep 21 2008, 12:52 AM

QUOTE (JRehling @ Sep 20 2008, 06:13 PM) *
, but the outcome so far is extremely disappointing to me. , but with this, it's been like watching a sports team lose and taking months to do it. It's been agonizing.


I have to agree with you on this...... I've lirked on this site for ages.....there are some very bright and talented people posting here...frankly a bit too tight for my liking but the only problem I have with that is that some of you "experts" are reluctant to call things the way "Joe Ordinary" would see it.

Who's Joe ?...why, that's me.....an ordinary person who has been following the Space program since the manned Mercury days....that's my credentials...maybe not much but that's all I got..

So why am I disappointed ??...because this was the mission that was going to get a real honest to gooodness taste of Martion H2O...it was there...we could see it viia instruments from Martian orbit but to get a significan sample tested, we need to be on Martian dirt.

Phoenix has accomplished some amazing things but without a significant ice sample and an analysis report showing that H20, something an "ordinary" person following this mission can undertand, I can't call this mission a success....

It's going to be a long time before another lander gets a crack at this soil...with that in mind, the soil/ice capture design should have been over engineered to ensure that any sample would be delivered to the testing instruments under any condition...

Just "Joe Ordinary's" $0.02....

Posted by: Aussie Sep 21 2008, 01:25 AM

I feel that solving the underlying cause of the sample 'stickiness' is just as important than getting a permafrost sample to the oven. The adhesive quality doesn't seem to be a function of ice as the sample from stone soup showed greater adhesion than the permafrost scrapings. With the lack of H2O from the probe results this seems to rule out H2O as a (major) contributing factor for the clumping.

Regardless, this is not an underperformance of the system. The screen is there to stop the introduction of large particles to the oven entrance where they could jam, so the clumping samples could not have got to the oven in any case. There is still the possibility that the sample will break down as the first one did and penetrate the screen in a few days time - so all is not yet lost.

I'm not sure why trying to make a soil analogue is important. Unlike the rovers where they were trying to experiment with extraction techniques for the bogged vehicle Phoenix is on a very short timescale before the arm usage must be restricted or terminated. A mixture of non representative substances may make a reasonable analogue for the initial 'stickiness', but it would almost certainly not have the same breakdown characteristics over time - particularly when I don't believe we have a clue what is causing the adhesion in the first place. The answer is probably there in the TEGA and MECA results. wink.gif

Posted by: JRehling Sep 21 2008, 02:18 AM

QUOTE (Aussie @ Sep 20 2008, 06:25 PM) *
I feel that solving the underlying cause of the sample 'stickiness' is just as important than getting a permafrost sample to the oven. The adhesive quality doesn't seem to be a function of ice as the sample from stone soup showed greater adhesion than the permafrost scrapings.


I've walked through some kinds of mud and come away with clean soles -- the mud adheres to itself. Other kinds seems to suck the shoe off my foot. Is there a science that studies this? There certainly *could* be, but I don't know if anyone actually publishes on it. What would you even call it -- centigeology?

This reminds me of lots of phenomena that take place with ice freezing that on Earth might be more the subjects poets and fishermen study rather than scientists. But on Mars, the equivalent phenomena take on engineering importance, and arguably scientific importance.

But the D:H ratio is of fundamental importance. I'd say there are three things of utmost interest that Phoenix was looking for:

1) The dynamics and history of H2O at this latitude.
2) The possibility of organics in that ice.
3) The identity of the Viking oxidant.

So far, we have apparent success at #3 and we may get good data on #2 out of the data we already have, but #1 probably cannot be done with the trace amounts found in the earlier sample. So the major objectives of this mission will have a very large hole at the top if something doesn't break our way soon, with at most about 15% of the active surface operations to go.

Posted by: centsworth_II Sep 21 2008, 02:36 AM

QUOTE (Wildthing @ Sep 20 2008, 07:52 PM) *
Just "Joe Ordinary's" $0.02....

I also have no special qualifications other than a general interest in science and I think the more interesting aspect of the Phoenix mission is a characterization of the soil chemistry. Witness the stir caused by the clumsy release of the perchlorate discovery. Can you really imagine that a similar popular interest could be stirred up by any revelation involving D:H ratios? I realize D:H is important to understanding transport of H2O on today's Mars and something of the history of H2O on Mars. But, really, ho hum. Try to get Joe Ordinary (you excepted) really interested in that. Give me the here and now soil chemistry for real excitement. Phoenix will do that to a great extent.

I too will be frustrated and disappointed if we can't get a D:H ratio. But I will not let that blind me to all the wonderful new things that Phoenix will teach us about Mars.

Posted by: centsworth_II Sep 21 2008, 03:07 AM

QUOTE (JRehling @ Sep 20 2008, 09:18 PM) *
I've seen people try to rate the success/failure of missions that were partial successes, and never saw any good come out of those discussions.

Well you seem to have done a fairly good job of it yourself (see below). smile.gif

QUOTE (JRehling @ Sep 20 2008, 09:18 PM) *
...I'd say there are three things of utmost interest that Phoenix was looking for:

1) The dynamics and history of H2O at this latitude.
2) The possibility of organics in that ice.
3) The identity of the Viking oxidant.

So far, we have apparent success at #3 and we may get good data on #2 out of the data we already have, but #1 probably cannot be done with the trace amounts found in the earlier sample.

