NASA Facts National Aeronautics and Space Administration Jet Propulsion Laboratory California Institute of Technology Pasadena, CA 91109 Exploration Rover In 2003, two powerful new Mars rovers will be all their instruments with them. Immediately after on their way to the red planet. With far greater landing, the rover will begin reconnaissance of the mobility than the 1997 Mars Pathfinder rover, these landing site by taking a 360-degree visible color and robotic explorers will be able to trek up to 100 infrared image panorama. It will then leave the petal meters (about 110 yards) across the surface each structure behind, driving off to begin its exploration. day. Each Mars 2003 rover will carry a sophisticated set of instruments that will allow it to Using images and spectra taken daily from the search for evidence of liquid water that may have rovers, scientists will command the vehicle to go to been present in the planet's past. The rovers will be rock and soil targets of interest and evaluate their identical to each other, but composition and their tex- will land at different ture at microscopic scales. regions of Mars. Initial targets may be close to the landing sites, but Mission Overview later targets can be far Both rovers are afield: These exploration planned for launch from rovers will be able to trav- Cape Canaveral, Florida, el almost as far in one one on June 3, 2003, and Martian day as the the second on June 27. Sojourner rover did over The first should reach its entire lifetime. Mars January 4, 2004, the other on February 25. Rocks and soils will The landing for each will be analyzed with a set of resemble that of the five instruments on each Pathfinder spacecraft. A rover, and a special tool parachute will deploy to slow the spacecraft and called the rock abrasion tool, or “RAT,” will be used airbags will inflate to cushion the landing. Upon to expose fresh rock surfaces for study. Each rover reaching the surface, the spacecraft will bounce about has a mass of nearly 150 kilograms (about 300 a dozen times, and could roll as far as one kilometer pounds) and has a range of up to 100 meters (about (0.6 mile). When it stops, the airbags will deflate 110 yards) per , or Martian day. Surface opera- and retract and the petals will open up, bringing the tions will last for at least 90 sols, extending to late lander to an upright position and revealing the rover. April 2004, but could continue longer, depending on the health of the vehicles. The landed portion of the mission features a design dramatically differ- Science Goals ent from Mars Pathfinder's. Where Pathfinder had The mission seeks to determine history of cli- scientific instruments on both the lander and the mate and water at a two sites on Mars where condi- small Sojourner rover, these larger rovers will carry tions may once have been favorable to life. The sites will be chosen by about a year before launch, on the dance of many different kinds of minerals. A particu- basis of intensive study of orbital data collected by lar goal will be to search for distinctive minerals that the Mars Global Surveyor spacecraft and other mis- are formed by the action of water. Scanning to build sions. Selection criteria will include clear evidence of up a panoramic image, it will also be used in tandem ancient water, as indicated either by minerals that with the Panoramic Camera to select science targets form under wet conditions or landscapes apparently and to pick new areas to explore. shaped by water. Possibilities include former lakebeds or hydrothermal deposits. The rovers' l Mössbauer Spectrometer: Identifying Iron- instruments will be used to read the geologic record Bearing Minerals at the sites, and to evaluate how suitable the past con- This instrument will be placed against rock and ditions would have been for life. soil targets by an arm on the rover. It will identify any minerals that contain iron, help to evaluate what Science Instruments role water played in the formation of these minerals, Each rover will carry five scientific instruments and help to discern the extent to which rocks have and an abrasion tool: a Panoramic Camera provided been weathered. by NASA's Jet Propulsion Laboratory, Pasadena, Calif.; a Miniature Thermal Emission Spectrometer l Alpha Proton X-Ray Spectrometer: Determining from Arizona State University, Tempe, Ariz.; a the Composition of Rocks Mössbauer Spectrometer from the Johannes This instrument is an improved version of the Gutenberg University, Mainz, Germany; an Alpha- instrument used by Pathfinder's Sojourner rover. It Proton X-ray Spectrometer from Max Planck measures the concentrations of most major elements, Institute for Chemistry, also in Mainz, Germany; and allowing investigation of how rocks and soils formed a Microscopic Imager from JPL. The Rock Abrasion and how they have been altered over time. Tool provided by Honeybee Robotics, New York, N.Y., will grind away the outer surfaces of rocks, l The Microscopic Imager: Looking at Fine-scale which may be dusty and weathered, allowing the sci- Features ence instruments to determine the nature of rock inte- This instrument will reveal fine-scale appearance riors. The payload also includes magnetic targets pro- of rocks and soils, which can provide essential clues vided by Niels Bohr Institute in Copenhagen, to how those rocks and soils were formed. For Denmark. The spectrometers, microscopic imager instance, the size and angularity of grains in water- and abrasion tool will be deployed on a robotic arm. lain sediments can reveal how they were transported and deposited. l Panoramic Camera: Providing the Geologic Context Project/Program Management This instrument will be used to reveal the terrain The Mars Exploration Rover is managed for around the rover, searching for evidence of the action NASA by the Jet Propulsion Laboratory, a division of of liquid water. It will be used to help select the most the California Institute of Technology, Pasadena, promising rock and soil targets for more intensive Calif. At NASA Headquarters, David Lavery is the study, and to pick new regions for the rover to program executive and Dr. Catherine Weitz is the explore. Its resolution is over three times better than program scientist. At JPL, Peter Theisinger is the that of the cameras carried on the Mars Pathfinder project manager and Dr. Joy Crisp is the project sci- lander. entist. The principal investigator for the science pay- load is Dr. Steve Squyres from Cornell University, l Miniature Thermal Emission Spectrometer: Ithaca, N.Y. Identifying Minerals at the Site This instrument will view the scene around the 10-24-2000 rover in the infrared, determining types and abun-

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