Scientists open an eye on the sun

Antarctica: After years of setbacks, a team from Johns Hopkins has sent aloft a telescope it hopes will help unravel the mysteries of solar flares.

January 11, 2000|By Douglas Birch | Douglas Birch,SUN STAFF

MCMURDO STATION, Antarctica -- After years of setbacks and weeks of delays, scientists from Johns Hopkins University's Applied Physics Laboratory launched a mammoth balloon here yesterday carrying their star-crossed solar telescope.

Displaying the endurance that this continent requires of explorers, the Hopkins team and its leader, physicist David M. Rust, overcame technical problems and began capturing the first images on tapes aboard the balloon's gondola.

Although the pictures won't be retrieved for several weeks, the launch of the Flare Genesis Telescope brought Rust one step closer to fulfilling his dream of creating the sharpest images ever of the sun.

In late afternoon, with the temperature hovering around 14 degrees, Rust watched the telescope -- about the size of a minivan -- soar into the thin Antarctic air.

"Wow," said Rust, 60, of Silver Spring, staring up through his ski goggles. "Straight up over us."

The APL team just made it. If the balloon hadn't been launched by Friday, the team would have had to cancel the flight, pack up the telescope and head back to Maryland having accomplished nothing.

Rust studies solar flares, violent eruptions of radiation and atomic particles that billow from the surface of the sun. Solar flares might occur, he says, when the magnetic fields that lace the sun's surface kink and snap like over-twisted rubber bands. Or they might happen when old magnetic fields abruptly connect to new magnetic fields emerging from the sun's interior. No one is sure.

But sharper pictures of the events, he said, could explain the mysterious mechanisms behind these violent events. They could also help revive interest in solar research, which he said has been in the doldrums for more than a decade. (The Hubble Space Telescope, for example, cannot look at the sun.)

As Rust points out, the sun is the only star that has any significant effect on Earth. Solar storms can interrupt radio and television transmissions or threaten the lives of astronauts. A 1989 storm knocked out power across Quebec and probably gave some airline passengers a dose of radiation equivalent to that of a chest X-ray.

Orbiting telescope canceled

When the National Aeronautics and Space Administration canceled a planned orbiting solar telescope in 1991, Rust decided to try to tie a telescope to a balloon and send it 23 miles up, short of outer space, but above 99 percent of Earth's blurring atmosphere.

Rust decided to launch his telescope in Antarctica, a good place to launch a solar telescope despite the harsh climate and remote location, because in the austral summer, which is now, the sun shines 24 hours a day.

Rust talked the Air Force into lending him a $12 million telescope. Then the APL scientists built the floating observatory.

With its huge mirror, Flare Genesis is designed to show features on the sun's surface as small as 100 miles across. Rust hopes it will produce images of the sun's surface with 50 times the resolution of other solar telescopes.

When Rust first launched Flare Genesis here in January 1996, a critical antenna fell off and all of its thousands of images of the sun were blurred. When the telescope floated wide of the pole and threatened to land in the stormy Southern Ocean, the APL team triggered the explosives used to separate it from the balloon.

Flare Genesis parachuted onto the ice along the Adelie Coast, about 500 miles from its launch site. For five months, the telescope lay in darkness, exposed to punishing low temperatures and occasionally blasted by hurricane-force winds.

By December 1996, APL engineer Harry Eaton, 36, of Columbia had joined a group of French researchers crossing the interior of the continent by tractor caravan on their way to their coastal research station. During their 16-day trip, they found Flare Genesis. Eaton used a pickax to help free it from the ice.

Redesigned and rebuilt in a garage at APL, the telescope was shipped south again last year. But in New Zealand, Flare Genesis' crate was left outside in the rain, Rust said. The telescope's fragile 32-inch mirror was tarnished. Physicist Pietro Bernasconi had to carefully clean it when he arrived in Antarctica.

That wasn't the only problem. In McMurdo, the top blew off a box of Flare Genesis' electronic equipment, and it filled up with snow. (The equipment didn't appear to be damaged.) Bernasconi and Eaton spent days in an unheated shed, tapping at computers in their parkas and gloves, while they aligned Flare Genesis' optics. Drafts in a heated work space would have distorted their critical measurements.

Around Christmas, the APL team was ready for launch. But strong winds circling the pole at high altitudes and near-calm conditions at the launch site were needed. Without the circumpolar winds, the telescope would drift straight out to sea. Strong, shifting currents near the ground could have sent the telescope tumbling across the ice like a can tied to the bumper of a car.

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