According to the http://phoenix.lpl.arizona.edu/mission.php, "Phoenix is designed to study the history of water and habitability potential in the Martian arctic's ice-rich soil."

I would say that "study the habitability potential" is the more interesting aspect of the mission to the public. This part of the mission seems to have been largely successful. Don't let your disappointment ruin a chance to share in the excitement.

Posted by: centsworth_II Sep 21 2008, 03:15 AM

QUOTE (Aussie @ Sep 20 2008, 08:25 PM) *
...There is still the possibility that the sample will break down as the first one did and penetrate the screen in a few days time - so all is not yet lost....

Unfortunately the breakdown would probably be accompanied by a loss of ice. Still no H20 analysis.

QUOTE (Aussie @ Sep 20 2008, 08:25 PM) *
I feel that solving the underlying cause of the sample 'stickiness' is just as important than getting a permafrost sample to the oven.... The answer is probably there in the TEGA and MECA results.

It will be interesting to see what there is to be learned from all the data that Phoenix has collected during its full life on mars. I suspect it will be a lot. We will have to wait months and perhaps years for the data to be analyzed and the papers written.

Posted by: ConyHigh Sep 21 2008, 03:17 AM

QUOTE (centsworth_II @ Sep 20 2008, 08:15 PM) *
Unfortunately the breakdown would probably be accompanied by a loss of ice. Still no H20 analysis.


It will be interesting to see what there is to be learned from all the data that Phoenix has collected during its full life on mars. I suspect it will be a lot. We will have to wait months and perhaps years for the data to be analyzed and the papers written.


Would expect some of the data to be discussed at AGU in December.

Posted by: JRehling Sep 21 2008, 03:40 AM

QUOTE (centsworth_II @ Sep 20 2008, 08:07 PM) *
Well you seem to have done a fairly good job of [rating the success]


I cited the mission's own official priorities -- both the programmatic list of success criteria and then, although I paraphrased, their own explanation of the science objectives, in the order they mention them. You or I could have personal objectives for the mission, and it's those I wouldn't see much point in contrasting at length (if we have them), but their own criteria are right to the point.

I don't think it'll be helpful to try to get to the bottom of whether or not my excitement or lack thereof is of the right degree.

Posted by: BrianL Sep 21 2008, 04:58 AM

Perhaps there is a technical reason why this couldn't be done, but...

Why didn't they just put a heating element in the scoop so that the ice scrapings could melt there and then be poured as a liquid into the TEGA chamber?

Posted by: centsworth_II Sep 21 2008, 05:36 AM

QUOTE (BrianL @ Sep 20 2008, 11:58 PM) *
...the ice scrapings could melt there and then be poured as a liquid into the TEGA chamber?

I wonder what ice:soil ratio in the scrapings is. If you got any liquid water at all after accounting for sublimation before reaching the melting point and boiling off after, it would be absorbed by any soil present. You might just end up with mud stuck in the scoop.

Posted by: JRehling Sep 21 2008, 05:40 AM

I don't think there is a liquid phase of water at this pressure. If you heated it, it would turn directly into a gas, and you'd get nothing in the oven. At least, the pressure is very near the triple point, so you wouldn't want to count on the [considerable!] diurnal cycles in pressure to work in your favor.

In hindsight, it's the passive dropping/dumping that can't be counted on. If there were a "fist" on the arm that ground and pounded and jammed the sample into place, that would do the trick. Presumably grinding and extrusion of the sample could minimize sublimation if the oven were sealed promptly.

Posted by: Aussie Sep 21 2008, 08:30 AM


That is why we should call it a permafrost sample rather than ice sample. I wonder just how much of a H2O ice content is there in the permafrost?


Posted by: peter59 Sep 21 2008, 12:32 PM

Next failure - TEGA Oven #2

http://phoenix.lpl.arizona.edu/images/gallery/lg_33892.jpg
sad.gif

Posted by: Paul Fjeld Sep 21 2008, 01:14 PM

QUOTE (JRehling @ Sep 20 2008, 10:40 PM) *
I cited the mission's own official priorities -- both the programmatic list of success criteria and then, although I paraphrased, their own explanation of the science objectives, in the order they mention them.

I think your approach is the right one to assess the success of Phoenix.

It would be great if there was some way to tell the overall frustration level amongst the science team at the end of the mission and if in fact they would be kicking themselves for making certain assumptions rather than others about the nature of the soil/ice they would be sampling. The TEGA doors are a partial engineering mistake, but it's not clear that that's what's costing them. The 'broken fingers' (nice one) are only broken when it comes to delivering the ice-rich sample, otherwise its been a champ Swiss Army knife.

For me it comes down to 'poor engineering guess' or 'Martian Mystery.' If the former, the whole mission is a success (but with an annoying little fly buzzing around), if the latter, even without the ice it's a great success. Get the ice ratio stuff and it's Heroic.

Posted by: Wildthing Sep 21 2008, 01:30 PM

QUOTE (JRehling @ Sep 21 2008, 01:40 AM) *
In hindsight, it's the passive dropping/dumping that can't be counted on. If there were a "fist" on the arm that ground and pounded and jammed the sample into place, that would do the trick. Presumably grinding and extrusion of the sample could minimize sublimation if the oven were sealed promptly.



