After a five-year delay, an Earth-observing satellite will be launched to test new technologies aimed at improving weather forecasts and monitoring climate change. The $1.5 billion NASA mission comes in a year of weather extremes from the Midwest tornado outbreak to the Southwest wildfires to hurricane-caused flooding in New England. "We've already had 10 separate weather events, each inflicting at least $1 billion in damages," said Louis Uccellini of the National Oceanic and Atmospheric Administration. The satellite will lift off before dawn Friday from Vandenberg Air Force Base, California, aboard a Delta 2 rocket that will boost it into an orbit some 500 miles (800 kilometers) high. The space agency already has a fleet of satellites circling the Earth, taking measurements of the atmosphere, clouds and oceans. But many are aging and need replacement.