Satellites launch to study substorms

Five science satellites blasted off on a single rocket into a golden sunset Saturday on a mission to figure out the source of powerful geomagnetic substorms in the Earth’s atmosphere.

The launch at 6:01 p.m. from the Cape Canaveral Air Force Station came after strong upper winds forced a delay of 24 hours, said Rani Gran, NASA spokeswoman.

Scientists hope the $200-million Themis mission unravels the mystery behind the storms that can damage communications satellites, disable power grids and shoot high levels of radiation down on spacewalking astronauts and airplane passengers flying over northern latitudes.

Scientists believe the storms also periodically intensify the northern lights.

“For 30 years, people have tried to understand what causes the onset of these substorms,” said Vassilis Angelopoulos of UC Berkeley, principal investigator for the mission. “Finding out the origin ... has been so elusive.”

It is the most probes NASA has ever launched on a single rocket. However, last year a joint venture of Taiwan and the U.S. National Science Foundation launched six weather microsatellites on one rocket.

Little more than an hour after blastoff, the probes separated from a Delta II rocket. About two hours after launch, scientists at a UC Berkeley ground station initiated signals with each probe, officials said.

Each satellite will magnetically map North America every four days for about 15 to 20 hours in tandem with 20 ground stations. Scientists plan to begin receiving data from the probes in about two months and continue receiving information for many years, officials said.