At this point in the mission, why not "rasp till ya' drop"....there doesn't seem to be much problem in collecting an ice sample via the rasp...why not run the rasp over the hard ice areas until the scoop is full, hoping that a full scoop will have enough weight to overcome the clumpiness/stickiness of th soil and fall into a collector ??...I realize there is some danger in burning out the rasp motor but at this stage, so what ???

Posted by: alan Sep 21 2008, 04:06 PM

Maybe the soil will get less sticky once it gets colder say after there is a significant period without sunlight during a sol. Doing the scope and dump overnight then may be more successful.

Posted by: centsworth_II Sep 21 2008, 04:30 PM

QUOTE (Wildthing @ Sep 21 2008, 08:30 AM) *
...why not run the rasp over the hard ice areas until the scoop is full, hoping that a full scoop will have enough weight to overcome the clumpiness/stickiness of the soil and fall into a collector ??...

The worst thing that can be done with this sticky soil/ice is to dump it all at once. This did not work in the first TEGA delivery. Hense the development of the "sprinkle" delivery method. The "dump in a clump" method has even clogged the wide-mouthed MECA.


Posted by: centsworth_II Sep 21 2008, 04:36 PM

QUOTE (Paul Fjeld @ Sep 21 2008, 08:14 AM) *
The 'broken fingers' (nice one) are only broken when it comes to delivering the ice-rich sample, otherwise its been a champ Swiss Army knife.

So why is there a clogged MECA funnel? I assume they didn't use the sprinkle method developed for TEGA deliveries. If they had, I don't think the MECA delivery would have fouled.

Posted by: 1101001 Sep 21 2008, 04:50 PM

QUOTE (Wildthing @ Sep 21 2008, 06:30 AM) *
At this point in the mission, why not "rasp till ya' drop"....there doesn't seem to be much problem in collecting an ice sample via the rasp...why not run the rasp over the hard ice areas until the scoop is full, hoping that a full scoop will have enough weight to overcome the clumpiness/stickiness of th soil and fall into a collector


I recall they were suspicious that more rasping caused more stickiness, because the rasp motor lies right behind the rear wall of the scoop, and more heat from the motor -- like more heat from the Sun -- made the stickiness worse.

http://news.bbc.co.uk/2/hi/science/nature/7528950.stm

QUOTE
The revised plan involves cutting the amount of time spent using the rasp, to avoid heating the sample, and shaking the scoop more when delivering it to the oven.

Posted by: 1101001 Sep 22 2008, 03:56 AM

QUOTE (centsworth_II @ Sep 21 2008, 09:36 AM) *
So why is there a clogged MECA funnel? I assume they didn't use the sprinkle method developed for TEGA deliveries. If they had, I don't think the MECA delivery would have fouled.


I wouldn't assume that. MECA WCL #3 got two deliveries, because the first failed. They were sol 96, Golden Goose 2, and sol 102, Golden Goose 3.

I think sprinkle has become the standard for delivery to both TEGA and MECA WCL. I'd expect sprinkle was used for the initial attempt to deliver a sample to MECA WCL #3.

http://blogs.jpl.nasa.gov/?p=4:

QUOTE
[Describing the learning curve:] We tried three methods: de-lumping, sprinkling and agitation.

[...] The sprinkle and agitation methods have been routinely adopted for sample delivery.

The neat consequence of this is that it solves what had always been our worry about how to deliver the same sample to each instrument for comparison of science results. The sprinkle delivery method enables us to put a large sample into the scoop and deliver part of it to MECA microscopy, part to MECA wet chemistry and part to the TEGA instrument. Same sample problem: solved!!


The first delivery to WCL #3 didn't succeed. If they used the routine sprinkle and it still failed, then they might have changed method and attempted a more forceful large dump for the second, also failed, delivery attempt, yielding the mound of soil we now see on the cell mouth.

Posted by: Ipparchus Sep 23 2008, 08:40 AM

From which trenches do you think the next TEGA samples are going to be? what will they do with the unsuccessful TEGA-1 Snow White sample? they will leave it as it is or they`ll try to fill it with more sample?


 

Posted by: peter59 Sep 26 2008, 04:35 PM

Next TEGA oven doors had clearly failed to open.

Sol 115 - TEGA oven door #2



Sol 120 - TEGA oven door #6


Posted by: 1101001 Sep 26 2008, 05:08 PM

QUOTE (peter59 @ Sep 26 2008, 09:35 AM) *
Next TEGA oven doors had clearly failed to open.


Failed to open fully, right?

Oven number 5 I think was the very first where both doors opened partially, but it was successfully delivered to anyway. (http://www.planetary.org/blog/article/00001593/)

Posted by: 1101001 Sep 26 2008, 05:10 PM

QUOTE (Ipparchus @ Sep 23 2008, 01:40 AM) *
From which trenches do you think the next TEGA samples are going to be? what will they do with the unsuccessful TEGA-1 Snow White sample? they will leave it as it is or they`ll try to fill it with more sample?


I think http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=315 documents a second delivery from Snow White to TEGA #1.

