Top investigators of the Columbia space shuttle disaster are analyzing a startling photograph -- snapped by an amateur astronomer from a San Francisco hillside -- that appears to show a purplish electrical bolt striking the craft as it streaked across the California sky.

Wow.

Former shuttle astronaut Tammy Jernigan

The digital image is one of five snapped by the shuttle buff at roughly 5:53 a.m. Saturday as sensors on the doomed orbiter began showing the first indications of trouble. Seven minutes later, the craft broke up in flames over Texas.

The photographer requested that his name not be used and said he would not release the image to the public until NASA experts had time to examine it.

Although there are several possible benign explanations for the image -- such as a barely perceptable jiggle of the camera as it took the time exposure -- NASA's zeal to examine the photo demonstrates the lengths at which the agency is going to tap the resources of ordinary Americans in solving the puzzle.

Late Tuesday, NASA dispatched former shuttle astronaut Tammy Jernigan, now a manager at Lawrence Livermore Laboratories, to the San Francisco home of the astronomer to examine his digital images and to take the camera itself to Mountain View, where it was to be transported by a NASA T-38 jet to Houston this morning.

A Chronicle reporter was present when the astronaut arrived. First seeing the image on a large computer screen, she had one word: "Wow."

Jernigan, who is no longer working for NASA, quizzed the photographer on the aperture of the camera, the direction he faced and the estimated exposure time -- about four to six seconds on the automatic Nikon 880 camera. It was mounted on a tripod, and the shutter was triggered manually.

In the critical shot, a glowing purple rope of light corkscrews down toward the plasma trail, appears to pass behind it, then cuts sharply toward it from below. As it merges with the plasma trail, the streak itself brightens for a distance, then fades.

"It certainly appears very anomalous," said Jernigan. "We sure will be very interested in taking a very hard look at this."

Jernigan flew five shuttle missions herself during the 1990s, including three on Columbia. On her last flight, the pilot of the craft was Rick Husband, who was at the controls when Columbia perished.

"He was one of the finest people I could ever hope to know," said Jernigan.

It was an astounding day for the San Francisco photographer, who said he had not had any success in reaching NASA through its published telephone hot lines.

He ultimately reached investigators through a connection with a relative who attends the same church as former astronaut Jack Lousma, who flew 24 million miles in the Skylab 3 mission in 1973.

Lousma put him in direct touch with Ralph Roe Jr., chief engineer for the shuttle program at Johnson Space Flight Center in Houston.

After a series of telephone conversations Tuesday afternoon, the photographer had a veteran shuttle mission specialist knocking at his door by dinnertime. Within hours, he was left with a receipt, and his camera was on its way to Houston.

©2003 San Francisco Chronicle

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