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PASSPORT TO KNOWLEDGE - To MARS with MER
When the going gets tough, the tough get going.
When the going gets tough, the tough get going. That's what's happening now at NASA JPL: as if landing a second spacecraft, Opportunity, on Mars were not difficult enough, the Mars Exploration Rover team is experiencing serious difficulties with Spirit, already on the ground at Gusev Crater. Spirit was going to be given a planned rest during Opportunity's landing and first days on the surface -- though this kind of spell of "intensive care" was in no-one's play book -- in order to allow full attention to today's inherently risky events. But the Jan 23 briefing was evidence of the quality and commitment of the mission team: project manager, Pete Theisinger, was calm and forthcoming: yes, there were serious communications and possibly hardware problems with the spacecraft (see JPL releases linked in below) but a dedicated team of engineers was carefully working through data to come up with answers, while a separate team was attending to the Entry, Descent and Landing, or EDL, of Opportunity (set for the evening of Saturday Jan 24, Pacific time.) Most of the questions, naturally, were about Spirit, which unfortunately eclipsed the amazing information and images in the reports of Wayne Lee, Miguel San Martin and Adam Steltzner: for the past few weeks, they and colleagues have been working on a "reconstruction" of Spirit's EDL, in order to fine tune that for Opportunity. They've been able to get to incredible detail, including data that the Descent Rate Limiter (controlling the unspooling of the bridle linking the lander to the backshell) took 11 not the expected 6 seconds to deploy. Their information about the number and direction of the bounces also allowed them to determine exactly where Spirit came to rest: equally astonishing images from the Mars Orbital Camera aboard the Global Surveyor allowed MOC camera PI, Mike Malin, to show where the parachute and backshell, the heat shield, and Spirit herself came to rest. Check out the images for evidence of how powerful the combination of software, hardware and human ingenuity can be. Spirit's communications difficulties are serious and as yet mysterious: not even Pete Theisinger could predict if and when progress might be made. But the Rover mission team are tough and dedicated: if anyone can figure out the problems and fix them, it's them. Stay tuned for news from Opportunity and soon, we hope, once more from Spirit.
Scientists Thrilled to See Layers in Mars Rocks Near Opportunity
January 27, 2004
New pictures from NASA's Mars Exploration Rover Opportunity reveal thin layers in rocks just a stone's throw from the lander platform where the rover temporarily sits.
Geologists said that the layers -- some no thicker than a finger -- indicate the rocks likely originated either from sediments carried by water or wind, or from falling volcanic ash. "We should be able to distinguish between those two hypotheses," said Dr. Andrew Knoll of Harvard University, Cambridge, a member of the science team for Opportunity and its twin, Spirit. If the rocks are sedimentary, water is a more likely source than wind, he said.
Image Credit: NASA/JPL/Cornell University
The prime goal for both rovers is to explore their landing areas for clues in the rocks and soil about whether those areas ever had watery environments that could possibly have sustained life.
Controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., plan to tell Opportunity tonight to start standing up from the crouched and folded posture in which it traveled to Mars.
"We're going to lift the entire rover, then the front wheels will be turned out," said Mission Manager Jim Erickson of JPL. Several more days of activities are still ahead before the rover will be ready to drive off the lander.
"We're about to embark on what could be the coolest geological field trip in history," said Dr. Steve Sqyures of Cornell University, Ithaca, N.Y., principal investigator for the rovers' science payload.
The layered rocks are in a bedrock outcrop about 30 to 45 centimeters (12 to 18 inches) tall, and only about eight meters (26 feet) away from where Opportunity came to rest after bouncing to a landing three days ago. Examination of their texture and composition with the cameras and spectrometers on the rover may soon reveal whether they are sedimentary, Knoll predicted.
Scientists also hope to determine the relationship between those light-colored rocks and the dark soil that covers most of the surrounding terrain. The soil may contain the mineral hematite, which was identified from orbit and motivated the choice of Opportunity's landing area, Squyres said.
Opportunity successfully used its high-gain antenna for the first time yesterday. The rover is losing some if its battery charge each night, apparently due to an electric heater at the shoulder joint of the rover's robotic arm. A thermostat turns on the heater whenever the air temperature falls to levels that Opportunity is experiencing every night. The heater is not really needed when the arm is not in use, but ground control has not been able to activate a switch designed to override the thermostat, Erickson said. Mission engineers are working to confirm the diagnosis, determine the ramifications of the power drain, and propose workarounds or fixes.
Meanwhile, engineers working on Spirit have determined that the high- gain antenna on that rover is likely in working order despite earlier indications of a possible problem. They are continuing to take information out of Spirit's flash memory. Results from a testbed simulator of the rover's electronics supported the diagnosis of a problem with management of the flash memory, reported JPL's Jennifer Trosper, mission manager.
JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA's Office of Space Science, Washington, D.C. Images and additional information about the project are available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University at http://athena.cornell.edu.