Small sample in the scoop (0749 local time) and the scoop over #1 (0757) and the scoop empty (0825):
http://phoenix.lpl.arizona.edu/images.php?gID=35510&cID=315 http://phoenix.lpl.arizona.edu/images.php?gID=35304&cID=315 http://phoenix.lpl.arizona.edu/images.php?gID=35311&cID=315

Before (0717) and after (0750), trench probably Snow White:
http://phoenix.lpl.arizona.edu/images.php?gID=35404&cID=315 http://phoenix.lpl.arizona.edu/images.php?gID=35405&cID=315

Posted by: peter59 Sep 26 2008, 05:45 PM

QUOTE (1101001 @ Sep 26 2008, 05:10 PM) *
I think http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=315 documents a second delivery from Snow White to TEGA #1.

No doubt, it's sample of ice.

Posted by: 1101001 Sep 28 2008, 06:13 AM

Possible TEGA, maybe oven #2, delivery on sol 122.

http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=320

Interesting white stuff, scoop before (1028 local time), TEGA (1041), scoop after (1047):
http://phoenix.lpl.arizona.edu/images.php?gID=35874&cID=320 http://phoenix.lpl.arizona.edu/images.php?gID=35862&cID=320 http://phoenix.lpl.arizona.edu/images.php?gID=35880&cID=320

Posted by: akuo Sep 28 2008, 06:19 AM

Whoa. Where was all that ice scooped from? No sample source SSI images visible yet.

Posted by: djellison Sep 28 2008, 09:36 AM

That's going to be the OFB surely?

Posted by: slinted Sep 28 2008, 09:36 AM

Here's some RAC color of the scoop. Hopefully, some made it into the oven. Judging from the post-delivery images, it looks like the darker material stayed in the scoop while the bright stuff mostly fell out.

http://www.lyle.org/~markoff/processed/RS122EFF907031277_1E220MB.jpg
http://www.lyle.org/~markoff/processed/RS122EFF907031277_1E220MB.jpg

http://www.lyle.org/~markoff/processed/RS122EFF907033077_1E230MB.jpg
http://www.lyle.org/~markoff/processed/RS122EFF907033077_1E230MB.jpg

http://www.lyle.org/~markoff/processed/RS122EFF907034057_1E260MB.jpg
http://www.lyle.org/~markoff/processed/RS122EFF907033077_1E230MB.jpg

Posted by: ConyHigh Sep 28 2008, 02:07 PM

QUOTE (djellison @ Sep 28 2008, 02:36 AM) *
That's going to be the OFB surely?

Most likely you are correct.
Maine is bracing for a big blow today/tonight -- wish us well.

Posted by: peter59 Sep 28 2008, 06:20 PM

Sprinkling in action. Away out. mad.gif


Posted by: fredk Sep 28 2008, 07:17 PM

Good catch, Peter. I'd been wondering how much of an effect the wind has on their sprinkling efforts. They're most interested in the smallest grains which can pass through the screens, but the smallest grains are most affected by the wind. Do they take wind into account in placing the scoop above the ovens?

That exposure is 1/40th of a second if I read the header correctly, which says those particles are moving pretty fast...

Posted by: peter59 Sep 28 2008, 07:49 PM

This image indicates that the influence of wind must be very significant.


Posted by: imipak Sep 28 2008, 08:24 PM

We can see some material missing the target; that doesn't necessarily mean it all missed. Also, two images of falling material presumably indicates a deliberate effort to catch it in the act, so it's success on that count; and if the strength of the wind effect was unexpected, that's a win as well. (Lemonade, anyone?)

Posted by: Aussie Sep 29 2008, 04:45 AM

QUOTE (peter59 @ Sep 28 2008, 07:49 PM) *
This image indicates that the influence of wind must be very significant.


Maybe. But it could also be an image taken when the scoop stopped at the end of a left to right swing while vibrating. The material in the scoop funnel seems to be concentrated to the right of the funnel which would imply movement of the particles through inertia when the scoop stopped, with the particles that fell out moving to the right. Inertia rather than wind energy. The CSA Mars Weather Report hasn't been updated since Sol 99 so we don't know what the wind was at ground level. But from the Sol 122 TEGA (1041) image the material ended up on the left of the oven lid as well so delivery would have been on target.

Where was this sample from? Ice or salts?

Posted by: 1101001 Sep 29 2008, 04:59 AM

QUOTE (Aussie @ Sep 28 2008, 09:45 PM) *
Where was this sample from? Ice or salts?


Smart money's on organic-free blank. It's the whitest thing around.

The wind was blowing when the delivery was attempted, if you believe the telltale. It was hopping around 10:30 local time that sol.

http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=320

For instance, at 1033 local:
http://phoenix.lpl.arizona.edu/images.php?gID=36070&cID=320

Posted by: Shaka Sep 29 2008, 05:19 AM

mad.gif Aw, hell!.....and I was gonna make a snowman!

Posted by: 1101001 Sep 29 2008, 11:47 AM

http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=321

Source of the white stuff, the Organic-Free Blank:
http://phoenix.lpl.arizona.edu/images.php?gID=36265&cID=321


Posted by: ElkGroveDan Sep 29 2008, 01:45 PM

The Organic Free Blank (OFB)

http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1067.pdf (top of page 2)

QUOTE
The Phoenix OFB will be used only if organic C is detected on Mars by TEGA. The OFB will then be sampled and analyzed, and results will be compared to the organic signatures released by the Martian sample. After OFB analysis, a TEGA run will be conducted on a second sample of the putative organic-containing material to validate the first analysis. High concentra-tions of organic molecules and possibly organic frag-mentation patterns not in the OFB will also contribute to a credible positive identification of organic mole-cules indigenous to Mars. The high total carbon con-tent in the OFB FM (1.6 μg C g-1 of sample) may re-quire that the total C content in the Martian materials substantially exceed this number, perhaps as much as 10 μg C g-1 of sample before a positive detection of organic molecules on Mars is credible.

