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The Day the Pagers Died
Let me leap out of the frying pan into the fire;
or, out of God’s blessing into the warm sun.
Miguel de Cervantes, Don Quixote
On May 19, 1998, modern, high-tech society was zapped back into the phone age. Shortly after 6 p.m. on the East Coast of the United States—while evening commuters were tuning their radios to National Public Radio’s (NPR) “All Things Considered,” while police, rescue, and fire crews were easing into the second shift, while hospitals and obstetricians’ offices were paging their doctors for emergency surgeries and unexpected deliveries—a satellite died. Within moments, NPR and CBS News were scrambling to fill dead air; within hours, thousands of doctors, detectives, and drug dealers were discovering that they had been out of touch all night. By the next morning, newspapers and morning talk shows were buzzing about the day the pagers died.
For reasons that the owners of the Galaxy IV communications satellite could not explain, the $200 million messenger for nearly 90 percent of North America’s pagers and several major broadcast networks had been reduced to space junk. Without a satellite to relay radio signals from dish to dish, paging companies could not deliver messages to their customers. Radio and television stations could not deliver their signals to their affiliates. Millions of North Americans were suddenly forced to live without some of their most prized gadgets. Never before had so many people paid attention to the life and death of a satellite floating 22,000 miles (35,000 kilometers) overhead.
A pair of unrelated incidents, as the PanAmSat Corporation would announce months later, had destroyed the crucial computer processors that kept the satellite pointing at Earth. One computer failed due to the growth of crystals in its circuits. The other failed due to a “random event” that the company could not explain. And since the satellite could not be plucked out of space and examined, no one would ever really know. So without a means to point and orient itself, the satellite went into a spin, lost its way, and became a spare part drifting in space.
To the scientists who study the space around Earth—also known as geospace—the failure of Galaxy IV was no random event. Gathering evidence from half a dozen government research satellites, space scientists proposed their own cause of death for Galaxy IV. In the weeks leading up to the failure of the pager satellite, a series of explosions on the Sun severely disturbed the space around Earth. The barrage left the uppermost reaches of Earth’s atmosphere teeming with “killer” electrons—the kind that murder satellites.
From April 27 to May 6, 1998, the face of the Sun lit up with the solar system’s most common sort of fireworks display. According to Barbara Thompson, a space weather researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the Sun spat
super-hot gas and radiation into space more than 90 times in the two-week span, much of it directed at Earth. And in the days following those solar eruptions, the space around Earth was buffeted by a series of intense space weather storms.
Hardly a static, benevolent body, the Sun constantly seethes with activity, producing the cosmic equivalent of hurricanes and tornadoes. The most famous of these weather events is the solar flare, which scientists and ham radio operators have long blamed for radio disturbances. These bright flashes on the face of the Sun are explosions that release the force of 10 million volcanic eruptions in a matter of minutes. Provoked by the buildup of magnetic energy in the Sun’s atmosphere, flares spew radiation—including radio waves and X rays—and propel some superheated particles across space.
More important from the vantage of Earth, Thompson notes, is the coronal mass ejection (CME), the solar equivalent of a hurricane. Once a graduate student who focused on the physics of Earth’s magnetic field (the magnetosphere), Thompson now looks upwind from our planet, trying to understand how and when CMEs might impact Earth. A CME, she explains, is the eruption of a huge bubble of plasma from the Sun’s outer atmosphere (the corona). CMEs are the principal way that the Sun ejects material and energy into the solar system, and they are the largest structures that erupt from the Sun.
Most CMEs travel at 1 million miles per hour, but the fastest bursts can reach a speed of 5 million miles per hour. But it’s not the speed that kills. A typical CME carries more than 10 billion tons of hot, electrically charged gas into the solar system, a mass equal to that of 100,000 battleships. And the amount of energy trapped in just one of these bubbles is greater than the energy of 1 billion megatons of TNT. Having observed CMEs since 1996 through the telescopes on the Solar and Heliospheric Observatory (SOHO) satellite, Thompson and her colleagues know that these bubbles of solar plasma can pack a punch comparable to that of 100,000 hurricanes.
