On Thursday, October 30, JPL issued a statement saying that Phoenix had gone silent -- that it did not respond to "an orbiter's" communications attempts on the night of October 29 (Denver time) or on Thursday morning, both of which would have been (I think) in the afternoon of Phoenix sol 153.
Apparently, though, not ten minutes after that statement had been issued, Phoenix was heard from again -- this was shortly after 14:00 Pasadena time, or first thing in the morning of sol 154.
So, currently, Phoenix is in "a precautionary mode triggered by low energy," according to an update to the October 30 statement. "Mission controllers judge the most likely situation to be that declining power has triggered a pre-set precautionary behavior of waking up for only about two hours per day to listen for an orbiter's hailing signal. If that is the case, the wake-sleep cycling would have begun at an unknown time when batteries became depleted." This is a form of safe mode, and, if I understand the buzz correctly, we are actually seeing the operation of the "Lazarus mode" that could theoretically (but probably won't) result in Phoenix waking up after the Martian autumn, winter, and spring passes in the polar north.
The mood on the mission appears to be on a roller coaster. Phoenix is very sick, and at times, people seem to think that the mission is done. There's certainly fairly somber (or at least resigned)-sounding posts coming out of the Phoenix Twitter feed, such as "In case we don't get this chance again, thank you all so much for the questions, comments & good wishes over the mission. It's been awesome." There's even a contest going at WIRED Science to compose a Twitter epitaph for Phoenix. However, there's also, occasionally, real hope that they can get back to doing some final science -- among the most important unfinished business being to try to grab a final set of snapshots of the "work volume" as it stood when the arm stopped operating.
Those of you who are (like me) image buffs are probably curious about how much progress Phoenix made on the "Happily Ever After Panorama," which it was to work on more and more as power levels limited Phoenix' ability to use its robotic arm and power-hungry instruments like TEGA. Mark Lemmon kindly provided me a "tracking image" showing Phoenix' progress on this data product.
NASA / JPL / UA / Texas A & M
Status of the 'Happily Ever After Panorama' as of Phoenix sol 141
This is a snapshot of the status of Phoenix' "Happily Ever After Panorama," the panoramic view of its landing site that it was working to complete before it succumbed to the Martian polar autumn. As of sol 141, Phoenix had acquired 37 frames out of 100 defined for the panorama. Most had a few missing packets (black spaces) due to transmission errors, which would not have been filled in because there was not space in Phoenix' flash memory to store the images for later retransmission. The area to the north of the lander was omitted from the planning while the robotic arm was still in motion; the plan was to fill that area once its use had been suspended.
There are a lot of gaps, and, like I said above, one of the most critical gaps is the area in which the robotic arm had been scraping and trenching and poking and moving rocks. So I really hope they manage to wake Phoenix up long enough to get that, before the setting Sun finally kills it.
And I know many of you are still curious about the microphone. I'm sure that if they had turned it on successfully and heard anything, we would have heard about it by now. But I've also heard that, if they can wake up Phoenix and get it back doing science, they haven't yet ruled out trying to turn on MARDI. Keep your fingers crossed that we haven't heard the last from Phoenix!