MARS 2007 PHOENIX SCOUT MISSION ORGANIC FREE BLANK: METHOD TO DISTINQUISH MARS ORGANICS FROM TERRESTRIAL ORGANICS. [/b]
D.W. Ming1, R.V. Morris1, R. Woida2, B. Sutter3, H.V. Lauer3, C. Shinohara2, D.C. Golden3, W.V. Boynton2, R.E. Arvidson4, R.L. Stewart5, L.K. Tamppari6, M. Gross6, P. Smith2, and the Phoenix Science Team. 1ARES, NASA Johnson Space Center, Mail Code KX, Houston, TX 77058 (douglas.w.ming@nasa.gov), 2Lunar & Planetary Laboratory, University of Arizona, Tucson, AZ, 3Jacobs Engineering, ESCG, Houston, TX, 4Dept. Earth and Planetary Sciences, Washington University, St. Louis, MO, 5Corning Incorporated, Corning, NY, 6Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA.

Posted by: ConyHigh Sep 29 2008, 02:10 PM

QUOTE (Aussie @ Sep 28 2008, 09:45 PM) *
Maybe. But it could also be an image taken when the scoop stopped at the end of a left to right swing while vibrating. The material in the scoop funnel seems to be concentrated to the right of the funnel which would imply movement of the particles through inertia when the scoop stopped, with the particles that fell out moving to the right. Inertia rather than wind energy. The CSA Mars Weather Report hasn't been updated since Sol 99 so we don't know what the wind was at ground level. But from the Sol 122 TEGA (1041) image the material ended up on the left of the oven lid as well so delivery would have been on target.

Where was this sample from? Ice or salts?


Mars weather report from Sol 109 is on the Univ. of Arizona Phoenix web page.

Posted by: climber Sep 29 2008, 04:23 PM

QUOTE (ElkGroveDan @ Sep 29 2008, 03:45 PM) *
The Organic Free Blank (OFB)

We do not want talking about the subject of the press conf, don't we ? tongue.gif

Posted by: ElkGroveDan Sep 29 2008, 04:30 PM

QUOTE (climber @ Sep 29 2008, 09:23 AM) *
We do not want talking about the subject of the press conf, don't we ? tongue.gif

They are probably going to unveil a picture of a beautiful sunset. That's all. wink.gif

Posted by: ConyHigh Sep 29 2008, 05:03 PM

QUOTE (ConyHigh @ Sep 29 2008, 07:10 AM) *
Mars weather report from Sol 109 is on the Univ. of Arizona Phoenix web page.

And Sol 112 weather now up.

Posted by: Fran Ontanaya Sep 29 2008, 05:18 PM

Mmh, during the last press conf they wore a witch hat to talk about Wicked Witch.

I wonder if they'll talk about Snow White today. laugh.gif

Posted by: climber Sep 29 2008, 08:26 PM

QUOTE (Shaka @ Sep 29 2008, 07:19 AM) *
mad.gif Aw, hell!.....and I was gonna make a snowman!

so, you KNEW IT : http://www.jpl.nasa.gov/news/phoenix/release.php?ArticleID=1886

Posted by: CosmicRocker Oct 4 2008, 04:02 AM

Hmm, it appears Christmas has fortunately come early to Phoenix. Not only has snow been detected, but also some decent evidence for carbonate and clay. That's pretty exciting news. smile.gif

Posted by: peter59 Oct 18 2008, 06:40 AM

The Phoenix Mars Lander's robotic arm successfully delivered soil into oven six of the lander’s thermal and evolved-gas analyzer, or TEGA, on Monday, Oct. 13, or the 137th Martian day, or sol, of the mission.
http://uanews.org/node/22090

Posted by: akuo Oct 18 2008, 08:40 AM

That's some good news at least. No mention where the soil was from, though. The article also mentions that six of the ovens have been used so far. Therefore there has been one succesful delivery between the last teleconf and this sample acquisition. Likely an OFB sample delivery was finally succesful?

I may be judging the goals of the TEGA without full information, but I feel that the instrument will have failed unless they manage to sample the ice completely. This is seperate from the actual mission goals, which always are set very conservatively for the equipment and the luck of the draw in the actual landing site. The mission goals would have been satisfied if Phoenix had landed in a completely dry place, with no ice at all.

Considering that they have landed in a place with obvious and abundant ice within easy access, it will be a huge disappointment if that ice isn't analysed properly.

Phoenix was extensively tested to make sure that all the critical gremlins in the landing process were found. The same dilligence should be applied on the most important science instruments of the mission. This doesn't help Phoenix at the moment, but must be taken into consideration for complex future instruments with expected mission times many times the Phoenix prime mission.

Posted by: mcaplinger Oct 18 2008, 02:48 PM

QUOTE (akuo @ Oct 18 2008, 01:40 AM) *
Phoenix was extensively tested to make sure that all the critical gremlins in the landing process were found. The same dilligence should be applied on the most important science instruments of the mission.