Just hours after blowing into space, a CME cloud can grow as wide as 30 million miles across, 35 times the diameter of the Sun itself. As it speeds away from the Sun, the CME drives like a plow into the slower, steady solar wind of electrically charged particles, piling the wind in front of it like snow on the blade of the plow. This plow-like effect creates shock waves that accelerate some atomic particles drifting in space to dangerously high energies. Right behind that potent shock, the CME cloud flies through the solar system bombarding planets, asteroids, and other objects with radiation and plasma. If a CME travels on a path that intersects the Earth’s orbit around the Sun, the results can be spectacular and sometimes hazardous.
Conditions were right for such hazards in the spring of 1998. Around April 27, a roiling, turbulent region (officially named active region 8210) popped up near the equator of the Sun, complementing two other active regions on the visible edges of the Sun (see Figure 3). In the next two weeks, instruments on the U.S. Geostationary Operational Environment Satellites (known as GOES, these spacecraft capture the satellite weather images shown on TV) detected 86 flares exploding from the side of the Sun facing Earth. Thompson observed that nearly three-quarters of the flares originated in that one active region—and eight CMEs were spit out of that same hot spot.
But all of the fireworks might have been just a pretty spectacle had they shot off from a different location. In early May, Thompson noted: “Active region 8210 was magnetically well connected to Earth.” As the Sun spews solar wind and its various ejections into space, the material tends to fly off in spirals that are curved by the rotation of the Sun. Earth was sitting at the far end of the spiral (a magnetic field line) that began at 8210, putting it on a celestial beeline from the Sun.
“What was unusual in May was that the active region on the Sun was directly facing the Earth when it let off a bunch of CMEs,” says Thompson, whose past work with space physics has helped her bridge the gap between researchers who focus on only the Sun or on only Earth’s magnetosphere. “There were a lot of energetic
FIGURE 3. The Sun fired dozens of flares and coronal mass ejections into space in April and May 1998, sending a warning shot that solar maximum was on the way. This SOHO image of the Sun in extreme ultraviolet light depicts the flare of May 2, the most potent of the storm. Courtesy of SOHO/European Space Agency and NASA.
CMEs coming from the same region. We see a lot of these kinds of events as magnetic flux emerges on the Sun and forms complex regions during solar maximum.”
One of the first victims of active region 8210 was the Large-angle Spectrometric Coronagraph instrument on SOHO. The camera was flooded with radiation—in the form of protons accelerated by the solar snowplow—several times over a two-week span.
The spacecraft’s image-processing computers slowed to a crawl because there was just too much to see on the Sun. It would take several hours to get them working again.
Downwind from SOHO, NASA’s Wind spacecraft recorded solar wind blowing faster than at any time since the spacecraft had been launched in 1994. Between May 1 and May 19, Wind recorded four separate solar wind streams exceeding 1.3 million miles per hour (600 kilometers per second). On May 4 the solar wind speed peaked at nearly 2 million mph (850 km/s).
On May 4 all of the indexes that measure magnetic and electrical activity in the space around Earth went wild. The auroral electrojet index, which measures the strength of the magnetic disturbances produced by currents in the ionosphere (associated with auroras), reached peak values of more than 2,000 nanoTesla. In the first six hours of the day about 4,600 gigawatt-hours of electrical energy were dumped into the upper atmosphere—more than the total electrical energy produced by all U.S. power stations combined during the same six hours. Another 3,000 gigawatt-hours were dissipated in space to create a huge “ring current” around the Earth. These disturbances had visible effects. On May 4 space weather brought auroras to Boston, London, and Chicago and forced electric companies to reconfigure their power grids in New England.
As detected by several science satellites, the leading edge of Earth’s magnetic field (magnetosphere) was pushed down to 15,300 miles; it normally stretches about 45,000 miles from Earth toward the Sun. Some geosynchronous satellites—which orbit the Earth at 22,300 miles altitude—well inside the magnetosphere and protected from most of the harshest elements of Sun and space—were periodically left twisting in the solar wind. The satellites didn’t move; their whole neighborhood in space moved away for a while.
On the ground in frigid Halley Bay, Antarctica, the storms from the Sun produced their own intrigue. “The aurora australis was
flickering all over the sky,” says Matthew Paley of the British Antarctic Survey, a scientist and aurora watcher. “I could read the label on the back of my gloves by aurora light.”
