WASHINGTON, Oct. 15, 2014 /PRNewswire-USNewswire/ -- A NASA spacecraft designed to track Earth's water in one of its most important, but least recognized forms -- soil moisture -- now is at Vandenberg Air Force Base, California, to begin final preparations for launch in January. The Soil Moisture Active Passive (SMAP) spacecraft arrived Wednesday at its launch site on California's central coast after traveling from NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. The spacecraft will undergo final tests and then be integrated on top of a United Launch Alliance Delta II rocket in preparation for a planned Jan. 29 launch.

SMAP will provide the most accurate, highest-resolution global measurements of soil moisture ever obtained from space and will detect whether the ground is frozen or thawed. The data will be used to enhance scientists' understanding of the processes that link Earth's water, energy and carbon cycles. Soil moisture is critical for plant growth and supplies aquifers, which are underground water supplies contained in layers of rock, sand or dirt.

Through evaporation, water in the soil cools the land surface and lower atmosphere while seeding the upper atmosphere with moisture that forms clouds and rain. High-resolution global maps of soil moisture produced from SMAP will allow scientists to understand how regional water availability is changing and inform water resource management decisions.