Well, duh. (For non-native English speakers, that denotes a reaction to a very obvious statement.)

This was done for every instrument on Phoenix. It's just that you really can't test one-shot operations that will be performed in conditions and with materials that simply can't be replicated on Earth, if they are even known in advance. Is TEGA in 20-20 hindsight poorly designed? I have no idea. Was it "extensively tested"? Of course it was.

Posted by: centsworth_II Oct 18 2008, 04:25 PM

QUOTE (akuo @ Oct 18 2008, 03:40 AM) *
...it will be a huge disappointment if that ice isn't analyzed properly.

Yes, but saying "the instrument [TEGA] will have failed unless they manage to sample the ice completely" is way off. TEGA provided much soil analysis data.

Posted by: centsworth_II Oct 18 2008, 04:31 PM

QUOTE (mcaplinger @ Oct 18 2008, 09:48 AM) *
Is TEGA in 20-20 hindsight poorly designed?

Well, duh! The design did not work well at all, in hindsight, when it came to getting sample into the instrument.

Posted by: djellison Oct 18 2008, 05:05 PM

That's the point Mike was making. It was probably the best stab we could have without knowing the exact properties of the soil in advance.

Doug

Posted by: mcaplinger Oct 18 2008, 05:09 PM

Let me know when you guys develop the ability to predict the future, because it would be a great help in mission planning.

Honestly, I think the jury is still out on how well TEGA will end up meeting its mission goals, and whether the design and fabrication were as good as they could have been given reasonable expectations of soil properties. I doubt if the TEGA team will be pulling any punches in the self-criticism department when they write their final result papers.

Posted by: dvandorn Oct 18 2008, 05:35 PM

It would be easier to be equanimous about TEGA if it weren't for the development history of the instrument. I seem to recall that the sample delivery system went through several design iterations.

First, IIRC, there was just an open path for soil to travel to the ovens. Then the concern was raised that larger particles might block the soil chutes, so the screens were added to block all but the particles of appropriate size to successfully reach the ovens. Then it was determined that the desired soil grains wouldn't just fall through the screen, the larger grains would block up the screens, so the vibration motors were added. Then someone noticed that the ice that could be scraped by the rim of the RA scoop wouldn't pass through the screens, so the rasp was added to the scoop to break ice down to particle sizes small enough to pass through the screens (which also served to increase the surface area of the ice enough that it measurably increased the sublimation rate, making it that much more difficult to get it from the ground into the ovens before it all sublimated away).

See where I'm headed with this? The design concept itself started out rather short of being functional, even based on estimates of soil properties that we could easily determine pre-flight, and the instrument design was tweaked several times to try and make it work. Rather than starting with an instrument that was designed from inception to be able to handle everything we could imagine with a good amount of performance margin, we started with an instrument that failed to handle anticipated conditions and was tweaked several times to, with its best possible operation, push performance so that it could achieve its desired function -- with very little margin for error or unanticipated soil conditions.

I'm not finding fault here so much as I'm pointing out that, with extremely tight mass and monetary budgets, it is absolutely essential that you design your systems from the get-go with as much margin for error as possible if you're going to assure successful operation. If the last phases of design and development are spent pushing the system just far enough that its best possible operation just barely covers the requirements for success, you're courting failure. I mean, just look at the number of single-point-failure systems (particularly pyro events) that could have transformed either or both MERs from the incredible successes they have been into short-lived, frustratingly unproductive stationary lander missions. That's a good example of a design that required best operation for success -- and it was the element of the mission that probably caused the greatest intake of antacids amongst the MER team members prior to having all 12 wheels in the dirt.

-the other Doug

Posted by: centsworth_II Oct 18 2008, 07:18 PM

QUOTE (mcaplinger @ Oct 18 2008, 01:09 PM) *
Let me know when you guys develop the ability to predict the future, because it would be a great help in mission planning.

To the question, "Is TEGA in 20-20 hindsight poorly designed?", I just wondered how you could say "I have no idea". Of course, in hindsight it didn't work well where sample delivery is concerned. I'm not saying they should have known in advance.

Posted by: mcaplinger Oct 18 2008, 08:19 PM

QUOTE (centsworth_II @ Oct 18 2008, 11:18 AM) *
To the question, "Is TEGA in 20-20 hindsight poorly designed?", I just wondered how you could say "I have no idea".

Because I don't even know how successful or unsuccessful TEGA has been, much less how much of that is due to poor design and how much to random variation in circumstances.

Of course, maybe you know a lot more about the instrument design and all of the tradeoffs and how it's behaved in flight than I do, which is entirely possible. If not, then I'd say you are jumping to conclusions if you think that TEGA was certainly "poorly designed."

Posted by: stevesliva Oct 18 2008, 09:21 PM

QUOTE (mcaplinger @ Oct 18 2008, 04:19 PM) *
Of course, maybe you know a lot more about the instrument design and all of the tradeoffs


Exactly! Tradeoffs! If we had thrown money at all the soil adhesion worst-case-scenarios, would the instrument that launched have been substantially different, or was the end of the design cycle looming? There is a difference between anticipating every eventuality and designing for them. As dvandorn said, a robust design tolerates more eventualities, but when you're looking at an instrument with eight separate ovens rather than one superoven, it may have been reasonably assumed that there was error tolerance in redundancy.

