 |
 |
||
 |
|
||
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
||||||||
 |
Projects: Red Rover Goes to MarsStudent Astronaut Cheng-Tao Chung
Spirit Sol 41 / Opportunity Sol 20Saturday, February 14, 2004 On my first day here, I, Kristyn, David, Saatvik attended the Science Context Meeting where scientists summarize what the Mars Exploration Rover had done and what it will be doing. There were a bunch of priorities listed and they had to choose what they wanted to take out of the sequence. We’d be moving on soon after the rock Mimi. But we’d be gathering less detailed data if we moved further away. We went back to our cubicles to learn about how to calibrate the Mars Dial images. The directions were at first quite confusing, but after I few images I started to gain speed. I created color images and 3D images of the Mars Dial. Dials are important because they show true solar time. The time on our watches is just approximate. The Science Downlink Assessment Meeting after the Mars dial lessons was very interesting. John Grant conducted it. Debates were fired whenever someone points out an interesting target. At first the fact was clarified that Mimi is a small rock and certain instruments might not work on it, so the main discussion went to where to put and what to use with robotic arm. A lot of scientists thought that Mimi is very unusual and as much data should be gathered as possible. Then someone wanted to do gather more information form the surrounding sand dunes for a complete investigation. The debate soon turned back to where to put the robotic arm on Mimi, the dustier part or the cleaner part? And because the sides are quite ridged, someone made it a point that it’s the most interesting part. Given my choice, I would check out the spot where those three areas meet. But, it might damage the instruments. We’d find out soon at the Science Operation Working Group Meeting. Spirit Sol 42 / Opportunity Sol 22Sunday, February 15, 2004 Kristyn and I met KJ Walsh, our mentor today. He let us tour the different floors. Scientists talked about trenching soils at the Science Context meeting. The rovers dig trenches by stopping five wheels and make one wheel move back and forth until the soil underneath the surface is exposed. Analyses of the soil are done both before and after the trench to compare the differences between surface and subsurface information. They also discussed what instrument was best used to test the hardness of rocks. We learned about the Rock Abrasion Tool (RAT) after the meeting. The RAT Payload Element Lead (PEL) Steve Gorevan explained how it worked and we actually held the RAT. I just had a part of the rover in my hands! The RAT was actually much more complicated than I thought. First, the robotic arm would reach out for the rock until the outer rims of the instrument detects the impact. Then the arm stops pushing and lowers the spinning blades. It detects the highest point of the surface. Blades lower altitude to a point and slice everything away at the height. Then they move lower and slice everything away at that height. At the same time the blades dig into the rock, two brushes clean away the dust. This goes on for 3 or 4 hours until a 3 to 5 mm hole with a diameter of 45.5mm is dug in the rock. After calibrating some images when we got to our cubicle, we went to the Science Downlink Assessment Meeting. They talked about which way to turn on the slope and which wheels to use to dig. The trenches are either shallower with more exposure or deeper with less exposure because we are on a slope and the rover might slide. Then we met a senior at Cornell University. His work is to calibrate images and sort bugs from software. He gave us some information about what problems images have and why it is important to fix them. And again, we got to see all the work engineers have to do before scientists could do their research! Spirit Sol 43 / Opportunity Sol 23Monday, February 16, 2004 After calibrating the Mars Dials, Kristyn and I went to the Science Context Meeting. We saw a picture of Meridiani Planum, the landing site, from the view of Mars Global Surveyor and actually saw the rover and the parachute. During the meeting, scientists said that switching instruments on the robotic arm take a lot of power. Since we’re trying to get a full charge on sol 24, they are going to do a measurement during the day, switch the instrument before the sun goes down, and do another measurement at night. After the meeting, we talked to a under-graduate. She told us that since we landed in a crater, we better look at the outcrop. The meteorite already pushed the soil out for us so we could look at the different layers of rock. We looked at the impressions of the wheel tracks in the soil and scientists talked about how the tracks stand out so clear. The focus of the Science Downlink Assessment Meeting is the newly dug trench on sol 22. Scientists wanted to do parallel observations of inside the trench as they did at the surface before the trench was dug on sol 21. The problem is, should we place the robotic arm at the floor of the trench or on the walls of the trench. So there will be discussions about where to put the Microscopic Imager, the Mössbauer and the APXS. Scientists want to make maximum use of the trench. There would be more observations of the trench after the rover drives for a distance towards the outcrop next sol. Spirit Sol 44 / Opportunity Sol 24Tuesday, February 17, 2004 Kristyn, and I met our mentor Joe Oliver today. His job is to escort us around Jet Propulsion Laboratory. The rover did the research with the robotic arm and is planning for more robotic arm analysis next sol. "Now we've dug the trench, we better make