BEEPER DEPENDENCE EXPOSED.

Byline: Laurence Zuckerman The New York Times

Tens of millions of Americans became keenly aware of their dependence on yet another Space Age technology Wednesday, after a communications satellite orbiting 22,300 miles above the equator went on the blink.

But satellite-industry analysts and executives described the problem as an extremely rare event and said that as more satellites were lofted into space in the next two years, the number of spares would increase.

The mysterious problem that paralyzed PanAmSat's Galaxy IV satellite knocked out the transmission of some television and radio signals, as well as data. But the crippling of much of the nation's pager network created the greatest inconvenience.

Workers around the country who had come to depend on their beepers for everything from emergency calls to the price of soybeans were suddenly in the dark. As in a major electricity blackout or the disruption of telephone service, users suddenly realized how much they had taken technology for granted.

``The paging companies are learning that a lot of people really rely on this stuff,'' said Clayton Mowry, director of the Satellite Industry Association. ``There may be some reconsideration of how these guys use services in terms of having backup capacity.''

The satellite industry sprang from the imagination of writer Arthur C. Clarke in the 1940s and only began growing commercially in the early 1980s. It is now a $51 billion industry that is expanding 14 percent a year, Mowry said.

Paging, which requires only a small amount of bandwidth, or transmission capacity, represents a tiny fraction of the industry's overall sales. Satellite networks connect grocery stores with their warehouses, they allow people to add fuel to their cars with the swipe of a credit card at the pump, they transmit up-to-the minute data to financial traders.

``You don't look at the dish on top of the Piggly Wiggly and the Safeway, but it is there,'' Mowry said.

One reason the failure was so notable was that satellites have been so reliable. There have been many problems launching them in recent years, but once in place they rarely malfunction.

``We're very dependent on it because it is a very efficient infrastructure,'' said Robert Kaimowitz, satellite-industry analyst at C.E. Unterberg, Towbin, a New York investment bank.

Frederick Landman, the chief executive of PanAmSat, said nearly 200 commercial satellites were in orbit and that the failure rate was less than 1 percent. ``It is probably a lot less likely to happen than a backhoe digging up a cable in a trench,'' he said.

Indeed, land-based lines fail far more often, as do underwater cables that carry telephone calls. When they fail, satellites are used as a backup.

Landman said PanAmSat was still not sure what had caused the Galaxy IV to malfunction Tuesday around 6 p.m. The satellite, shaped like a 9-foot cube with a solar panel stretching 100 feet, is still in a stable orbit above the equator, but the system that keeps it pointed at Earth malfunctioned, causing it to spin. A backup system also failed.

Galaxy IV, launched in 1993, was made by Hughes Space and Communications, part of General Motors Corp.'s Hughes Electronics subsidiary, which also owns 81 percent of PanAmSat, the largest domestic satellite operator.

This type of communications satellite costs $200 million to $250 million to make and launch, a process that can take two years. Until recently, spares were rare. But as the industry has advanced, the use of backup satellites is expanding.

DirecTV, another Hughes unit that offers direct broadcast satellite television services to millions of homes, has spare satellites in the same orbit so that if one fails, the company can immediately switch to the backup.

PanAmSat, which has a total of 17 satellites in orbit, had one spare. It said Wednesday that it was moving Galaxy VI to a new orbit to take over for the crippled Galaxy IV, a process that would require six days. It also shifted some customers to a third satellite, Galaxy III R.

Landman said Galaxy IV represented less than 10 percent of PanAmSat's total capacity. Over the next two years, the company plans to launch seven more satellites, increasing its capacity nearly 70 percent and allowing for more backup.

Already, some of Panamsat's customers regularly reserve capacity so they are not dependent on a single satellite. CBS Television was planning to broadcast on Galaxy IV and shifted to a backup when the satellite went down. Home Box Office, the first satellite TV network in the mid-1970s, uses a variety of satellites.

But many businesses, like the paging companies, do not have the resources to keep a satellite idling in reserve. Even if they did, moving to an alternate satellite in a different orbit is a labor-intensive process.