Probably not, but salts don't need to turn to liquid to be somewhat sticky. Incidentally, hydroscopic simply means that they absorb moisture (true of most salts) and doesn't refer to freezing point depression; deliquescent means that they absorb enough moisture to turn to liquid - only possible at temperatures above their eutectic temperature with water. I think that's what you meant.

-- HDP Don

Here's an animation of the digs, using images from sols 12 and 14.

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Can anyone venture a guess as to why anyone, anywhere would even *bother* to transmit an image product like this all the way from Mars to Earth?



I mean, quite frankly, there was just as much useful information in that Mars 3 surface image...

-the other Doug

But you don't know that till you download it ( and Phoenix doesn't have the capacity luxury of saving all the images over several days for thumbnail downloading and selective downlinking thereafter )

It's classified as Sky survey tests, it's taken with a solar filter, thus it would be a very very very long exposure, thus it has a lot of noise in it. Given that there's no night-time to get noise readout images, it's probably the best they can do. Flatfield, bias, noise, are all important contributors to making sure you get the very best calibrated imagery that you can. So yeah - you may be thinking 'what the hell sort of a picture is that' - but it will make sure all the other pictures are as clean and calibrated as they can be

Doug

Well, yeah -- but this is a downsampled image, and so heavily jpegged that there is literally no usable information, at least in this raw form.

I guess I would have thought that the SSI team would have been able to predict that the combination of a very poor-resolution image and the heavy jpegging from the downsampling process would render such an image scientifically marginal. Then again, I really have no idea whether the very heavy artifacting is also present in the actual raw data, or if it's as much a result of the stretching for presentation on the web as it is due to anything that happened aboard Phoenix.

I was just struck by the apparent utter uselessness of the image, I guess...

-the other Doug

Looks like a calibration image ( 11F6-5: Survey sky test ). It's using the dark solar filters to look at the horizon using an crazy long exposure time to (I'm guessing) characterize the background noise.

For you.

For Mark it's probably quite usefull in establishing the noise level of long exposures when the camera is getting hot at mid-day after lots of imaging.

Pancam has done plenty of similar things.

Doug

The MET site called those images "Tactical water sky test". What they heck is a "Tactical water sky test"?

The Peter Pan - sol 14
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Hope it doesn't rain or snow.......ha ha ha.............

Its not as flat as a pancake is it ? Quite interesting in fact, can't wait for the full res colour...........

The Peter Pan - sol 15
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Thanks!

One of today's image pairs is just crying out for the 3D treatment...

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Where we can confirm that the 3 rocks (1 meter) per hectar seen from MRO pictures is correct. Impressive
I tell you, the Peter Pan full colour will be something as dramatic as Victoria's or Everest's pan.

Edited : Very nice Stu

... and another...

Click to view attachment

I can't see any sign of the parachute in this new image. According to the hirise imagery it should be immediately to the right of the backshell. Another sign that this landscape isn't flat as a pancake!

Backshell in approx. natural color:

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This is still half the maximum SSI resolution. Is the backshell really coppery-red from the inside? There's a dark object way out in the distance beyond the smaller rock in the foreground. A large boulder?

Fred, the HiRISE team says the parachute is lying in a small depression so that's why it's not visible to Phoenix.

"Apparent" being the operative word. ;^) The useful information content per bit downlinked is probably competitive with the median Phoenix image. Not in the JPEG, of course--that's clearly not useful. The sequence is actually a test of a plan-B observation, since the plan-A one is temporarily off the table (no, it's not pretty either, but not as bad). After sol 16 and before sol ?? it'll change some--but it still won't be pretty.

Kewl -- thanks, Mark!

I surely wasn't trying to be nasty or anything. I just took a look at the image product and nothing in my mind could figure out of what use it might be. I'm glad to hear it's not nearly so badly artifacted in the raw data.

-the other Doug

Plan-B? Plan-A? What won't be pretty - these sky shots or something else?

Most likely yes. Probably blasted from the nearby crater (wats its name?).
The terrain is actually very interesting (the polygons are awesome) especially the rocks (to bad they dont have rock analyzing instruments )
The original surface rocks that we see as light_coloured seem to have suffered significant weathering (glacial?).
The more angular darker basalts are probably from recent impacts.

Anyone want to comment?

Yes, that dark object appears to be a big rock in the distance when seen in higher resolution.

It probably should be visible in the pre-Phoenix HiRISE image based on the lander location. Here's the color shot merged with a full-res red frame in an attempt to get best of both worlds. Not terribly accurate.

I can't wait until the full set from this mission is on the ground and I can start building some super-res shots of the stuff on the horizon. BTW, this still feels like an MER mission. As long as it is digging the hole and we don't have full resolution color coverage for the whole 360 degrees, it seems like new goodies just keep showing up. By the way, perhaps I have missed something obvious, but why can't Phoenix downsample images and then transmit selected full resolution shots later a la MER? Is it a memory issue? I imagine it has to do with the fact that while SSI has a pancam CCD and it is the "new" mission to Mars, this is in many ways a mid-nineties spacecraft.

http://www.lockheedmartin.com/data/assets/14803.gif - all goldish MLI on the inside

V1, V2, MPF and MERA backshells all landed right-side up. MERB's didn't, and the 'chute is very tangled, I put that down to the chute not re-inflating after the end of the RAD firing. This one looks intact, but with the 20 kph winds, could well have come in at an angle and pitched over on impact.

