The story appears on

Page A10

August 31, 2012

GET this page in PDF

Free for subscribers

View shopping cart

Related News

HomeWorld

Satellites will probe Earth's dangerous radiation belts

TWIN satellites rocketed into orbit yesterday on a quest to explore Earth's treacherous radiation belts and protect the planet from solar outbursts.

NASA launched the science probes before dawn, sending them skyward aboard an unmanned rocket. "We're all thrilled, just as excited as can be," said launch director Tim Dunn.

It's the first time two spacecraft will orbit in tandem amid the punishing radiation belts of Earth, brimming with highly charged particles capable of wrecking satellites.

These new satellites - shielded with thick aluminum - are designed to withstand an onslaught of cosmic rays for two years.

"We're going to a place that other missions try to avoid and we need to live there for two years. That's one of our biggest challenges," said Richard Fitzgerald, project manager for the Johns Hopkins University Applied Physics Laboratory, in the US state of Maryland, next to Washington, DC. The lab built the Radiation Belt Storm Probes for NASA.

Scientists expect the US$686 million mission to shed light on how the sun affects the Van Allen radiation belts, named after the astrophysicist who discovered them a half-century ago.

Earth's two doughnut-shaped radiation belts stretch thousands of kilometers into space; these inner and outer belts are full of high-energy particles from the sun and elsewhere in the cosmos, and are trapped by the Earth's magnetic field.

Normally, the belts remain well above the International Space Station and low-flying satellites. But the belts can expand during solar storms right into the paths of orbiting spacecraft. If severe enough, the storms can cripple satellites and endanger astronauts, and disrupt power and communications on the ground.

The goal of this mission is to improve space weather forecasting.

"The Earth responds to what's coming from the sun, so we say, 'If the sun sneezes, the Earth catches a cold,' " said Nicola Fox, deputy project scientist for Johns Hopkins. The symptoms vary widely and need to be better understood, she said.

Science instruments aboard the nearly identical spacecraft are designed to measure the high-energy particles coursing through the radiation belts and numbering in the trillions.


 

Copyright 漏 1999- Shanghai Daily. All rights reserved.Preferably viewed with Internet Explorer 8 or newer browsers.

娌叕缃戝畨澶 31010602000204鍙

Email this to your friend