Sunday, August 24, 1997

NASA, NOAA hope to issue warnings of solar storms with a $110 million observatory

By Seth Borenstein / The Orlando Sentinel

CAPE CANAVERAL, Fla. - Every 11 years or so, the sun spews nasty solar flares that foul up satellite transmissions and cause massive blackouts to power systems on Earth.

Those solar storms have come like bolts out of the blue, surprising an unprepared Earth. But NASA and the National Oceanic and Atmospheric Administration hope to issue warnings the next time solar flares peak, in about 2000.

A $110 million observatory called ACE (Advanced Composition Explorer) is expected to provide that warning. It is scheduled to launch Sunday at 10:41 a.m. aboard a Delta II rocket at Cape Canaveral Air Station.

ACE will travel about 1 million miles from Earth and stare at the sun, which will be another 92 million miles away.

"ACE will be the sentinel for particles coming from the sun bombarding Earth," NASA scientist Vernon Jones said.

It won't be much of an advanced warning, just an hour.

But an hour will be enough, said Ron Zwickl, scientist at NOAA's Space Environment Center in Colorado.

In 1989, the last "truly Draconian" solar storm brought down an entire power grid in the Canadian province of Quebec and nearly the rest of the U.S. East Coast, Zwickl said. With one hour lead time, utilities can reduce power on their lines so extra electromagnetic charges from the sun won't overload the system, he said.

The same solar storms have such intense radiation that they could kill astronauts in unprotected spaceships heading to Mars or the moon, Zwickl said. So these ships could have specially designed safe areas with shielding, and ACE would warn astronauts when to head for safety. Earth is shielded from this radiation by the atmosphere.

Being able to issue solar storm warnings is a bonus scientists hope to get from ACE. It's really a science project to study particles ejected from the sun and the interstellar medium, which is the stuff floating around in the galaxy from exploded stars, said Ed Stone, the chief scientist for ACE.

"The sun is the one object where we don't really have a very good idea what it's made of," Stone said.

By examining material expelled by the sun, ACE will find what elements the sun contains and in what proportions, he said.

There's a lot of stuff spewed by the sun to study. In just a few hours during a solar storm, it sends out 100 million tons of materials, creating shock waves in space, Stone said.

The observatory was supposed to cost NASA $141 million to build, but it came in $30 million under budget, officials said. NASA also is paying $51.5 million to launch the observatory on Boeing's Delta II rocket.

NASA was able to save money by using instruments designed for other projects, using more off-the-shelf equipment, and coming up with a new way of fueling the observatory, mission manager Don Margolies said.

Visit the Sentinel on the World Wide Web at http://www.orlandosentinel.com/. On America Online, use keyword: OSO.

Distributed by Knight-Ridder/Tribune Information Services.