By Irene Klotz
CAPE CANAVERAL, Fla. (Reuters) - - An unmanned Delta 2 rocket lifted off from California on Saturday carrying a NASA satellite to measure moisture in the top layer of the Earth's soil, data to be used in weather-forecasting and tracking of global climate change.
Soil moisture is a variable that binds together all of the planet's environmental systems, scientists say. More precise data will enable forecasters and policy-makers to deal more effectively with drought or flooding in specific regions. "It's the metabolism of the system," said Dara Entekhabi, lead scientist of NASA's Soil Moisture Active Passive (SMAP) observatory.
The 127-foot (39 meter) rocket, built and flown by United Launch Alliance (ULA), blasted off at 6:22 a.m. PST (9 a.m. ET) from Vandenberg Air Force Base, located on California's central coast, a live NASA Television broadcast showed.
ULA is a partnership of Lockheed Martin Corp and Boeing Co. The launch had been delayed for two days by high winds and the need to make minor repairs to the rocket's insulation.
Perched on top on the rocket was NASA's 2,100-pound (950 kg) SMAP, which will spend at least three years measuring the amount of water in the top 2 inches of Earth's soil.
Overall, soil moisture accounts for less than 1 percent of the planet's total water reservoir, with 97 percent in the planet's oceans and nearly all of the rest locked in ice, Entekhabi, a professor at the Massachusetts Institute of Technology, said at a pre-launch news conference.
Currently, scientists rely largely on computer models to estimate soil moisture. But from an orbit 426 miles (685 km) above Earth, SMAP has two microwave instruments to collect exact soil moisture measurements everywhere on Earth and update the measurements every two or three days.
"This data will benefit not only scientists seeking better understanding our planet's climate environment, but it's also a boon for weather forecasters, agriculture and water resource managers, emergency planners and policy makers," NASA deputy associate administrator Geoffery Yoder, said after the launch.
SMAP joins 19 other NASA satellites keeping tabs on Earth's land, seas and atmosphere.
"We strive to give the world a consistently expanding view and understanding of our planet from space," Yoder said.
Including the rocket launch and three years of operations, the SMAP mission will cost NASA $916 million.