Emily Lakdawalla • Jul 09, 2008
Phoenix sol 43 update: Lots of imaging, hacking at Snow White, first touch for TECP, and more
I called Mark Lemmon, head of the Phoenix imaging team, this morning for an update on what's been going on with Phoenix since we last checked in, on sol 36. It's been an eventful week. Here's the highlights:
- The Mission Success Panorama is, as of this morning, complete -- that is, all the data bits are on Earth. Work still remains to assemble it, and Mark has some ideas for things he'd like to shoot again to improve it, but we can now assemble a full, 360-degree panorama of all of Mars that Phoenix can see in full color.
- A tiny sample was delivered to the Optical Microscope on sol 38 ("tiny" was what they requested). They had to wait a couple of sols for the wet chemistry lab to be ready (done with its first analysis), and then delivered everything else that was in the scoop to the wet chemistry lab on sol 41. Mark says that delivery was "perfect."
- The Thermal and Electrical Conductivity Probe (TECP) on the robotic arm finally touched soil on sol 43. The team is "excited to finally have that in play."
- Mark said they've "really been hacking away at Snow White" and finding that the ice below the surface is "every bit as hard as we expected it to be." They have not yet managed to get any icy material into the scoop. Since acquiring an ice sample for delivery to TEGA is now the highest priority, they are getting ready to use the rasp on the back of the shovel to get some ice. Mark says they will almost certainly have some false starts with their first attempts to get ice samples using the rasp for the first time.
- This whole TEGA thing is slowing them down a bit, but they're making do with the cards they're dealt. Fortunately the power situation has been excellent; they're even talking about doing a 24-hour sol, with observations of the atmosphere around the clock.
- They are just about ready to start using the Atomic Force Microscope on some of the Optical Microscope samples.
- Also, some rather impatient people have been emailing me to ask why there's not been much in the way of science results yet. Hold your horses! The mission's not even half over, and the science team is 100% occupied just operating their spacecraft. I asked about conferences, and Mark told me that the first conference at which there will be a big presence from Phoenix people talking about initial results will be the American Geophysical Union meeting in December (which is, conveniently, while Mars is in solar conjunction, severely limiting activity).
I asked Mark what their goals were for the two-day Independence Day holiday. He told me he hadn't really wanted to take a break himself but that there were some mission-critical personnel who'd only taken off one or two days since Phoenix landed who really needed to be forced to take a holiday, and that he thought that in the end it was probably a good thing. In any case, no activities with arm, TEGA, microscope, or wet chemistry lab were permitted, so they were able to do lots of imaging. They did a full deck panorama, and several multispectral spots. In the post-mission success panorama era, he said, they're trying to focus on targets beyond the arm's work space -- targets that are out of reach like interesting rocks and polygons, looking at them at high resolution or through many color filters or both. They're going to be squeezing in those kinds of imaging opportunities for some time.
After getting those multispectral spots, he said they need to take stock of what kind of data volume they think they are going to get through the rest of the mission, and use that number to determine what kind of panorama they can reasonably acquire in that time. They can make lots of choices about how good a panorama to take: how much compression, stereo or not, multispectral or not. He said that because panoramic imaging is "tactically easy" -- i.e. not time-consuming to plan, now that it's becoming routine -- there will probably be much more of it after the prime mission is over, when the team disperses to home institutions, and especially after they have to quit using the robotic arm (because of power limitations), which now looks to happen some time in October (the power situation is very good). He said his first priority is probably going to be a high-quality (not much compression) stereo panorama.
Before then, there are some things Mark would like to do to improve the now-complete Mission Success Panorama -- things like getting a shot of the part of Mars that was blocked by the robotic arm scoop as it was poised over MECA; and he'd really like to get a nice vanity shot of the robotic arm posed within its workspace as though it were getting some work done. It's not mission critical but would be an archival photo.
About science versus data acquisition, Mark said they are putting their full-time effort into operating the spacecraft, doing only as much analysis as necessary to make sure they are "doing the right thing next." Data analysis will come later, beyond the Phoenix mission, probably. They don't even have a plan together yet for the first science papers to be published. He said he didn't start thinking about his first Spirit science papers until six months into the mission, and the first publications came out in the fall, nine or ten months after the January landing.
For conferences, they're really looking ahead to the AGU meeting -- no matter how well the lander is doing, it'll be Mars solar conjunction so they won't be able to do anything operationally. He said a few people will likely be at the Division of Planetary Sciences meeting in October but wasn't sure about what would be presented.
About the sol 38 Optical Microscope delivery, he said they had about 15 cubic centimeters of hard-won sample in the scoop, and they really wanted it for the wet chem lab, so they told the arm team to deliver "between 0 and 15 percent" of it to the microscope, preferring to risk getting nothing into the microscope than having nothing for the wet chemistry lab. They did deliver a tiny amount, and then had an "excellent delivery" to the wet chemistry lab (which he pronounced "wikkle". He said that results of the second wet chemistry lab analysis, whatever they may be, are being kept mum so far. He also said they are referring to the sample chambers as numbers 0 through 3, with 0 being closest to the camera and 3 being the farthest. So the sol 41 delivery was to WCL 1.
About TECP, he said that as of sol 43 "We had four needles in soil -- we are quite excited to finally have that in play." It went into one of the "preserves", areas of the work volume to be left untouched for future use by TECP, a target called "Vestry," if I heard him right. He said that they tried the first time on sol 41 but were conservative and didn't quite get the needles to the surface. He said that on sol 43 they had good contact and that the TECP experiment is underway.
He said they're now working out strategic plan for the Atomic Force Microscope, but its characterization is not quite complete. Unlike TEGA and the wet chemistry lab, Atomic Force Microscope needles can be re-used "an indefinite number of times." He said they now have a backlog of samples in the optical microscope ready to be examined by AFM, once they finish the characterization, which should hopefully happen today.
There's an obscure entry on his image tracking page about "RAC divot monitoring." He explained that they have been "really hacking away at Snow White, and demonstrating that it's every bit as hard as we expected it to be." They've been trying to scrape away at the surface of the ice, producing some ice shavings on the tip of the blade, then imaging them up close with the robotic arm camera to watch and see if they sublimate. But this is hard because in order to catch the sublimation, they have to scrape, scoop, and image in one day, without having any images come down to Earth to see if they managed to scoop any of what they scraped (and without knowing if the scraping produced any scoopable shavings). This hasn't been successful, so they are now facing using the rasp. He said they had hoped to use the rasp later in the mission, but the problems with TEGA have elevated the priority of getting an ice sample. And he said that the first few attempts to get some samples with the rasp are likely to include some "false starts." All in all it's still some days yet before they're likely to have an ice sample that they can deliver to TEGA.
In the meantime they're building up a long list of stuff they have to wait to do. For instance, there is a pile in Snow White that is sister to the one that went into the optical microscope and wet chemistry lab that they really want to put into TEGA, but they obviously have to wait for the ice sample to go in first. So "things will speed up once we figure out ice sampling." It may be a bit frustrating, but remember that ice is the whole reason Phoenix went to Mars -- getting that into TEGA has got to be Phoenix' number one priority.
That's all I have time for today -- sorry I don't have time to plug in any images. I've updated my sol-by-sol summary, and my robotic arm camera raw images page is updated as of yesterday. Don't forget I'll be on my Ustream channel for a chat at 20:00 UTC today -- hope to see you there!
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