MER press briefing, February 2, 2004
February 2, 2004Edit
Press briefing about to start; notes when it's concluded. (The Q&A part is kinda sketchy because my connection was falling down. The first part should be pretty accurate, at least.)
Natalie Godwin: Opportunity has sent us the first 360 color image from the Meridiani Site and engineers have extended her robotic arm so that scientists can study the soil around her.
Jeff Johnson (science team): I am very pleased to announce this morning that the full 360° mission success panorama from Pancam acquired and on the ground. You may remember the Pancam mosaic from day one that Jim Bell presented was referred to as a "postcard" because it represented a kind of snapshot. Now we've completed a full mission success pan. (anecdote about tourists taking pano at grand canyon). This wonderful 360° panorama is in stereo and provides a real sense for "you are there" at the site and gives us a real sense of this bowl shaped depression that we're now in. So without further ado, let's go to the image. This image will start off zooming into the left portion of the image, we'll go right into the edge of the outcrop with all those airbag retraction marks in view, with really dark soil -- this is darker region than we saw at the Gusev site. This is the outcrop as it scrolls that we'll be really interested in spending quite a bit of time trying to document and map as field geologists, the whole outcrop. More bounce marks with the wonderful seams of the airbag itself. As we come upon some slightly larger portions of the outcrop, rocks that are perhaps a few feet in height. The entire outcropping itself is actually very tiny and the layering that we see in the outcrop will be very interesting to us. This area of expanse, looks like there may be some variations. And these wonderful airbag marks here are probably the entry point with the volleyball like textural? and the brighter areas that come in on the dunes there. Just an amazing site that we're still trying to figure out. Hopefully over next few weeks as the rover starts to do it's reconnaissance of the outcrop and sample some of its soils, we'll get a better idea of geologic history of this site. As much as we've been in awe of all of these wonderful Pancam pictures, I'd like to talk about Pancam's ability to do spectroscopy in visible and near infrared wavelengths. You'll remember that Pancam is two cameras. Let's go to that image. On each camera there's a filter wheel. The Pancams are the two dark objects on the outside of the camera bar in this image. See the navigation cams there too. Pancams only about the size of your hand. Filter wheel exposed in that lower image. Each Pancam has 7 positions so we have a total of 14 filters that we can use to image. Pancam is sensitive from blue light out into the near infrared, beyond where your eye can see, to about a thousand nanometers or one micron. Compare that to mini-TES that can go from 6-30 microns. What can we get from all these colored filtered images. Simple case is that the dirt on Mars is very red, very bright in red wavelengths and very dark in the blue. We can do more by looking at how the brightness varies looking through these different filters we can get an idea of the geology. Especially if we want to try to unravel the geologic history of the site. Each mineral has a fingerprint in the near infrared visible spectrum. When we put together a spectrum using these 14 filters, we can compare with samples here on Earth to get an idea of what minerals the area is composed of on Mars. So what does Mars look like. This image shows the calibration target, sundial which is approximately truecolor. I'll focus your attention on the color chips in the green, the red, blue, and the yellow. Plot is two types of data. The solid lines where the colors correspond with actual color chips are spectra acquired of color chips in a lab on earth. These dots are the brightness values from each of the filters that we acquired from actual Pancam data. Those dots are lying right along the laboratory Earth measurements and that's what we like to see. The camera is very well calibrated. So the spectra we extract from Mars will give us a very accurate idea of the true spectral characteristics of that surface. Next slide shows Gusev and a bit of the variability we seeing in these 14 color spectra. In the upper left is the magic carpet region. Focusing in on the rock to the left of the airbag retraction marks. Colors in the lower image correspond to spectra on the right. We've extracted spectra from those spots. You can see that the yellow area is the soil in front of the rock which is very bright in the infrared. A little green area is on top of the rock is even brighter. Rock itself, blue spectrum is very dark. Typical for dark basaltic rocks we see here on Earth. What intrigued us was some spots on the rock. Red spectrum looks a lot like the blue spectrum. Interpretation is that those dots are just little bits of dust that have accumulated in the recesses of the rock face. Next slide from Opportunity in Meridiani. Looking out to the north. The yellow box is of the dark sand dune-like material above the outcrop and cyan, the bluish is out toward the horizon and those two are about the same so to the eyes of Pancam those may be the same types of material. The red spot is a dark portion in the outcrop. Slight variations in darkness that we're starting to investigate. That spectrum is intermediate in brightness. The green spectrum is very bright rock. The bumps and wiggles in the spectra are what we focus on to try to determine minerology of the different rocks. The final spectrum was a small blue cobble that was very flat and dark in its spectrum. We'll be investigating that some more as well. May be piece of ejecta from nearby crater. Pancam will allow us to take those very subtle spectral features and allow us to map those into the scene to try to do some remote geology to get a better understanding of the landing site as well.