“We usually get 10 to 20 nights of good aurora in a typical winter, plus frequent steady arcs over the southern horizon,” Paley notes, arcs that are miles away, that result from moderate storms. “The first time people see one of these steady arcs it is an automatic waste of a roll of film.” Such distant arcs are almost boring to the Antarctic veterans, who know that the dancing curtains will eventually appear straight overhead during an intense space weather storm. “The significant auroras are when the arc expands, brightens, and breaks up into complicated waves with bright rays climbing up into the sky,” he added. “These auroras can move over the entire sky and back again in a few seconds, with flickering and bright blobs moving from horizon to horizon.”
More commonly known as the northern and southern lights— the aurora borealis and aurora australis, respectively—these light shows are relatively benign and beautiful signs of Earth’s electric relationship to the Sun. Named for the Roman goddess of dawn, these dancing ribbons and rays of light appear most often in skies above the northern and southernmost parts of the world—Canada, Alaska, Scandinavia, New Zealand—between 65 and 75 degrees of magnetic latitude (from most of Antarctica, that means you have to look north). Auroras are provoked by energy from the Sun and fueled by particles trapped in Earth’s magnetosphere. Like sunspots, they are the space equivalent of the canary in the mineshaft, warning of unseen trouble in the regions around Earth. When the Sun and the space around Earth are really active, auroras have been observed to appear as close to the equator as Singapore.
Auroras are formed by a process that is similar to the way fluorescent lights and televisions work. Some of the currents that flow through the magnetosphere can flow down along the Earth’s magnetic field to form two ovals of current centered on the north and south magnetic poles. If the currents are large enough—such as when they are pumped up by a CME—they cause electric fields to be set up along the magnetic field. The electric fields in turn
accelerate particles, which plunge into the upper atmosphere (an electrified region known as the ionosphere) where they collide with oxygen and nitrogen molecules and atoms. These collisions— which usually occur between 60 and 200 miles above ground— cause the oxygen and nitrogen to become excited and emit light.
The result is a dazzling dance of green, blue, white, and red light caused by the different elements in the atmosphere. Auroras can appear as colorful, wispy curtains of light ruffling in the night sky or sometimes as diffuse, flickering bands. Sometimes they make rays and arcs. In any form, they tell us that something electric is happening in the space around Earth.
“We have a system of wake-up calls where the night watchman wakes the keener people up whenever there is a good aurora,” Paley says. “We generally grab cameras, put on loads of clothes, and go outside to lie on our backs in the snow, which by popular consent is the best position to truly appreciate the spectacle. After 10 to 20 minutes of lying in the snow at 35 degrees below zero, it just gets too cold and people start going inside to defrost before coming out again until they get too cold, tired, or the aurora fizzles out.”
May 4, 1998, was one of those nights when the watchman called. Paley’s journal from that night includes more than eight hours of aurora observations. “The May 4 event looked especially impressive because the arcs were exceptionally bright, numerous, and changeable,” he noted. “The sky also was lit by a diffuse background aurora. When the main arcs surged to a peak in brightness, small details such as the writing on my gloves and my footprints in the snow were clearly visible in the green glow. It is quite common to be able to see silhouettes of people and snowmobiles. But to be able to see clearly—as if by bright moonlight— is really unusual.”
The aurora australis that Paley witnessed that night coincided with one of the larger natural changes of the Earth’s magnetic field ever recorded from Antarctica. The flow of electric currents in the ionosphere decreased and offset the strength of Earth’s magnetic field (as detected on Earth’s surface) by more than 10 percent. From May 2 to 6, high-frequency radio communications were
impossible in the Antarctic because of all of the mayhem in the ionosphere. But at least they had auroral light to read by.
As Dan Baker puts it, blowing a CME across the bow of Earth’s magnetosphere is like exploding a nuclear weapon in space. More specifically, it’s like exploding a bomb in the Van Allen radiation belts, the vast rings of electrically charged particles that swirl in the space near Earth.
For more than 25 years, Baker has been interested in the energy and atoms trapped in the space around Earth. From the radiation belts to the ionosphere to the distant tail of Earth’s magnetosphere, a certain amount of high-energy particles are always suspended above our atmosphere. As an investigator for NASA’s Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) and for the International Solar-Terrestrial Physics program—and as a product of the University of Iowa, where Space Age pioneer James Van Allen held court—Baker has come to know much about the radiation belts.