sure we do the science right before we leave." Said one of the scientists. After the meeting, some scientists talked about using the Mössbauer for a close analysis on the wall of the trench. Others wanted to use APXS first. There was a lot of discussion. Energy sis the main issue for this sol's planning for what analysis will be done in which order. It looks like using the Instrument Deployment Device (IDD) is a complicated matter. We went out to the rover test bed, where scientists simulate the condition on Mars. Then, a scientist told us that there are things that they can't simulate. Sunlight, for example, is replaced by many lights in the lab. However, this means there is no strong shadow. The rover was "afraid of its own shadow" on Mars (it thought it was an obstacle), because that factor was ignored in the test bed. The rover and lander were both there, full-size and the rover was moving. The lander was much smaller than I thought it would be. It seems like the rover wouldn't fit. The whole environment is very dusty. Dust accumulation on the solar panels is what will eventually shut down the rovers because the solar panels will be covered and unable to absorb the sun's energy to charge the batteries. Spirit Sol 45 / Opportunity Sol 25Wednesday, February 18, 2004 Kristyn and I went to The Planetary Society for the filming of the TV program “TVO Kids.” First they took shots of Kristyn in front of the Planetary Society building. Then they went inside and introduced the rovers that could be driven on web. They simulated the real mission terrains such as the Pathfinder landing site. We could explore alien terrains through the rover’s camera. I drove the rover around in the background while the host interviewed Kristyn. Finally, they threw us questions and we got to answer them on TV! After a long morning of shooting from the Canadian TV crew. We went down to the Science Context meeting. They talked about how much power the rover had available, which affected their planning. The Canadian TV crew followed us for a few shots at JPL and continued with “the Martian mailbag” (the answering viewer questions). The show seems pretty entertaining. Because we’re on a hurry for the Science Downlink Assessment meeting (SDAM), they’ll take some more shots after we return. At the SDAM, scientists discussed the plan to move towards “El Capitan.” Scientists are already planning ahead for what to do at the outcrop. They are going to investigate the spherical objects (blue berries) and the layering of rocks. Spirit Sol 46 / Opportunity Sol 26Thursday, February 19, 2004 At the presentation about The Spitzer Space Telescope, the chief scientist Michael Werner showed the scientists how great infrared sensing was for cosmic observation. The Spitzer Space Telescope currently in a solar orbit and is expected to operate for 4 to 6 years. All three of the instruments it carries have the ability to measure different infrared wavelengths. With instruments in infrared, well be able to see the heat radiation of stars and see through dust. Seeing through dust is a great thing because we could see the center of galaxies that weve only been able to see the outside of. This also tells us about he formation of stars by observing dust. There are stars that are dark in visible light and light in infrared and well see dust heated by stars. There are even stars that are only visible in infrared and invisible in visible light, scientists are still figuring out what those were. Observation of spiral arms of galaxies is made easy by infrared. Two major natural phenomenons that occur in space and involve heat activity are starbursts and black holes. The telescope would surely be beneficial to those observations. They are pretty sure that theyre observations are accurate since they did spectrums of the same spot twice and the results were the same. So this makes them believe the difference on other spots that they observe. Scientists had to send infrared observation instruments into space, because on Earth, heat radiation is all around that greatly affects the result. So the telescope is shielded by the solar panel and outer shell from the sun. And inside, it is cooled by cryogen. The Spitzer Space Telescope has evolved from a heavier and money consuming version to a lighter and less expensive version. The three instruments on board which are the IRS, MIPS, IRAC, are able to measure different wavelengths in the infrared. Finally, Michael Werner asked every scientist who is involved in The Spitzer Space Telescope to stand up and we gave our applause. KJ, Kristyn and I hurried to the science context meeting, where yestersols activities were summarized, and plans for the next sol discussed. Then we took a look at a high detailed picture of the outcrop. The layers in the separate rocks seem to curve. That, explains a scientist could be caused by two factors. The first one could be that it has something to have to do with geologic movements. But we need to find an individual rock with the angle to prove that, or its probably just rocks that piled up after the impact of the meteorite. Then we went to the JPL store and bought some souvenirs for my classmates. We also saw the out door Mars Yard with a rover operating its camera. We had fun today. Spirit Sol 47 / Opportunity Sol 27Friday, February 20, 2004 Today, Kristyn and I met our next group of student astronauts, Nomathemba and Camillia. Before the science context meeting, we met Morten Madsen and Watter Goetz, the two magnet scientists, and also Bruce Betts from The Planetary Society. Bruce was holding a replica of the DVD that was sent to Mars with the magnets that collect magnetic dust. Three LEGO bricks with the color blue