Steve Quayle News Alerts

June 23, 2003
By Robert Roy Britt, Senior Science Writer

Earth's first line of defense against massive communication failures is expected to go offline this week, raising the very real possibility that should a giant solar flare occur, the disruptions of media broadcasts as well as consumer and military communications dependent on satellites could rise sharply.

These flares are geomagnetic eruptions from the Sun's surface that send giant clouds of electrically charged particles racing towards Earth on the solar winds. While the world's magnetosphere protects us from the flares' radiation, a by-product of this defense -- the particles -- illuminate the skies in a phenomena known as the aurora .

However, there is a negative side to the light show: During such an event everything from television broadcasts to pager services and weather forecasts vital to airlines, even terrestrial power grids, are suddenly more vulnerable to failure.

Normally, the Sun-watching Solar and Heliospheric Observatory (SOHO) spacecraft would give us fair warning of such an event, but the spacecraft's primary antenna has been stuck since last week. Mission officials expect the probe's orbital movement by the end of this week will carry it into a blackout phase.

No solar data or images will be sent home.

SOHO observations are crucial and irreplaceable for scientists who provide advance warning of space storms that can cripple unprepared satellites. During SOHO's blackout periods, space weather forecasting will be set back 20 years, says Joe Kunches, the lead forecaster at NOAA's Space Environment Center.

Kunches and his team of cosmic storm prognosticators will be hamstrung like meteorologists without Doppler.

Media meltdown

Military and media satellite operators will have "less warning time when a solar storm is heading towards us," said Paal Brekke, deputy project scientist for SOHO.

Warnings that are typically two or three days in advance might come with one hour to spare, or not at all. None of this mattered much to the average consumer 20 years ago, when most media and communication was handled over land lines or via broadcast towers.

But today, space is a primary relay point for daily human communication, from pop culture and news to important business messages and phone calls. New media like XM Satellite Radio and DirectTV rely entirely on satellites to reach their customers. Even traditional broadcast stations rely on satellite feeds for portions of their programming.

Advance warning of impending storms allows satellite operators to reduce the risk of damage to some satellites by shutting down electronics. Engineers anticipate problems in an effort to recover damaged satellites before they are lost. Extra staff can be brought in. Agreements are made to shift signals to other satellites.

With or without warning, recent history shows how serious the impact of space weather can be. In 1997, an AT&T Telestar 401 satellite used to broadcast television shows from networks to local affiliates was knocked out during a solar storm.

A more serious breakdown of communications occurred in May 1998 when a space storm disabled PanAmSat's Galaxy IV. Then, though SOHO was flying, researchers had not yet developed the sophisticated prediction abilities they have today.

Among the Galaxy IV casualties: automated teller machines; gas station credit card handling services; 80 percent of all pagers in the United States; news wire service feeds; CNN's airport network; and some airline weather tracking services.

Another space storm in July 2000 put several satellites temporarily out of contact and caused navigation problems in others.

With more craft orbiting Earth than ever before, the risk of losing one in a storm naturally goes up, experts say. Further, modern commercial satellites are typically built in relatively inexpensive fashion and are not as well protected against radiation as government and military satellites.

In 1989, a solar storm tripped a protective switches in Canadian Hydro-Québec power company. The entire province of Québec was without power for nine hours. The problem nearly spread to the United States through an interconnected grid, officials said at the time.

Since then, most power companies have developed programs -- which rely on advance warning of solar storms -- to safeguard their systems.

The Sun's effects are broader still.

In studying the Canadian failure, officials at Hydro-Québec later said solar storms can also corrode oil and gas pipelines and can cause railway crossing signals to self-activate. One recent study showed that even cell phones suffer when the Sun acts up, with calls being mysteriously dropped because radio waves associated with the solar bursts hit cell phone towers.

Sign of aging

SOHO's primary link to Earth, called a high-gain antenna, has been giving engineers fits for more than two weeks. The antenna's motor drive is now mostly stuck. If it can't be fixed, transmission blackout periods will occur for about two-and-a-half weeks every three months.

Officials at the European Space Agency (ESA), which built the spacecraft, Friday called the glitch the "first sign of aging" for the probe.

An earlier wrinkle appeared in 1998, when the billion dollar observatory appeared lost after a navigation problem. For a time, NASA and ESA officials contemplated a replacement spacecraft. SOHO was restored to full operation after about two months, however.

No other satellite or group of satellites can fill the periodic SOHO data voids, experts say, which points out what could be seen as a lack of foresight in the overall space program, because SOHO was never designed to last this long.

The mission, one of cooperation between ESA and NASA, launched in 1995 and was initially planned to last two years. After initial successes, SOHO was given a new lease on life -- meaning more money to pay the ground crew -- so it could observe a peak in solar activity during 2001 and 2002. While mission extensions are common practice when things go well, no spacecraft lives forever.

Fortunately for satellite operators, solar activity is ramping down. A fairly well understood 11-year cycle will reach a low point in about three or four years. But significant flares can still occur at any time, solar physicists say.

Risky options

Late last week, SOHO operators were able to move the antenna slightly, but the hoped-for free movement remained elusive. The antenna was shifted into a "sweet spot," Brekke said, which means interrupted service will be limited to about 19 days every three months, instead of the two-months-in-three that would have been the case.

The first blackout period will begin before June 29 unless full range of motion is attained. After the 19-day blackout, SOHO's orbital position will allow transmissions to resume if operators flip the spacecraft upside down, a feat that will point the antenna toward Earth. That procedure is not considered difficult.

Meanwhile, officials at NASA and in Europe are considering other risky options that might reduce the blackout periods further, Brekke told SPACE.com. One idea was to actually change the spacecraft's orbit, but there is not enough fuel onboard to do that effectively.

"The questions will be if we will stay in this mode the rest of the mission or try to improve it," Brekke said. "There are ways to do this but they may involve risk of ending up in a worse situation than we have."

http://www.space.com/businesstechnology/technology/soho_impact_030623.html