Discovered in 1958 by Van Allen, the radiation belts are a pair of doughnut-shaped rings of very energetic particles and hot ionized gas (plasma) trapped in the external magnetic field of Earth. Magnetic fields exert forces on electrically charged objects as they move. For charged particles (protons and electrons) that approach near-Earth space, the magnetic force is much stronger than the force of gravity. So when particles arrive from the Sun, Earth’s magnetism takes control of their motion. Earth’s magnetic field is very much like the magnetic field of a bar magnet, where the field comes out of one pole and goes into the other. After charged particles arrive from the Sun and get caught up in Earth’s magnetic field, they spiral along these lines of magnetic force, bouncing from north to south and back again. At the same time, the magnetic field forces the particles to drift roughly in a circle around the Earth (protons drift to the west, electrons to the east). And so the rapidly moving particles are effectively trapped in doughnut-
shaped regions around the Earth, creating the belts of radiation centered around the magnetic equator of the planet.
According to Van Allen, the outer radiation belt stretches from roughly 7,000 to 40,000 miles above Earth; the inner belt lies lower in Earth’s space, inside the outer belt, between 300 and 7,000 miles above Earth’s surface. In the higher latitudes of Earth, near the Arctic and Antarctic Circles, the belts connect to the uppermost portion of the atmosphere (the ionosphere), where they dump those particles that stray too far down the magnetic field lines.
Since the radiation in the belts poses a potential threat to astronauts and to sensitive electronics, engineers have tried to design satellites and human space missions that could overcome the hazards of working in space. Lacking consistent real-time information about what was happening in the belts, they built models and made predictions of “average” intensity. Yet scientists and engineers have known for decades that while the inner belt is relatively stable, the outer belt can vary on relatively short time scales— so conditions are rarely “average.” The best solution was to build “hardened” satellites and spacecraft that could endure a steady dose of radiation (an expensive endeavor), or to place spacecraft in orbits that would avoid spending much time in the high-intensity regions of the Van Allen belts. For instance, satellites in geosynchronous orbit, such as Galaxy IV and most of our weather and communications satellites, reside on the outer edge of the outer radiation belt, where conditions are tolerable most of the time. International Space Station Alpha and the space shuttle are both flown well beneath the inner belt, though they occasionally cross the regions where the belts snuggle close to Earth, such as the South Atlantic magnetic anomaly.
In more comprehensive studies since the last peak of the solar cycle in 1989, Dan Baker and colleague Geoff Reeves have found that the intensity of the belts can actually vary by 10, 100, or even 1,000 times in a matter of seconds to minutes. And regions thought to be safe can, on occasion, be deadly to satellites. “The radiation belts are almost never in equilibrium,” says Reeves, a space physicist at Los Alamos National Laboratory who spends much of his
research time examining space radiation. “We don’t really understand the process, but we do know that things are changing constantly.”
“It’s amazing that the system can take the chaotic energy of the solar wind and utilize it so quickly and coherently,” says Baker, head of the Laboratory for Atmospheric and Space Physics at the University of Colorado. “We had thought the radiation belts were a slow, lumbering feature of Earth, but in fact they can turn on a knife’s edge.” No one has offered a sufficient explanation for the dramatic shifts that the belts can make.
On May 4, 1998, the Van Allen belts took one of those sharp turns, and they did not get back on track for six weeks. In the wake of Barbara Thompson’s solar blasts and Matt Paley’s dancing auroras, the relatively harmless atomic particles that are naturally suspended in the belts were suddenly excited to high energies. According to measurements from spacecraft and ground observatories, a magnetic storm was just beginning to wane when a tremendous shock wave from the Sun arrived on May 4. After being hammered by solar shocks and clouds for a week, then punched one more time, the electrons of the outer radiation belt were screaming around the Earth with energies in the millions of electron volts and at velocities approaching the speed of light. It was as if the electrons and ions had been run through a laboratory particle accelerator.
Driven by processes that are still not understood, the energetic electrons overflowed the two usual radiation belts and also became trapped in between. By the end of May 4, data from NASA’s SAMPEX and Polar spacecraft and several Defense Department satellites showed that a new radiation belt had formed around the Earth. The new belt would last until mid-June.
