Published: Oct 28, 2011 12:23 PM EDT

VANDENBERG AIR FORCE BASE, Calif. (AP) - After a years-long delay, an Earth-observing satellite blasted into space early Friday on a dual mission to improve weather forecasts and monitor climate change.
 
A Delta 2 rocket carrying the NASA satellite lifted off shortly before 3 a.m. from the central California coast. The satellite was boosted into an orbit 500 miles above Earth about an hour after launch.
 
NASA invited a small group of Twitter followers to watch the pre-dawn launch from Vandenberg Air Force Base.
 
The satellite joins a fleet already circling the planet, collecting information about the atmosphere, oceans and land. The latest - about the size of a small SUV - is more advanced. It carries four new instruments capable of making more precise observations.
 
 
Meteorologists will use the data to improve their forecasts of hurricanes and other extreme weather while climate researchers hope to gain a better understanding of long-term climate shifts.
 
Many satellites currently in orbit are aging and will need to be replaced. The newest satellite is intended to be a bridge between the current fleet and a new generation that NASA is developing for the National Oceanic and Atmospheric Administration.
 
The $1.5 billion mission's path to the launch pad has been rocky. It was originally scheduled to fly in 2006, but problems during development of several instruments led to a delay.
 
Engineers will spend some time checking out the satellite's instruments before science operations begin. Built by Ball Aerospace & Technologies Corp. in Boulder, Colo., the satellite is expected to orbit the Earth for five years.