yellow and red hold down the DVD on its side. And a magnetic LEGO figure stands in the front of the DVD. As Bruce explained to us on what the things on the DVD meant, Matt Golombek lead a group of under graduates into the room and explained how the schedule works. “A Martian day is about 24 hours and 40 minutes so the schedule would be 40 minutes late every day. So in about 2 weeks my whole schedule would be 12 hours late. A lot of people here are in constant lag. Drinking coffee helps.” Then the Science Context meeting began. On sol 27 the rover did remote sensing and did Microscopic image and Mossbauer and microscopic image on a piece of sand and a rock. Remote sensing includes Panoramic Camera and Mini-TES. Tomorrow might be an IDD day—that is, a day when they use the instruments on the arm. This is called “in situ” instead of “remote sensing.” Matt suggested that on IDD days, we could have Siesta (naps) since it really helps save the rover’s power. Some scientists in the Geochemistry group said that they should start analyzing the temperature of a piece of soil everyday at the same time. Let it become a daily routine. This would give us valuable data of the daily Martian temperature. After the meeting, we talked to the scientist Jascha Sohl-Dickstein. Even know we are working on Opportunity, he was looking at the tracks of Spirit. He said “They seem to stand up pretty well, they don’t fall apart.” There are several theories to that fact. One is that because the gravity of Mars isn’t as strong, so the influence of static is stronger and that holds the soil together. But to prove that, we’d have to observe the length of time that the soil stuck to the wheels. The other thing we looked at were the blueberries. Scientists came up with theories of what they were and it’s funny because they know as much as we do about them! It could be either the erosion of water that rounded the particles, or the lava spit of volcanoes that eventually rounded in air and cooled before it touched ground; or something else. Before the science downlink assessment meeting, Matt showed us curves and zigzags in the layers of rocks. On top and below the layers, there are smooth straight layers. During the Science Downlink Assessment Meeting, Steve Squyres, the chair, announced the star of today’s meeting, the soil and rock physical properties group. He declared that next sol would be a great sol for Microscopic Imager (MI). Bob Anderson created a sequence to use the MI to study the outcrop. He showed the sequence and said “You told me to be aggressive, so that’s 18 MIs. Did that blow you off your chair?” “Well, I was expecting more,” said Steve. So Bob immediately added another series of MI above and below the ones he’d sequenced before. That’s like the most MIs I’ve ever seen in any sol! Even though the MIs take most of the time, there is time for other analysis too. The RAT lead Steve Gorevan hopes to RAT the outcrop in the future. He said, “If the material is chalky, we could end up with a 10 mm hole!” The normal holes are about 1 or 2 mms deep! After the meeting, we met Robert Manning, one of the top engineers on the mission. He explained what the future route of the rover could be: “crater hopping.” He showed us the images taken of the landing site by Mars Global Surveyor (MGS). He hopes they will be able to move towards the back shell of the rocket. We could look at the colors of heating, the burn marks. The resolution of the MGS images is incredible. It is done by a method called Super Resoultion. Taking a bunch of pictures from different angles and putting them together into a picture can give resolutions a camera can’t reach by one picture They did the same thing with Pathfinder with the Twin Peaks area. As I was typing the journal Jim Erickson came in to our cubicle! He is Mission Manager of the Mars Exploration Rovers, but he also worked on previous missions like Voyager, Viking and Galileo. At the Science Operations Working Group meeting, the whole point of the meeting soon turned into what sequences to kill. There are data, duration, and energy constraints. So only the most important sequences get to survive. At the End of Sol meeting, there was a presentation of sky temperature observations. The scientist compared the temperatures at Gusev and Meridiani. There was another presentation about the features found on rocks. Today was the most eventful day I had at JPL. It’s unbelievable that so many events could be compressed into one sol. Spirit Sol 48 / Opportunity Sol 28Saturday, February 21, 2004 Today we went to the context meeting with Camillia, Nomathemba, Kristyn and KJ. It's sol 28 planning for 29. The mineralogy group gave a brief presentation on common mineralogical terms, and, scientists shared images returned from the Microscopic Imager. The pictures are very interesting. At the end of the meeting, a scientist demonstrated a 3d image and invited all of us to fly it around after the meeting. One scientist explained how these images were made. It's similar to the maestro software. "There are two pan cams and each pan cam is like the human eye. Our eyes tell us far a thing is away from us. Our brain does this calculation all the time and figures out the distance. We're doing the same thing here for the rover. We put two pictures taken form the right and left eye together. Then the computer would figure out the same feature in the two pictures that are taken from different angles. This is called the correlation of pixels. Whenever it finds the same pixels, it would be create a point. By the end of the process, there will be a point cloud. This gives us the skeleton of the 3D image. Then we stretch the picture over it. It shows the texture of