“We may not be living on the Moon, but society is expanding into space,” says Geoff Reeves, who is developing what he calls “weather maps” of the radiation belts. “Your wireless phone may
be routed through a satellite that has to operate in the radiation belts. The Earth’s radiation belts are in turn connected to things that happen on the Sun.”
“We are going to work in space, to borrow an old space shuttle slogan,” says Reeves. “And much of that work happens on the fringes of the radiation belts.” Knowing something about how the radiation belts behave, and knowing how wild they were in May 1998, Baker and Reeves and other colleagues believe they can make a compelling case that Mother Nature—not some mechanical or engineering error—probably crippled the world’s pager network. They point to a lengthy list of timely coincidences—Baker sees it as circumstantial evidence—to suggest that the cause of Galaxy IV was something less than mysterious and “random.”
While the Sun was raging in April and the radiation belts were tightening in May, one major science satellite failed (Germany’s Equator-S) and several others suffered blackouts and operational problems (NASA’s Polar and Japan’s GMS satellites). News accounts from trade newspapers indicate that Motorola lost four of its Iridium satellites in the second quarter of 1998 (April to June), before they were even put online, and the company could not determine a cause for two of the losses. Galaxy IV failed in the midst of all this activity. And according to one dean of the space physics community, Chris Russell of the University of California at Los Angeles, “the guilt by association is really strong.”
Getting subatomic particles to take out minivan-sized satellites is complicated but not uncommon when the Sun is active, Baker notes. The process is quite similar to shocking or sparking a friend on Earth. Like the 10-year-old dragging his feet on a carpet, a satellite flying through electron-filled space collects electric charge on its surfaces. That charge can build up to a point where it is released quickly as a damaging spark. If sensitive electronic parts or cables are exposed, the shock can upset the spacecraft. Well aware of this problem, engineers design spacecraft with devices or orbit maneuvers that reduce the amount of charge on the surface and keep it from affecting the parts inside.
High-energy electrons, like those swirling in the radiation belts in May 1998, can cause more insidious problems. Baker and colleagues call the process deep dielectric charging. Dielectric materials—insulators that prevent the flow of direct electrical current—cover many of the wires and electronics inside satellites. As satellites drift through space, the ever-present low-energy electrons tend to accumulate and stick to the outer surfaces, never reaching the sensitive electronics inside. High-energy electrons—a reporter once dubbed them “killer electrons” and scientists kept the name—can penetrate the shell of the spacecraft and lodge themselves in the dielectric insulation around the electronic nerve centers (computer chips, coaxial cables, etc.). Under normal circumstances, very few high-energy electrons lodge in the dielectric materials, and most naturally leak away over time. But when high-energy electrons overwhelm a spacecraft, the sparks can fly, frying million-dollar equipment.
“Dielectric charging can cause, or at least exacerbate, problems with spacecraft electronics,” asserts Baker, who is accused by some industry colleagues of howling at the space weather Moon. He has closely studied several spacecraft failures, such as the demise of Canada’s Anik E1 and E2 satellites in 1994, and has found strong evidence that long periods of exposure to concentrated radiation can wreak havoc on satellite hardware. Even hardened U.S. Air Force satellites have suffered from long-term, high-energy particle baths. “No matter if there is some other flaw in the satellite,” Baker notes, “charging can push a touchy system over the edge.”
In an article published in the scientific newspaper Eos in October 1998,1 Baker, Reeves, and Joe Allen (former head of the solar-terrestrial physics division of the National Geophysical Data Center, part of the National Oceanic and Atmospheric Administration) dared to suggest what most space weather researchers usually only claim in private. In print for all of their colleagues, they made the case that Galaxy IV was likely overwhelmed by more killer electrons than it was designed to handle. Anticipating critics who would claim that there was no single day when the
amount of killer electrons reached a precipitous peak, the scientists observed that the May event was one of the longest and most extreme cases of interaction between Sun and Earth in the 1990s. The amount of high-energy particles in the magnetosphere was well beyond the norm for more than three weeks. The result, the scientists asserted, was a slow, wasting death for Galaxy IV.
