Talking by meteor.

Talking by meteor

Shooting stars are good for more than wishing upon, as radio operators know. Since the 1950s, meteors have been put to work as reflectors for adio signals. Now, they may begin working harder than ever -- carrying not only data but also the human voice. In July, engineers from GTE Government Systems in Waltham, Mass., became the first to send a spoken message via meteor trail. The words traveled 418 miles from Westborough, Mass., to Winchester, Va.

The technique can be used during times when naturally occurring ionospheric disturbances interfere with communication by satellite or shortwave radio, according to John R. Herman, the engineer in charge of the recent GTE tests. It also is expected to interest the U.S. military, the GTE subsidiary's primary customer, because it provides a way to communicate during nuclear war -- when communication satellites could be wiped out.

The process is called "meteor burst" communication because it bounces a radio signal off the ionized trail of a meteor, about 60 to 75 miles above ground, in order to send the signal past the horizon. Meteor trails are a reliable way to reflect signals because meteorites enter the earth's atmosphere about 3 to 10 times a second. Amateur radio operators have used them since the 1950s, and more recently, meteorologists have used them as an inexpensive way to send weather data from remote rural areas.

But before meteors could be used to transmit voice, GTE scientists had to write the computer software that enables them to compress a digitized voice signal enough to bounce an entire message off one meteor trail. Each trail lasts from a few hundred milliseconds to a couple of seconds, Herman says.

During the first trials of the system in July, the voice sounded more "computerized" than a telephone voice, Herman says, because of the way the words were digitized and then translated at the receiving end. "It sounded a little better than the computer voice in the movies that speaks in a monotone," Herman says. Improvements in the software should make the voice sound more natural, he says.

Eventually, the GTE scientists expect to be able to send voice signals more than 1,000 miles, Herman says.