T Minus Zero
The SMAP observatory was launched into space on 31 January 2015 from California's Vandenberg Air Force Base, marking the beginning of its three-year mission.
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Onlookers gather in early morning to watch the SMAP observatory as it is rocketed to its new home in space. Once there, it will measure surface soil moisture and its freeze/thaw state.
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Mapping Moisture
SMAP measures soil moisture across the entire Earth every three days, creating maps that help forecast crop productivity, and the risk of floods, drought, wildfires, and vector-borne diseases.
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All Systems are Go
SMAP’s most prominent feature is its large spinning instrument antenna. Its gold-plated wire mesh surface focuses the radio frequency energy collected by SMAP’s radar and radiometer.
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Launch photo
Rocket viewed from the ground
Moisture map


The NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) and the NASA Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC) jointly manage SMAP science data on behalf of the NASA ESDIS Project. The NSIDC DAAC distributes validation campaign data and science data for the SMAP mission, including Level-1 through Level-4 radiometer data, Level-2 and Level-3 radar and combined radar/radiometer data, and Level-4 radiometer data. SMAP Level-1 radar data are available at the ASF DAAC.

About the Instrument

Launched on 31 January 2015, the SMAP instrument includes a radiometer and a high-resolution radar to measure surface soil moisture and freeze-thaw state. The instrument was designed to make coincident measurements of surface emission and backscatter, and to sense soil conditions through moderate vegetation cover. With a swath width of 1,000 km, SMAP provides global coverage within three days at the equator and two days at boreal latitudes (greater than 45 degrees N).

Although the SMAP L-Band Radar failed on 07 July 2015, it succeeded in mapping global polarimetric backscatter over a thirteen week period. The SMAP L-Band Radiometer continues to operate as planned. For more information regarding the instrument failure, refer to the SMAP News Release issued by the Jet Propulsion Laboratory (JPL). For access to all SMAP radar and radiometer data, visit the SMAP Data page.

About the Mission

The primary science objective of SMAP is to create global, high-resolution mapping of soil moisture and its freeze/thaw state with unprecedented accuracy, resolution, and coverage to:

  • link terrestrial water, energy, and carbon cycle processes
  • estimate global water and energy fluxes at the land surface
  • quantify net carbon flux in boreal landscapes
  • extend weather and climate forecast capabilities
  • develop improved flood and drought prediction capability
  • develop improved agricultural productivity and climate change prediction capability