Geoff Reeves explained it this way. “If you punch some holes in a coffee can and leave it out in a slow rain or drizzle, the can will never get full,” he says. “But leave it out in a downpour and very soon the can will be overflowing.” He believes Galaxy IV was probably drowned in the steady downpour of killer electrons.
Without access to proprietary data from PanAmSat or Hughes Space and Communications (which built Galaxy IV and 40 other satellites of the same class), space scientists and most of the public will never know for sure what killed Galaxy IV, a satellite that was expected to last another five to 10 years. But after speaking with colleagues in the satellite industry, many in the science community remained confident that the dielectric-charging hypothesis was sound. In fact, the head of the National Oceanic and Atmospheric Administration, James Baker, made a point of highlighting the failure of Galaxy IV during a November 1999 press conference even as colleagues from his industry sat next to him.
“None of these things can be proven definitively,” says Gordon Rostoker, a colleague of Baker and Reeves who runs a network of magnetic observatories in northern Canada. “After all, the satellite is 33,000 kilometers up there, and you can’t go out and check the circuits. But when you have all of these birds having all of these problems, to say it’s just engineering is silly.”
As private companies, PanAmSat and Hughes do not have to release reports from their internal investigations. And as a player in the multibillion-dollar satellite communications industry, Hughes has an interest in attributing the failure to poor engineering and random events. Engineering failures can be covered by insurance policies and prevented in future satellite designs. Acts of God or the Sun are not always insurable or preventable.
In the Eos article, Baker, Reeves, and colleagues noted that, “whether or not the incident on May 19 was caused by space weather, it nonetheless shows the vulnerability of society to individual spacecraft loss. The vast number of users affected by the loss of just one spacecraft shows how dependent society is on space technology and how fragile communications systems can be.” About 80 to 90 percent of all North American pagers were affected by the failure of Galaxy IV, according to a spokesman for PageNet, one of the nation’s largest paging companies. Between 45 million and 49 million people use pagers, and at least 40 million of them lost that privilege on May 19. Doctors and nurses could not be reached for emergency calls. Real estate agents and corporate executives missed important messages. Drug pushers missed a few deals. It was the first major outage in 35 years for the paging industry.
The effects of Galaxy IV’s early demise spread well beyond the pager networks. NPR depended wholly on the satellite to distribute its popular “All Things Considered” news program to stations across the country. At the time of the outage, the two-hour show was in the midst of its second broadcast feed of the afternoon, with one more to go before the afternoon drive time would be over. When Galaxy IV shut down, NPR stations endured several minutes of dead silence before switching to alternate satellites, phone lines, and the Internet to get the program out to local stations.
CBS radio and television, the Chinese Television Network, and CNN’s Airport Network all lost signals routed through Galaxy IV. Reuters news service lost some of the reports it was sending through the communications satellite. And the satellite carried important weather information to numerous industries and agencies. Some radar signals and imagery for aircraft, agriculture, commodities traders, farmers, and emergency managers were temporarily wiped out for large portions of the United States. At airports, many airlines (including American, United, USAir,
Continental, Delta, Federal Express) lost some of the weather-tracking information they use to plan routes and forecast arrival times. Some air traffic control data were knocked out, as well, although the Federal Aviation Administration assured everyone that the data were not critical.
How could such a large communications network be brought down by one satellite? Stationed in prime space real estate at longitude 99 degrees W (above Kansas), Galaxy IV was in the perfect position to reach the entire United States with almost no interference from mountains, buildings, or even the horizon. And because of its signal capacity, the satellite was able to link up many clients, particularly pager networks because they use so little bandwidth. PanAmSat had pitched Galaxy IV as the ultimate satellite for paging services, and most companies bought the idea—so many that an entire industry collapsed, albeit briefly.
In the days and weeks after the Galaxy IV failure, PanAmSat initiated a contingency plan by moving the dead satellite to a higher orbit and moving another of its satellites, Galaxy VI, to Galaxy IV’s old neighborhood. Within days, most of PanAmSat’s customers were back online.
Meanwhile, engineers from PanAmSat and Hughes Space and Communications conducted an “extensive analysis of the cause of the spacecraft control processor failures.” In the 12 years since Hughes had begun building and flying the HS 601—the model of satellite that included Galaxy IV—there had never been an “operational failure.” In fact, since 1963 no other Hughes-built satellite of any kind had failed.
