Cosmic bolt probed in shuttle disaster

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Cosmic bolt probed in shuttle disaster

Scientists poring over 'infrasonic' sound waves

 

 

Federal scientists are looking for evidence that a bolt of electricity in the upper atmosphere might have doomed the space shuttle Columbia as it streaked over California, The Chronicle has learned.

 

Investigators are combing records from a network of ultra-sensitive instruments that might have detected a faint thunderclap in the upper atmosphere at the same time a photograph taken by a San Francisco astronomer appears to show a purplish bolt of lightning striking the shuttle.

 

Should the photo turn out to be an authentic image of an electrical event on Columbia, it would not only change the focus of the crash investigation, but it could open a door on a new realm of science.

 

"We're working hard on the data set. We have an obligation," said Alfred Bedard, a scientist at the federal Environmental Technology Laboratory in Boulder, Colo. He said the lab was providing the data to NASA but that it was too early to draw any conclusions from the sounds of the shuttle re-entry.

 

The lab has been listening to the sounds of ghostly electromagnetic phenomena in the upper atmosphere, dubbed sprites, blue jets and elves. For some time, scientists have speculated on whether these events could endanger airliners or returning spacecraft.

 

A study conducted 10 years ago for NASA found that there is a 1-in-100 chance that a space shuttle could fly through a sprite, although it concluded that the consequences of such an event were unclear. And in 1989, an upper- atmospheric electrical strike "shot down" a high-altitude NASA balloon 129,000 feet over Dallas.

 

NASA officials have said they are looking for a "missing link" to explain the shuttle's breakup that killed seven astronauts Saturday, and they are downplaying the theory that foam insulation falling from the shuttle's extra tank may have contributed to the shuttle's demise.

 

The little-known infrasound project at the Environmental Technology Laboratory operates a network of sophisticated electronic ears that can pick up subaudible thuds of waves crashing on either coast of the United States and the hiss of meteors and spacecraft re-entering the atmosphere thousands of miles away.

 

Sound waves of this nature are called "infrasonic" and are below the range of human hearing but travel unimpeded for extraordinary distances. Arrays of infrasonic sensors in the high Colorado plains east of Boulder recently have been looking for the crackle of the ghostly electromagnetic events in the Earth's upper atmosphere.

 

"We basically detect events at very long ranges," Bedard said. But he stressed that it was too early to draw any conclusions from sounds of the shuttle re-entry. Bedard said the acoustic sensors had previously detected the re-entry of a space shuttle from Northwest Canada to the Kennedy Space Center.

 

 

CELESTIAL THUNDERCLAP

Originally, it was thought that the electrical charges in the thin atmosphere 50 miles above Earth were too dispersed to create infrasound. But Los Alamos National Laboratories physicist Mark Stanley said that, on closer inspection, "we've seen very strong ionization in sprites" indicating that there were enough air molecules ionized to cause heating and an accompanying pulse -- a celestial thunderclap, as it were.

 

NASA administrators confirmed Thursday that the photograph, taken from Bernal Heights in San Francisco by an amateur astronomer, is being evaluated by Columbia crash investigators. However, Shuttle Program Manager Ron Dittemore told reporters at a Houston news briefing that right now NASA is trying only to verify "the validity" of the image.

 

The astronomer, who has asked that his name not be used, has declined to release the digital image to the media. But earlier in the week, he permitted Chronicle reporters to view the image and invited one to his home Tuesday evening, when the camera, and a disk of the image, were turned over to former shuttle astronaut Tammy Jernigan for transit to Houston.

 

The image was also e-mailed Tuesday evening to Ralph Roe Jr., chief engineer for the shuttle program at Johnson Space Flight Center in Houston.

 

Dittemore would not say during the news conference whether NASA has ruled in or ruled out one possible explanation for the photo: that the image could have been caused by jiggling of the camera. It was a Nikon M-880 mounted on a tripod. The automatically timed exposure of four to six seconds was triggered by finger.

 

"We have to validate whether it is real," Dittemore said. "This particular one is no different from the others. . . . It has yet to be determined whether this is important to us or not."

 

 

SEEKING EVIDENCE

NASA officials have stressed the importance of photographic, video or debris evidence from the earliest moments of the shuttle's distress, which sensors indicate began at about 5:53 a.m. above California. That's when sensors in a wheel well blinked out, in the words of NASA investigators, "as if someone cut a wire."

 

That is also roughly the time during which the amateur photographer snapped his image of Columbia as it streaked across the sky north of San Francisco. A precise time may be mapped by matching the photo and the strange electrical signature to the crisp background field of stars.

 

Physicists have long jokingly referred to the lower reaches of the ionosphere -- which fluctuates in height around 40 miles -- as the "ignorosphere," due to the lack of understanding of this mysterious realm of rarefied air and charged electric particles.

 

The family of "transient" electrical effects occupy this part of the sky, including sprites, which leap from the ionosphere to the tops of thunderheads, and blue jets, which leap from thunderhead anvils to the ionosphere.

 

Streamers of static electricity can travel these realms at speeds 100 times that of ground lightning, or 20 million miles an hour.

 

Ten years ago, Walter Lyons, a consultant with FMA Research Inc. in Fort Collins, Colo., conducted a study of sprite danger for NASA. "We concluded that there is about 1 chance in 100 that a shuttle could fly through a sprite. What impact, we didn't know for certain. It didn't appear at this time that the energy would be enough to cause problems."

 

But Lyons conceded that the "ignorosphere" is a mysterious place that has yielded startling surprises. "Since then, with research on electrical streamers, the discovery of blue jets, the doubt has gone up," he said.

 

"There are other things up there that we probably don't know about," Lyons said. "Every time we look in that part of the atmosphere, we find something totally new."

 

 

LACK OF RESEARCH FUNDING

But the field is dominated by a small club of electrophysicists who have seen their money for research dry up. Ironically, an experiment of Israeli astronaut Ilan Ramon, aboard the doomed Columbia, was among the last fully funded work conducted on sprites. Lyons, considered to be one of the leading authorities, said he played a role in the design of the experiment.

 

To date, sprites have required the presence of a significant electrical storm on the ground. As the shuttle passed over Northern California, there were some heavy rain showers in the far north of the state, but none of the wild weather normally associated with sprites.

 

Hearing a description of the purplish, luminous corkscrew in the San Francisco photograph, Lyons said, "This was not a sprite event . . . but maybe it is another electrical phenomenon we don't know about."

 

Whether or not an electrical discharge might be involved in the demise of Columbia, there is precedent for an event like this.

 

Scientists have observed interaction between a blue jet and a meteor. And in December 1999, Los Alamos National Laboratories researcher David Suszcynsky and colleagues, including Lyons, published an account of a meteor that apparently triggered a sprite. Their account is published in the Journal of Geophysical Research.

 

"It was a singular observation that had us all scratching our heads," said Lyons. In the strange world of sprite and elf research, scientists have documented one event in which some sort of high atmospheric event "shot down" a high-altitude balloon over Dallas.

 

On June 5, 1989, before the first sprite was ever photographed, a NASA balloon carrying a heavy pack of instruments suffered "an uncommanded payload release" at 129,000 feet, according to Lyons. It landed in an angry Dallas resident's front yard.

 

Investigators found scorch marks on the debris and considered it one of the first bits of solid evidence that sprites exist. As a result of the accident, NASA no longer flies balloons over thunderstorms.

 

Ironically, the balloon was launched from a NASA facility in Palestine, Texas, one of the towns where debris from the space shuttle Columbia fell Saturday.