Doug

Yeah - Phoenix is pretty sucky for flash storage. They can't take half a full 360 in four filters at full res in a single sol and downlink over a week like MER can - there isn't room.

Doug

I only found out today that the lossy compression used on SSI is not the wavelet-based ICER algoritam used on the rovers, but ordinary JPEG. A step backward, no doubt it's Pathfinder heritage. I'm fascinated by the engineering aspects of these things. The imagers on the MERs were very well documented (and accessible to ordinary folks). I wonder if more details about the detector bit depths, downsampling method to 8 bits (LUTs?) etc could be found.


Ah, so it's not a processing artifact after all!

Here is my own color interpretation + merging low-res color data w/hi-res red pics. Enjoy !
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And here's my version. I have completed two sections of the "Peter Pan", but during stitching of the other section, I found there was a little bit of color correction to do .

Looking the other way from that sol 15 Peter Pan sequence. The runouts + Peter Pan from sols 13+14



Click image

About 150 degrees across, mixture of R(ABC) and R(1BC), still a work in progress.

James

Oh my gosh. The RAM and flash memory combine to a whopping 74 megabytes. By comparison, the MER rovers have 256 megabytes of flash memory. Still small by today's standards, but a whole lot better. Of course, had it had its original CCDs, that would have been just fine. This is bringing back memories of my computer equipment in the late '90s.

On the other hand, being in the extreme north PHX has more exposure to the relay satellites MRO and ODY than does MER. The MERs get about 5 passes per sol with at least 10 degree elevation (MRO+ODY) while PHX gets about 16.

74MB...

I was wondering why there are so many downsampled images. Phoenix is quite an old spacecraft.

Yes, and 74 megabytes includes memory for other data and RAM used for operating the spacecraft. Granted, it isn't just age...like I said earlier, had SSI flown as a virtual clone of Pathfinders' IMP, memory wouldn't be nearly as much of an issue.

They sure had enough time before launch to upgrade the flash, and I assume this could have been done at minimal cost.

Not necessarily. Systems engineering, integration & testing (usually abbreviated as SEIT) is a time-consuming and tortuous process for spacecraft, and changing baseline configurations is not lightly done. You don't get a second chance, so you'd better minimize risk whenever possible. In this case, the Phoenix designers apparently traded off onboard memory capability for the known reliability of the tested design.

They could have loaded it up with 10 gigs of memory, but if some unexpected interface or configuration problem were to crop up that could not be fixed via creative software patching even before launch, then it's game over--launch opportunity missed would be the best outcome, but also quite possibly the kiss of death for the entire project due to schedule and cost constraints.

These guys walk a very fine line; it's more of an art than a science to achieve mission success with a planetary exploration spacecraft.

nprev is right. Switching out memory would require all sorts of new testing. Weird problems can crop up, and the results can be really bad...remember Spirit's scare a few days into the mission?

This post http://www.unmannedspaceflight.com/index.p...st&p=117197 from Mark goes into it a little bit.

Interesting to look at the Phoenix Data Archive Plan:



At a nominal 50Mb/sol (~6MB/sol), or even three times that under the "best circumstances," if it had a 1GB memory, what would it do with it?

The MERs were planned for about 4 times more downlinked data each for the primary mission (also 90 sols):

Now that we get MPL and Exomars in a few years this get's me thinking in what timeframe we have use for a dedicated telecom orbiter or a science orbiter with higher bandwidth. Especially since the three we have are somewhat aged by that time.

Check out Relay Communications Strategies for Mars Exploration Through 2020.

The bottom line in that paper is that with the cancellation of the Mars Telecommunications Orbiter, "second decade" Mars communications will rely on combination science/relay oribters like MRO, using the same radio as the latter, the Electra software-defined UHF radio. That radio supports up to 1 Mbps from landers. MRO can transmit back to Earth at 600Kbps-5Mbps depending on Earth-Mars distance, DSN facility used, etc.

The advantage would be in being able to take a full panorama in a short number of sols to minimize the effects of changing sun angles and any surface changes between frames. Not huge, and not worth risking the mission with unproven memory, but still an issue. With regard to MER panoramas, the obvious advantage would be to take the whole pan at once and roll away, transmitting it as time permits.

LOTS of sol 16 images now available...

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Any clue what this is? They keep imaging it:

That's the Organic-Free Blank.

Cool - so that is where it is! Well, apparently it is still there

Will be interesting when they start milling that blank to feed TEGA. I wonder if that involves a dedicated use of one of the ovens or is combined with another sample's processing?

Airbag

The Peter Pan - sol 16
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It looks to me like it would involve dedicated use of an oven. But the blank will not be analyzed unless organics are detected in one of the Mars samples. Then the blank will be analyzed followed by a repeat analysis of the Mars sample. So, detection of organics in one Mars sample (samples from one stratum of a dig) will use three TEGA ovens!

I don't quite understand how the blank works. How is it representative of all sources of contamination that might come from Phoenix? Also, since it's been uncovered, isn't it being contaminated by Mars?

New color image of the trenches:

That is one of the images for today's briefing, which starts at 1pm central (top of the hour) and can be listened to here.

Anyone tuning into the briefing?