Three months after the May space weather barrage, officials from the two companies announced that the demise of the communications satellite was caused by two separate problems. Laboratory tests of spacecraft components suggested that Galaxy IV’s primary control system was felled by the formation of crystals on the system’s tin-plated relay switches. Barely the width of a human hair, the “tin whiskers” had caused catastrophic electrical shorts in Galaxy IV’s circuits. Identical shorts in tin-plated relays would later disrupt PanAmSat’s Galaxy VII satellite in June 1998 and one
of Hughes’s DirecTV satellites in July 1998, though in each case the satellites successfully switched to backup systems.
In May 1998, Galaxy IV had no backup ready to take over when the primary system failed. Analysis of components and data from an identical test satellite in the lab was inconclusive. So in an August 1998 announcement and in financial reports filed by PanAmSat, the company declared the failure of the backup to be a “different, isolated incident” from the tin-plated switch problem. Company officials called it a “one-time, random event.” Some satellite engineers privately asserted that the second failure was also a “tin-whiskers” problem. But as Joe Allen points out, the failure need not be pinned solely to engineering or the environment. “If the solder joints and sockets of circuit board components develop these extended whiskers under the temperature and pressure conditions in orbit,” Allen notes, “and they create a narrow gap between an active circuit and another conductor, across which a spark can jump with greater facility than would otherwise happen—then wouldn’t you expect to see both tin whiskers and disturbed space environment conditions happening at the same time? This is likely a case where the environment exacerbated an engineering problem. Usually the satellite builders like to emphasize engineering, and I emphasize the space environment, and we’re both right to some extent.”
Though PanAmSat lost tens of millions of dollars in business and in hardware costs, the satellite itself was insured for $165 million, lessening the blow somewhat. But the damage does not necessarily end with the replacement of the satellite or the redirection of business. Investors grow wary of companies with satellites that are perceived to be vulnerable—even if the failures are rare. Competitors remind potential customers that “our satellites don’t fail,” even if they just happen to be lucky to have escaped the latest storm.2
During the past decade, the failure rate of satellites has been about 1 percent, according to William Kennard, former chairman of the Federal Communications Commission. “This type of disruption in satellite service is extremely rare.” But Kennard’s assess-
ment fails to take into account that most of the current commercial satellites were launched during the relatively mild middle of the 11-year solar cycle.
With solar activity reaching a crescendo in the solar maximum period of 2000 to 2002, satellites are under more stress than they ever endured during the comparatively benign solar minimum of the mid-1990s. And there will soon be a lot more satellites to worry about, with 1,200 expected to be in orbit by the middle of the first decade of the twenty-first century (compared with 650 at the end of the twentieth century). In an expanding and competitive satellite industry, many companies are launching “better-faster-cheaper” satellites—and a key cost-saving measure is to scrimp on heavy and expensive shielding that protects satellites from the natural environment.
One would think that events like the May 1998 storm would convince satellite operators and their customers to spend more on their satellites or to prepare for more frequent losses. The lesson that the paging and telecommunications companies learned is that more backups are needed. The broadcast television industry, for example, is known to spread out its wireless connections and have alternates lined up if a satellite is knocked out. But many newcomers to the world of satellites—the cable and satellite TV companies, the upstart phone services, the teleconferencing networks, the financial markets—could be caught without an alternative when their satellite fails.
“It seems inadvisable to have such complex, societally significant systems susceptible to single spacecraft failures,” notes Dan Baker. “With spacecraft operators working much closer to the margins, and with the recent record of space environmental disturbances, I believe many more catastrophic failures may occur.”
In his testimony to a Senate panel in May 1998, computer scientist Peter Neumann of SRI International warned lawmakers about the dangers of too many eggs in one satellite basket. “The failure of Galaxy IV is just another example of the flaky infrastructure we’re dealing with,” Neumann told the Senate Committee on Governmental Affairs. “The companies that are smart have antici-
pated things like this and they have backups. But there are also a lot of naive folks who are dependent on one technology.” He added: “As-yet-undiscovered vulnerabilities may be even greater than those that are known today. Future disasters may involve vulnerabilities that have not yet been conceived, as well as those that are already lurking.”