the rocks." As we took turns flying over the image, Kristyn switched over to the skeleton mode and found a bunch of triangles. Then he continued, "The angles of the triangles are the magic correlation points. And as we zoomed out, the image sort of bulged around. That subtle movement of the image is the result of the adjust process. The computer only shows the amount of triangles that changes with the distance. If you zoom in, there would be more triangles, if you zoom out, there would be less triangles. This adjustment helps the computer run smoothly. This method is often adopted in 3D computer games." Then she clicked a button and suddenly we saw red lines that boxed parts of the image. "Those bounding boxes", he explained, " shows the pair of images that are bound together. This is the same method that the Navcams adopt to create 3D images." My experience at JPL is incredible. It's like squeezing all the fun into few tight days. Kristyn and I got to hold a RAT, an actual part of the rover. We also saw the rovers and landing platform in real size at the test bed. The media also interviewed us. Meeting all the Star Trek movie stars and taking pictures with them and getting their autographs was fascinating. We also ran through the meetings and talked a lot of the engineers and the scientists to and understood what a rovers day is like. Spirit Sol 49 / Opportunity Sol 29Sunday, February 22, 2004 When I walked into JPL today with Kristyn, Camillia, Nomathemba and Joe, we saw deer grazing on the grass of JPL! Three deer took their slow afternoon walk here. They don't show the slightest sign of fear. We took pictures of them. I'm surprised how many wild animals hang around JPL. The center of so many space explorations is actually so close to nature. Last week we saw a squirrel up the tree. They think they own this place. Before the science context meeting, I got to fly over some 3D images again. This time, I wore 3D glasses. I think it makes the image even more realistic. Some scientists were looking at them with Matt Golombek, one of the scientists that chose the landing site. The 3D glasses I wore aren't those glasses with blue and red filters over them; they are normal glasses. When I put them on, the left and right lenses took start flashing. It was really cool. The rover is reaching the 30-day minimum success period. The scientists are expecting more mission success standards to be met soon. They looked at the cross bedding of the outcrop. We went upstairs to do some image calibrating. The new Marsdial soft ware that we used was sort of buggy, so the time of some images couldn't be processed. Kristyn and I taught Camillia and Nomathemba, the next and last group of student astronauts, about the three projects we are working on. They are the dust project, image calibration, and finding time on the Marsdials. The dust project checks the accumulation of dust by looking at its values between the shaded part and not shaded parts. The image calibration calibrates the image for the two projects. And the purpose of finding time on Mars with the Marsdial is to cross check with the clock on the rover. Walter Goetz, the scientist on the magnet team came in and said goodbye to Kristyn and I. He explained functions of the magnet next to the Marsdial. The ring shaped magnet is specially designed so that the magnet attracts any dust with the slightest magnetic composition near the ring. Only the non-magnetic dust falls into the center of the ring. It's a long-term thing to learn about. What's the percentage of the dust on Mars that has magnetic compositions? Walter also explained that dust accumulation will eventually stop the rovers. The battery will degrade and the sun will be moving away from Mars by the end of the mission. The orbit of Mars is more elliptical so the sun would be pretty far away. The perihelion and aphelion are the two points when Mars is at its furthest and closest points away from the sun in its orbit. We went to Mission Operations and met Bob Anderson. He explained what he was doing. He is in charge of data downlink. The products (images or spectrums) are sent to Earth in packages. Then he turns the packages back into products. The rover sends an event record (EVR) to earth before the products are even received. So it sends messages like "I'm beginning to RAT" or "I'm halfway done with the Mossbauer" or "I just took the Pancam images" before he gets the images. He said that there two or three direct communication passes with the rover plus the Mars Odyssey and Mars Global Surveyor (MGS) passes. "The MGS or Odyssey sends signals to the rover and once the rover hears the signal, it uplinks all the data it can during the period of the pass." The Science Downlink Assessment Meeting was, as always, very interesting. "It's going to be a RAT day," said Steve Squyres. "No other instrument can operate during the ratting process." There are different opinions about the ratting parameters. Someone wants to go with more aggressive parameters. His opinion is based on the hardness of the rock and the performance of the RAT. Some scientists think it's a great day to work on the flash memory. While others plan for a run-out sequence, which has a very low chance of use in next sols sequence. Run out sequences are sequences the rover does if, for some reason, it doesn't get commands from Earth for what to do next sol. The experience at JPL is amazing. It excites me every time I remind myself that there is a real Mars exploration mission out there on Mars. Someday I might look back in time and say "I not only saw the historic moment of the mission, but actually played a role in the Mars Exploration Rover." |
||||||
 |
 |
||||||
[ what is this? ]