Phoenix - spring images, HiRISE views of Phoenix after the long, long winter Options

[mcaplinger]

For the January attempts, Odyssey was only listening and not hailing.

Is there a source for this information? As best I can tell from this document -- http://trs-new.jpl.nasa.gov/dspace/bitstre...4/1/06-1429.pdf -- PHX will never send without receiving, so ODY listening without hailing is useless.

[vmcgregor]

It's the way the Lazarus mode works. The source is the Phoenix mission team at JPL (originally from Chris Lewicki and Barry Goldstein). The chief telecommunications engineer for the Mars Exploration Program, Chad Edwards, who led the January listening campaign, confirms: "Phoenix's fault mode would have it transmit to any overhead orbiters - without needing to be hailed - during portions of each 2 hr wake-up session (in between 19 hr hibernation periods). We do not need to hail Phoenix to trigger that behavior."

[marsophile]

Assuming Phoenix in Lazarus mode initially goes through a "Goundhog Day" state where it wakes up with a clean slate, tries immediately communicating, runs out the battery, and repeats the next day (instead of trying at various times), would the recent attempts to pick up a signal have coincided with the likely transmit times? What is the local time at the PHX site during the ODY passes?

[Deimos]

I don't know the details of the passes, but expect they had a reasonably good sampling of local time. It's around a 5AM/PM orbit, but the polar latitude makes many more times accessible. During the mission, it was occasionally possible to use 3 or 4 consecutive ODY passes (every two hours through the afternoon and evening in that case), and that was for a higher bit-rate than would be in play now.

Hmm. 30 passes in ~3 sols would be all or most opportunities--you could get roughly every hour of the sol, with some resampling, with numbers like that.

[mcaplinger]

30 passes in ~3 sols would be all or most opportunities--you could get roughly every hour of the sol, with some resampling, with numbers like that.

Right, but each pass only lasts a max of 7-10 minutes, and I don't know what duty cycle of transmission they were using (since I can't find any documentation that such a mode even existed.) Maybe they send tone for a few seconds every few minutes? Mark, do you know anything about this mode?

[Deimos]

Having refreshed my memory, I have a bit more info. The first confirmed lazarus communication was sol 154 in a 5:18 AM pass, lasting about 2 minutes. Phoenix was described as being in a mode of continuous communications attempts over 2 hours or until power runs out. The next sol, a signal was seen at 8:20, but was faint (ODY was low in the sky and the path was long). The next sol, the 13:19 pass worked ( 12 minutes!) giving a record of many, many unsuccessful attempts to wake up and a power state that would not survive the night (again). An early AM pass had apparently showed some sort of signal, too. The last signal was detected (without data) at 157/8:24. After that, it was never clear whether the lander was trying to awaken, and failing; awake at unfortunate times; or had entered a particular (permanently) unrecoverable state. So, I think the intent is constant comm for most of 2 hours, which uses many W-hrs, but it may use <10 minute cycles of shorter attempts.

[Deimos]

Rumor has it the second ODY search is underway, with ~60 contact attempts this week.

[marsophile]

http://www.jpl.nasa.gov/news/news.cfm?release=2010-063

10 down, 50 to go for this month's campaign.

[Hungry4info]

Not much ice in the area now.
http://www.nasa.gov/mission_pages/phoenix/...ix20100226.html

Not going to claim certainty on this, but it really looks to me like the solar panels broke off.

Attached thumbnail(s)

 

[djellison]

I can read it either way. The fact that there are two white patches just south of where the arrays are would to me at least, infer shadowing by the arrays hiding those areas from sublimation. I THINK I can see something where the arrays should be. I just don't know.

[Hungry4info]

I THINK I can see something where the arrays should be. I just don't know.

Oh for sure.

It's the right-most object's extended distance from the lander and the lack of conclusive shadows from the left and right bright spots that concern me.

[SteveM]

I did a 50% Equalize to the lightness component of these images. The Lander now appears very dark and where it would cast shadows there are two white patches (especially noticeable in the rightmost (later) image). I've been looking at a lot of snow this winter and this image looks like frozen precipitation not melting as rapidly in the shadows of the solar panels.

Steve M

[Hungry4info]

But remember the sun is moving around the sky such that the solar array's shadows will not stay in one spot. I would not expect their shading to provide ample protection to any patch of ground.

Edit:

Especially if the lander body itself doesn't do this!

[MahFL]

As the sun gets higher with the seasons' progression, will we get better pictures ?

[briv1016]

Third and final communication attempt to begin on April 5th.

Now I'm not sure about the credibility of this source, but according to this article they might be considering a fourth communication attempt in May around the solstice. (Assuming the one next week fails.)