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The Soil Moisture Active Passive (SMAP) Mission


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The Soil Moisture Active Passive (SMAP) mission is one of the Tier 1 missions recommended by the U.S. National Research Council Committee on Earth Science and Applications from Space for launch as early as possible in the 2010-2019 decade ("Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond," National Academies Press, 2007).  SMAP was successfully launched on January 31, 2015 from Vandenberg Air Force Base onboard a Delta II launch vehicle.  It has currently reached its science orbit and configuration (spinning at 14.6 rpm at an altitude of 685 km, enabling global mapping of soil moisture and freeze-thaw state every 2-3 days).  The SMAP observatory and instruments are in the final stages of their on-orbit checkout, with routine science operations scheduled to begin in early May, 2015 as the SMAP Project enters into a year-long period to calibrate and validate all SMAP data products.  SMAP data products are generated within the project's Science Data System and are made available publicly through two NASA-designated data centers, the Alaska Satellite Facility (ASF) and the National Snow and Ice Data Center (NSIDC).
SMAP uses a 1.4 GHz microwave radiometer, a high-resolution 1.2 GHz radar, and a combination of the two instruments to measure surface soil moisture and freeze-thaw state, providing new opportunities for scientific advances and societal benefits.  Direct measurements of soil moisture and freeze-thaw state will aid understanding of regional and global water cycles, ecosystem productivity, and the processes that link the water, energy, and carbon cycles.  Soil moisture and freeze-thaw state information provided by SMAP at high resolution will also enable improvements to weather and climate forecasts, flood prediction and drought monitoring, and measurement of net CO2 uptake in forested regions.