Posted by: Oersted Oct 18 2008, 11:13 PM

Winston Churchill stuck to a very clear policy during the thirties, in the years leading up to the calamity of WWII. When looking back, he only lambasted the policies that he had criticised BEFORE they were enacted.

Posted by: tanjent Oct 19 2008, 02:50 AM

I am still trying to figure out what kind of ex-ante design would have been sufficiently robust, in line with otherdoug's contention that it should have been able to deal with a wider range of unknown sample properties. MSL will be able to zap rocks with its laser and sniff the vapors, eliminating all those transportation and deposition headaches. This could probably have worked with ice too, but the power needs may exceed what solar alone can supply. Or the deliveries could have initially been made into to a "coffee grinder" to pulverize and homogenize the contents before passing them on to the ovens. Then how to clean up the grinder to avoid cross-contamination of samples? Would one of these solutions, or the many other alternatives that have been proposed stand out enough to have been an obvious choice prior to the mission? I doubt it. But use of the word "failure" just refers to the fact that at the end of the mission we probably won't have answers about the isotopic composition of the water ice and what is dissolved in it. It does not require pinning blame on anyone, and should not be taken that way, (OK - except for the case of the doors not opening properly). Most aspects of the mission have been hugely successful.

Posted by: 1101001 Oct 19 2008, 04:22 AM

QUOTE (akuo @ Oct 18 2008, 01:40 AM) *
That's some good news at least. No mention where the soil was from, though. The article also mentions that six of the ovens have been used so far. Therefore there has been one succesful delivery between the last teleconf and this sample acquisition. Likely an OFB sample delivery was finally succesful?


Oven 6 got the multiple samples named Rosy Red, the latest Rosy Red N and finally Rosy Red N+1. I believe they came from the Snow White neighborhood, Burn Alive Trench.

Emily Lackdawalla has a good trench map and sample list: http://www.planetary.org/blog/article/00001686/

QUOTE
Sol 131: Rosy Red N to TEGA 6


I've followed closely and haven't seen success with OFB sample to oven #2, though I suppose they could be keeping it a secret. My scorecard at the September 29 briefing was:
#4, #5, #0 and #7: used.
#1 has had two delivery attempts of icy soil: one missed and one clumped on screen.
#2 appears to have since been targeted once for the Organic-Free Blank delivery, but that did not succeed.
#6 is barely open. (Now, successfully delivered.)
#3 is unopened.


Posted by: Fran Ontanaya Oct 19 2008, 02:11 PM

QUOTE (tanjent @ Oct 19 2008, 04:50 AM) *
I am still trying to figure out what kind of ex-ante design would have been sufficiently robust


An auger that went through the sample into the oven, maybe. I'm not an engineer.

If the ice table is interacting everyday with the atmosphere, is there much else expected to be found in the ice than in the soil on it?

Posted by: centsworth_II Oct 19 2008, 03:23 PM

QUOTE (Fran Ontanaya @ Oct 19 2008, 10:11 AM) *
...is there much else expected to be found in the ice than in the soil on it?

The big hope was to analyze the water molecules themselves (and the soil contains little or no water), specifically the Deuterium/Hydrogen ratio. By the way, I see in this paper that TEGA was also to measure D/H values in the Martian atmosphere but don't recall hearing anything about this as far as the actual mission is concerned.

http://www.aero.jussieu.fr/info-pratique/seminaire/MarsWC-Site/Program_files/Ellehoj-MWCW.pdf
"The main objective for this work
is to investigate the solid-vapor fractionation
processes of Deuterium/Hydrogen (D/H) in the
ground ice- atmosphere system on Mars....

...Investigating the stable isotope ratios in water
vapor and ice (e.g. in the Greenland ice cores) have
proved to be a valuable method for understanding
the past climate on Earth....

...With its mass spectrometer, the TEGA instrument
will measure D/H values in the atmosphere
and in the Martian subsurface."

Posted by: Fran Ontanaya Oct 19 2008, 10:13 PM

QUOTE (centsworth_II @ Oct 19 2008, 05:23 PM) *
and the soil contains little or no water


It didn't before winter, but now there's frost over it. If they could analyze a good bit of frost, the ratios could be meaningful if that's the same water they are scraping from the ice table. They won't need to use the rasp with the frost, so the scoop won't get warm.

Posted by: Juramike Oct 19 2008, 11:31 PM

I think the D/H ratio from the frost would be the close to the same as for the atmospheric water vapor.

(OK, to be overly anal, there should be a slight theoretical increase in the D/H ratio for frost due to the heavier molecules fractionating out on deposition....)

-Mike

Posted by: marsophile Oct 20 2008, 04:04 PM

QUOTE (Juramike @ Oct 19 2008, 03:31 PM) *
I think the D/H ratio from the frost would be the close to the same as for the atmospheric water vapor.

(OK, to be overly anal, there should be a slight theoretical increase in the D/H ratio for frost due to the heavier molecules fractionating out on deposition....)

-Mike


The whole point of the D/H measurement for both the ice table and the atmosphere is to see if they are different, because that would indicate whether the ice table is ancient (possibly from an earlier ocean) or recent (from H2O frost or snow). It would not be worthwhile to substitute frost for the ice chips because that would defeat the whole purpose of the measurement.

