`Storms' in Space May Zap Satellites

Article excerpt

Scientists are forecasting some really bad weather in space this year - a meteor shower and solar flares, either of which could knock out one or more of the 2,565 satellites that today's high-tech society depends upon.

The Hubble Space Telescope, NASA's eyes into the far corners of the universe, also could be affected.

Every November, Earth passes through debris the sun has boiled off from the comet Tempel-Tuttle - a cloud of ultrafine particles called the "Leonid shower" because it appears to be coming from the direction of the constellation Leo. This meteor shower reaches a peak once about every 33 years.

That's this year, on Nov. 17.

The meteor shower, which will last several hours, is currently the subject of memos and meetings in the National Aeronautics and Space Administration, Intelsat, the Air Force and the scientific community.

During a normal year, the shower's peak rate is about 10 to 15 particles per hour. This year, it is expected to be 200 to 5,000 particles an hour.

"It will be the highest number of meteors that the current population of satellites has ever seen," said William Ailor, director of the Center for Orbital and Re-entry Debris Studies at the Aerospace Corp. in El Segundo, Calif. "Back in 1966, we didn't have as many satellites, and we weren't as dependent on them as we are now. That's why it's such a noteworthy event."

A less-intense meteor shower in 1993 knocked out the European Space Agency's Olympus communications satellite.

Another concern of the scientific community is that solar activity is getting more intense.

Solar activity seems to vary in 11-year cycles marked by changes in the number of sunspots. As the spots increase, so does the activity of the sun, with blasts of superhot gases swirling about, sending out pulses of atomic particles, X-rays and other electromagnetic waves. Cycle 22 peaked in July 1989. Cycle 23 will peak in 2000, but the effects of the increase in solar activity already can be seen.

"We're entering a solar maximum period of a couple of years," said Bill Steigerwald, public affairs officer of space science at the Goddard Space Flight Center in Greenbelt.

A solar flare is thought by some to be the culprit behind the PamAmSat Galaxy IV disaster that silenced pagers and National Public Radio broadcasts last month.

Scientists also blamed a solar eruption for the January 1997 failure of AT&T's $200 million Telestar 401 satellite.

Because of the unpredictability of solar flares, it is impossible to prepare for them other than to build stronger satellites, according to David Speich, a scientist with the Space Environment Center in Boulder, Colo.

"Most satellite engineers know how to build satellites to protect against the flares," Mr. Speich said. "They choose materials and designs to mitigate the effects."

Preparations can be made, however, for the meteor shower. For example, NASA will reposition its Hubble Space Telescope.

"We plan to turn the Hubble telescope around so the back end is facing the meteors and the sensitive optics point away from the shower," said Don Savage, public affairs officer for NASA's space science office. …