Solar Storm Eyed as Satellite Killer

Dr. Sten Odenwald (Raytheon STX, NASA Goddard Space Flight Center)

On January 7, 1997 it seemed to be an ordinary day on the Sun. White light photographs taken at the ordinary. In fact, to the eye and other visible wavelength instruments, the images showed nothing at all. Not so much as a single sunspot.

But X-ray photographs taken by the YOHKOH satellite from earth orbit revealed some serious trouble brewing. High up above the solar surface in the tenuous atmosphere of the Corona, invisible lines of magnetic force, like taught rubber bands, were coming undone. On January 6th, satellite images showed a coronal storm brewing from a small region of the Corona ONLY a few hundred times the size of the Earth.

By Tuesday, January 7th, solar astronomers recognized that a major Coronal Mass Ejection event was in progress, and in a sequence of daily X-ray images, the details of the event played themselves out in a deadly dance of magnetic fields, plasma and electromagnetic radiation.

The dance lasted several days, but by its end, a cloud of plasma was hurled away from the Sun at 1 million miles an hour. It crossed the orbit of Mercury in less than a day. By Wednesday it had passed Venus: An expanding cloud over 30 million miles deep, spanning the space between the orbits of Mercury and Venus. As NASA astronomer Stephen Maran noted about the 20 satellites that had monitored this event, "This is the first time a solar event has been captured from cradle to grave".

Despite the scientific excitement over this storm, it had other repercussions that were far less welcomed. The problem is that, even with detailed information about an incoming solar cloud, short of moving the earth out of the way, there was nothing we could do in the face of this looming calamity. All scientists could do was to sit back and cross their fingers that the Earth's magnetic field would repel most of the cloud like some gigantic security blanket. After all, it had done so for million of years in the past! But today, our daily sphere of activity extends off the surface of the Earth and far into space.

High up above the United States, AT&T's Telstar 401 satellite was busy relaying television programming between many destinations across the continent. Public Broadcasting Stations, ABC News and even the Home Shopping Channel were among its regular paid subscribers for the precious few channels that the satellite could re- broadcast back to our home television sets and to cable channel owners on the ground. Telstar 401 was launched from Cape Canaveral on December 13, 1993 and was the first of a fleet of modern communications satellites developed by Lockheed-Martin, and equipped with many new technologies. It was designed to 12 years, but on Saturday, January 11 AT&T announced that it was having some communications difficulties with the satellite. It's day of reckoning had arrived, as the interplanetary coronal storm cloud, now over 30 million miles wide, slammed into the Earth's magnetosphere. Even the images from the YOHKOH satellite began to deteriorate as the plasma particles and magnetic fields invaded the delicate electronic circuitry, corrupting the images with noise.

In a report by Aviation Week and Space Technology (AWST) magazine ( January 27, 1997, p. 61) the Telstar satellite "...suffered a massive power failure on jan. 11 rendering it completely inoperative. Scientists and investigators believe the anomaly might have been triggered by an isolated but intense magnetic substorm, which in turn was caused by a coronal mass ejection...spewed from the Sun's atmosphere on Jan. 6". Some scientists were not so ready to implicate the solar storm in the damage to the satellite. Robert Hoffman, a NASA scientist, is quoted in AWST as saying that although the satellite was located in an affected area of the magnetosphere, "We have no idea what caused the failure".

Despite a number of attempts at diagnosing and repairing the problem with Telstar 401, on Saturday, January 17 AT&T had given up the effort and announced that they had lost the satellite. A $200 million satellite had been short circuited. A piece of the sun had, apparently, reached out and touched the earth, rendering the satellite useless. The trigger had been pulled by an event on the Sun that, like a hunter in a duck blind, was stealthly hidden from view from earth-bound observers. But perhaps not.

No military satellites were apparently affected by this particular storm, and Hughes Space and Communications which manufactured over 40% of the commercial satellites now in orbit had also not received any reports of any anomalies related to the storm. According to AWST, Lockheed Martin which built the Telstar 401 satellite was investigating whether the failure could have been due to some problem in its design. Three earlier-model satellites were also disabled in 1994 by a solar storm which triggered electrical failures in these satellites: Intelsat K and two Canadian Anik television satellites. Two of them made partial recoveries but the third was lost completely. (AWST January 31, 1994 p. 28).

Although satellite engineers and scientists are cautious to admit blame when hundreds of millions of dollars are at stake and law suits could result from the wrong answers, the immediate repercussions of the Telstar 401 loss were significant. The many paying customers of the satellites's transponder channels had to quickly switch to other satellites where space was available to carry their programming. Some customers did not have contingencies written into their service contracts with AT&T, and were left in complete blackout. Many newspapers stories were filed about this event and its fallout, and on January 30, 1997 even George Will at the Washington Post, who normally covers political stories, wrote Astronomy's Answer an anguished editorial about space calamities that can, and will affect us.