NASA has successfully launched its groundbreaking Soil Moisture Active Passive observatory (SMAP) at 15:22 UTC today. SMAP is the first Earth satellite designed to collect global observations of the vital soil moisture hidden just beneath our feet. Its high resolution space-based measurements of soil moisture will give scientists a new capability to better predict natural hazards of extreme weather and improve our understanding of Earth’s water, energy and carbon cycles.
The first public release of SMAP soil moisture data products is expected within 9 months. Fully validated science data are expected to be released within 15 months.
About 57 minutes after liftoff, SMAP separated from the rocket's second stage into an initial 661- by 685-kilometer (411- by 425-mile) orbit. After a series of activation procedures, the spacecraft established communications with ground controllers and deployed its solar array.
SMAP will orbit Earth from pole to pole every 98.5 minutes, repeating the same ground track every eight days. Its 1000 (620-mile) measurement swath allows SMAP to cover Earth's entire equatorial regions every three days and higher latitudes every two days. The mission will map global soil moisture with about 9-kilometer (5.6-mile) resolution.
SMAP will now begin a three-year mission that will figuratively scratch below Earth's surface to expand our understanding of a key component of the Earth system that links the water, energy and carbon cycles driving our living planet.
SMAP's combined radar and radiometer instruments will peer into the top 5 centimeters (2 inches) of soil, through clouds and moderate vegetation cover, day and night, to produce the highest-resolution, most accurate soil moisture maps ever obtained from space.
The mission will help improve climate and weather forecasts and allow scientists to monitor droughts and better predict flooding caused by severe rainfall or snowmelt - information that can save lives and property.
In addition, since plant growth depends on the amount of water in the soil, SMAP data will allow nations to better forecast crop yields and assist in global famine early-warning systems.
SMAP also will detect whether the ground is frozen or thawed. Detecting variations in the timing of spring thaw and changes in the length of the growing season will help scientists more accurately account for how much carbon plants are removing from Earth's atmosphere each year.
"The launch of SMAP completes an ambitious 11-month period for NASA that has seen the launch of five new Earth-observing space missions to help us better understand our changing planet," said NASA Administrator Charles Bolden. "Scientists and policymakers will use SMAP data to track water movement around our planet and make more informed decisions in critical areas like agriculture and water resources."
During the next 90 days, SMAP and its ground system will be commissioned to ensure they are fully functional and are ready to begin routine science data collection. A key milestone will be the deployment of the spacecraft's instrument boom and 6-meter-diameter (20-foot) reflector antenna. The observatory will be maneuvered to its final 685-km (426-mile), near-polar operational orbit, and the antenna will spin up to 14.6 revolutions per minute. Its science operations will then begin.
The mission will make science data products available to the public through two NASA-designated Earth science data centers, the Alaska Satellite Facility (for Level 1 radar products) and the National Snow and Ice Data Center (for all other products).
SMAP will coordinate the release of data product versions with the data center and will ensure the completeness and accuracy of quality control information and validation status of the data products. There will be a calibration and validation (Cal/Val) phase during the science mission that will follow the 90-day post launch in-orbit commissioning (IOC) phase. The duration of the Cal/Val phase is 6 months for Level 1 products and 12 months for Level 2 through Level 4 products.
The initial "beta" release of Level 1 products will take place 3 months after IOC. Level 2 to Level 4 beta products will be released 6 months after IOC. At the end of the Cal/Val phase the goal is for data products to have attained the level of "validated".
SMAP's Delta II rocket also carried a JPL CubeSat into orbit. The GRIFEX (Geostationary Coastal and Air Pollution Events Read-Out Integrated Circuit In-Flight Performance Experiment) CubeSat was one of three NASA-sponsored CubeSat missions successfully deployed during the launch. About the size of a loaf of bread, GRIFEX will validate cutting-edge detector technology for use in future Earth-observing satellites.
Featured image: NASA/Bill Ingalls