November 3, 1998. Copyright 1998. Graphic News. All rights reserved.

SHOOTING STARS COULD SILENCE CELL PHONES

LONDON, November 3, Graphic News: WHEN a computer failure on board PanAmSatÕs Galaxy 4 satellite sent it into an uncontrolled spin in May, the breakdown had a massive ripple effect, highlighting our dependence on the satellites that orbit the Earth.
Galaxy 4 was responsible for controlling most pagers in America. Millions of people found themselves cut off from contact with offices, homes and hospitals. Switchboards at answering services across the United States were swamped by people calling in to check if they had messages.
Satellites are vital to provide services for television, cell phones, credit card processing, computer networks and global positioning systems as well as the ubiquitous pager.
Recent advances in technology have made spacecraft extraordinarily reliable but even so, radiation, space dust and debris from old launches remain serious hazards for the fast-growing satellite population.
ÔEven though a lot of these objects are small, theyÕre moving at about 70 kilometres per second, which is much faster than anything we can reproduce on earth to study,Õ said David Lynch, a research scientist at Aerospace Corp in El Segundo, California.
At those speeds, collisions with even small particles can result in plasma discharges that can upset operation of flight computers and other components, Lynch said.
The pager problem offers a prelude to what may be a much broader problem this month, when the Leonids meteor shower take the atmosphere by storm.
The Leonids, which are made up of debris spread across the orbit of comet 55/P Tempel-Tuttle, cross paths with Earth every year producing a visible shower of meteoroids. But roughly every 33 years, when Tempel-Tuttle passes particularly close to the sun, the Leonid meteor shower becomes a deluge.
When the shower was last seen in 1966, it generated hundreds of meteors a minute at its peak. Most showers produce only a couple of dozen or so each hour at their zenith.
The Leonids will last from November 14-21, peaking in intensity on the 17th, Lynch said.
Satellites will be in jeopardy from being struck by the minute pieces of dust from the Leonids, travelling at almost four times the speed of typical meteors. Their sensitive electronics could be knocked out by electrical charges generated by the storm.
While there is no way to dodge the downpour satellite operators may choose to point sensitive instruments away from incoming particles or completely power down some systems while the storm passes.
Does that mean that for one day, a digital silence will descend over cell phones, pagers, navigation systems and television? No one knows for sure, since this will be the first time the full-force Leonids strike the 500 or so communications satellites clustered around the Earth.
/ENDS

Sources: Reuters, Cambridge Atlas of Astronomy, spacer.com