Newspaper: NASA looking into whether upper atmosphere electricity doomed Columbia

SAN FRANCISCO (AP) Federal scientists are investigating whether electricity in the upper atmosphere might have doomed the space shuttle Columbia as it soared over California, the San Francisco Chronicle reported Friday.

Investigators are also reviewing data recorded by a little-known network of instruments that might have detected a faint thunderclap at the same time a purplish bolt of lightning may have struck the shuttle high above Earth, the paper reported.

In a report published last year, researchers at NASA's Kennedy Space Center raised concerns that electromagnetic phenomena or ice crystals from the highest clouds could pose a danger to shuttles on re-entry. Though conditions Saturday were not right for the most dangerous occurrences, some experts caution that much remains unknown about the part of the atmosphere the shuttle was in when it crossed California.

The shuttle was 39 miles above Texas as it disintegrated early Saturday in the searing heat of re-entry, for reasons still unknown. All seven astronauts were killed.

NASA administrators said Thursday that Columbia crash investigators were looking at the photograph of the purplish bolt, captured as a digital image by an amateur astronomer in San Francisco. But Shuttle Program Manager Ron Dittemore told reporters in Houston that NASA isn't sure how important the image may be or whether it's even authentic.

Meanwhile, scientists at a federal lab in Colorado that listens for ghostly electromagnetic phenomena in the upper atmosphere told the Chronicle they were evaluating whether their sensors picked up any strange sounds around the time the shuttle began experiencing problems.

``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.

The lab has a network of electronic ears that can pick up the hiss of space craft re-entering the atmosphere thousands of miles away.

Bedard told the Chronicle that the lab was providing data to NASA but it was too early to draw any conclusions from sounds of the shuttle's re-entry.

(Copyright 2003 by The Associated Press. All Rights Reserved.)