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  • Date :
  • 2/18/2007

NASA launches five-satellite rocket

Story Highlights

• NEW: Themis science satellites lifted into orbit

• Probes will study geomagnetic sub-storms in the Earth's atmosphere

• Storms damage communications satellites, disable power grids

• Five satellites are most NASA has put on one rocket

Launch boosters are jettisoned from a Titan 2 rocket as it lifts a NASA science project into orbit Saturday.

CAPE CANAVERAL, Florida (AP) -- A Delta 2 rocket lifted five NASA science satellites into space Saturday evening from Cape Canaveral Air Force Station.

The launch was delayed by one day because of high upper-level winds.

"The strong winds would have affected the rocket's path," said Rani Gran, a NASA spokeswoman.

The probes are all part of a mission to figure out the source of powerful geomagnetic sub-storms in the Earth's atmosphere.

Scientists hope the $200 million mission unravels the mystery behind these 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. (NASA's mission Web page)

Scientists believe they also periodically intensify the spectacular light shows seen in the northern lights, or aurora borealis.

"For 30 years, people have tried to understand what causes the onset of these sub-storms," said Vassilis Angelopoulos of the University of California, Berkeley, principal investigator for the Themis mission. "Finding out the origin ... has been so elusive."

If all goes as planned, it will be 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 micro-satellites on one rocket.

The five Themis probes will separate from the Delta 2 rocket more than an hour after launch. After separation, scientists at a UC-Berkeley ground station will begin initiating signals with each satellite.

If successful, the mission will end the debate scientists hold as to when the sub-storms are triggered.

One theory holds that the sub-storms start about 50,000 miles above the Earth's equator, about a sixth of the way to the moon, when the electromagnetic turbulence disrupts the flow of intense space currents.

The other theory is that the sub-storms are triggered about 100,000 miles above the equator with the spontaneous conversion of magnetic energy into heat. Particle acceleration then triggers the sub-storm energy.

"This is how we're going to utilize four out of the five probes, to nail that timing question and resolve the location question, and distinguish between the two competing theories," Angelopoulos said.


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