Posted by: marsophile Oct 20 2008, 04:11 PM

Apologies for my last post; it is clear on re-reading that the previous posters were well aware of the rationale for the D/H measurement.

Posted by: 1101001 Oct 20 2008, 05:06 PM

QUOTE (marsophile @ Oct 20 2008, 09:04 AM) *
The whole point of the D/H measurement for both the ice table and the atmosphere is to see if they are different, because that would indicate whether the ice table is ancient (possibly from an earlier ocean) or recent (from H2O frost or snow).


I believe they are coming to that conclusion independently of the D/H measurement. From the September 29 briefing, my contemporaneous notes, not a direct quotation, of Peter Smith's opening was:

QUOTE
Ice is connected to ice in atmosphere.

Shows panorama, and notes patterned ground, polygons and troughs, and where ice is under each. Don't see large rocks or dunes. Not much brought in by wind. Nearby: Helmdal Crater, a new crater (just 1 million years). This is not ancient, but new environment. What do we know?

Snow's coming down. Vapor in atmosphere. Vapor can freeze out on ice layer.


I don't recall how they are coming to that conclusion. In the same, was my note:

QUOTE
Haven't looked at ice isotopics.

Posted by: Ipparchus Oct 25 2008, 05:48 PM

Do you know which TEGA ovens are full and with which samples? I really want to know the last sample deliveries! are we going to have an ice sample delivery? WHEN? Did they succeed with the WCL-3 try to push the sample into the cell?

 

Posted by: 1101001 Oct 26 2008, 07:16 AM

QUOTE (Ipparchus @ Oct 25 2008, 10:48 AM) *
Do you know which TEGA ovens are full and with which samples? I really want to know the last sample deliveries! are we going to have an ice sample delivery? WHEN? Did they succeed with the WCL-3 try to push the sample into the cell?


I don't think they've announced the results of assisting soil into MECA WCL 3. I'm not sure, but I think the clog is shown before and after in robotic arm images from http://phoenix.lpl.arizona.edu/images.php?gID=0&cID=372. It shows a mound that appears to to have been mashed. I haven't compared the scenery, or metadata, to see if it's near MECA WCL 3, nor have I examined the image to see parts of the MECA.

My scorecard for used ovens, at the end of September, is above. I'm pretty sure ovens 4, 5, 0, 7, and lately 6 have been announced to be filled.

Oven 3 still appears unopened.

Oven 2 had an organic-free blank delivery attempt during a windy time and probably little to no matter entered; I saw no announcement of success.

Oven 1 had at least 2 icy soil attempts, one missed, one clumped; I saw no announcement of success.

According to a recent press release (http://www.jpl.nasa.gov/news/phoenix/release.php?ArticleID=1911), they are through attempting sample deliveries to anything.

A Mid-October press release (http://www.jpl.nasa.gov/news/phoenix/release.php?ArticleID=1907) said 6 of 8 ovens have been used, but doesn't specify which, or exactly what 'used' means -- attempted, delivered to, succesfully?

Posted by: centsworth_II Oct 26 2008, 02:26 PM

QUOTE (1101001 @ Oct 26 2008, 03:16 AM) *
...Oven 3 still appears unopened.....

And that is one of the end ovens that should open well. I was hoping it was being saved for one last attempt at getting an ice sample into an oven.

Posted by: Paul Fjeld Oct 28 2008, 07:37 PM

Looking at Mark's page for SOL 152: "Re-place RA..." . So that's it for arm ops? I guess that's what the last few days of grooming and DOC pics were about.

Sad about the ice...

Posted by: Phil Stooke Oct 28 2008, 08:59 PM

"Re-place" might not mean it's over for the arm (though it must be soon) - but it looks like we are getting to the point of alternating charging days and activity days.

Phil

Posted by: Deimos Oct 28 2008, 10:42 PM

A combination of a weekend plan, lower than normal opacities (colder nights), and then high opacities (less power) made it clear that the attempt to stretch out the final days of the RA and TEGA was just not workable. So, as the news release said, the survival heater for the RA, TEGA, and RAC/OM electronics is being shut off tonight (sol 152 afternoon). Any further attempted motion of the RA risks leaving it arbitrarily placed, so I doubt that would happen. RAC/OM imaging may be possible without the heaters, but the warranty is definitely voided. Personally, I expect the RA is already in its final resting place--but if the weather is much improved for sol 152 (in progress), the science plan would execute, attempting to optimize the placement. Either way, there is no option to delay the switch.

The good news is that this frees up much power, so once Phoenix is healthy again, the discharge/recharge cycle can be broken. Even so, the science-days are short. Sol 154 should be the first sol of the rest of the mission, and we should be able to start a final pan of the workspace and RA (and maybe settle any TA-3 door configuration pools).

BTW, I believe the most recent set of RAC images starts here: http://phoenix.lpl.arizona.edu/images.php?gID=42203&cID=375

Posted by: Harder Oct 29 2008, 04:00 PM

Is it known how the last TEGA days have been spent? E.g. heating all remaining samples a bit, just to get to the peroxide released, or doing perhaps only one sample but analyzing it in full?

Posted by: 1101001 Nov 1 2008, 06:53 AM

QUOTE (Harder @ Oct 29 2008, 09:00 AM) *
Is it known how the last TEGA days have been spent?


Nothing in the press releases. But, they've probably been too busy to say, if they've done anything along those lines.

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