VANDENBERG AIR FORCE BASE, Calif. - Six weather satellites successfully reached orbit and were ready to begin their five-year mission to track hurricanes, monitor climate change and study space weather, it was announced Saturday.

"Ground stations have received signals from all six satellites," according to an update on the Web site for the project's manager, University Corporation for Atmospheric Research in Boulder, Colo.

The satellites were launched on a rocket booster Friday evening from this Central Coast base. They were placed into orbit about 500 miles above Earth, where they separated to form a chain.

The satellites will take about 2,500 daily measurements by using global positioning receivers to track radio signals passing through the atmosphere, scientists said.

The information gathered will be used to enhance research and improve weather forecasting. Scientists hope the data will help them better track storms and monitor long-term climate change.

The satellites, which weigh 155 pounds each and are 40 inches long, are equipped with three instruments including a GPS radio receiver, a photometer and a beacon to relay data to ground station on Earth.

The $100-million mission was funded by Taiwan and several U.S. agencies including the National Science Foundation.

The mission is known as COSMIC in the United States and FORMOSAT-3 in Taiwan. COSMIC stands for Constellation Observing System for Meteorology, Ionosphere and Climate.

ON THE NET

COSMIC mission: http://www.cosmic.ucar.edu