Joe Melko (arm engineer): Today on Opportunity was all about the IDD and final checks on in situ payload. First we brought the arm out to ready. Telemetry and pictures let us know all was well with the arm. All the pieces were in the same place :) Confirmation to the team that they had done an extraordinary job. Probably the most complex mechanism on the rover. Only possible because of talent and dedication of the team. Bob Bonnets, Laurie Sarishi, Eric Bomgardner, Ashite, Rich Flieshner, and Rice Billings, (phonetic). Given a tremendously difficult task of fitting it into a very tiny space. Next thing we did was we checked out the RAT, ran motors in free space and it checked out. This first image shows us where it was at when we first deployed it. Entire IDD team showed up today. Great adventure, very happy. The RAT's pointed toward us. Later we moved it around pointed upward. Also checked out the RAT magnets. This is a RAT close-up taken by Pancam. Next we moved it around and exposed Microscopic Imager. We also moved the MI cover. With that, we've covered all the motors on both Opportunity and Spirit and they're all working great. Jeff, our motor and flight software engineer can breathe again. Next we checked APSX and the doors are open just where we left 'em. Instrument looks in good shape. Finally, looked at Mossbauer. Later in the evening we're taking MI of the soil. Tomorrow more MI of soil and putting Mossbauer down on surface.
Jennifer Trosper: In addition to great accomplishments on Opportunity that Joe and the team have made over the weekend, Spirit has made incredible progress over weekend and I am extremely happy to tell you that today we are doing science just like we were 10 sols ago. Spirit is back to the state she was in on just about sol one. Over the weekend we downlinked some additional data and essentially confirmed our suspicions about why the first problem had occurred, related to the number of files in the file system and the amount of RAM necessary to allocate in order to manage those files. We believe that suspicion is correct based on the additional data we got. When we entered into that anomaly we may have had side effects that we don't understand. We've gotten the data down so we will erase and reformat the flash memory tomorrow. Today moving forward with science on Adirondack. First pull back the IDD and change to RAT to brush it. Then we'll do MI and APSX overnight. Tomorrow reformat flash. Then RAT the next day. Spirit is the driving mission. Already strategizing how to drive far and fast.
Q. (lost connection for this question and first part of answer)
Jeff: Still looking at orbital images to see where we are. It may be the outcrop goes all the way around and it's just covered up on the other side. May investigate by trenching. Perhaps we can hit some of that bedrock.
Q. What sized object created depression?
Jeff: Meter or two in size. Could have been a secondary impact.
Q. Is the sense that the evidence you're looking for isn't present in the immediate vicinity so have to strike out to find it.
Jennifer: long term plan from science team is to drive towards the crater and working to do that quickly.
Q. Distant part is looking out of the crater and onto the plains? Contradict earlier assumptions that the materials in and out of the crater were different?
Jeff: They're looking the same to Pancam. Thermal emission data we're gathering is more sensitive and that may account for the differences. Mid-mission we want to get out of the crater and look at that. A little difficult to compare distant objects with near, atmosphere interference.
Q. Now that you have full Pancam how many places you can see out beyond crater.
Jeff: geology team looking at that. There may be some very subtle features you may not be able to see from orbit. For the rest of us, we're just trying to get our bearings.
Q. Sense of where you're going to go in outcrop?
Jeff: As of yesterday science team started thinking seriously about how to attack the outcrop. Need to map it completely with all of our tools and so there's debate about how you do the best science the most quickly and with the best results. One suggestion is to go up to the close part, saddle up to it and take a lot of high-res pictures traveling down the length of it.
Q. Is that the left side, would you follow it in parallel?
Jeff: right, how far off we need to be to use both Pancam and mini-TES and to not hit the solar panel. Every day getting new data that can change our perception.
Q. Outside of the crater, you can get a sense that there may be some blocks on the horizon. Artifacts or real?
Jeff: We're still debating ourselves. Once we get to the outcrop or out of the crater may be able to get a better idea of what's beyond.
Q. Are you really ready to go driving? Does it drive autonomously or with a human driver.
Jennifer: 11 minutes 45 seconds one-way light time. We don't completely joystick it. We have a different approach. Rover is programmed to avoid obstacles. We have a low-level of driving where we only go places in the images we can see, and then collect images at the end of the day to see how it did. May have a mid-day go no-go. As we get into more difficult terrain we may turn on more of our hazard avoidance software. We'll be characterizing things over the next few days. We have a Mars yard here to test things.
Q. How much distance a day, a week?
Jennifer: In the early days, 15 meters or so a day and hope to increase that quite a bit.
Q. What's the operational way you suggest you handle Opportunity given spirit encounter. What have you learned?
Jennifer: The specific problem the number of files is not simply, the resource you need to manage for the number of files is not simply flash, it's associated with the amount of RAM you need to manage those files. So we're down linking additional data about how much RAM is being used. We understand the problem well enough to avoid the problem. Keep your file number low, look at additional data and make sure you don't exceed the limits.
Q. For Opportunity, the first thing is Mossbauer? What's the exact sequence?
Joe: First we'll take a few more MI of soil, then put Mossbauer down and integrate for nearly 24 hours. Then next day we'll spend with APSX for the (full?) day. Based on what we're getting from first two instruments we'll decide what's next.
Q. Dust may settle on solar panels and reduce effectiveness, any other weather that may be risky.
Jennifer: dust is something we do understand but when we did the design we made an assumption based on Pathfinder in coming up with planned lifetime. Other factors are cold which requires more survival heating at night and more heating for science instruments during the day, or at night if we're doing science at night. That can cost us more energy for both survival and science. So, dust and temperatures.
Q. Status of Opportunity's heater and status of determining Opportunity's location.
Joe: The heater is still on. There was a second device put on by our thermal people for this type of case. There's a secondary device that turns it off during the day. At night it's on. With some changes in planning, we can still accomplish everything we intended to do. Much later as it gets colder we'll re-evaluate.
Jeff: Where we are is still being researched. Hopefully by end of the week we'll have a final answer.
Natalie: next briefing on Wednesday at 10am.