NASA identifies ‘critical’ piece of shuttle

Hopes for another significant find were dashed on Monday evening. Early in the day, field investigators reported that they had located one of five ‘‘general purpose computers’’ responsible for flying the shuttle. But it turned out to be another type of wreckage, not a ‘‘GPC.’’ ‘‘I don’t have word yet on what it is,’’ said NASA headquarters spokesman Al Feinberg. The fragment includes about 2 feet of the wing’s leading edge, which is covered by panels of a reinforced carbon material designed to withstand 3,000-degree temperatures. There is also about an 18-inch portion of the wing structure itself.

Kostelnik said there was ‘‘uncertainty among people who recovered it’’ about what part of the wing they were looking at. Investigators are keenly interested in the area near where the wing joined Columbia’s fuselage, because during launch it was struck by a piece of insulating foam that broke off the shuttle’s external fuel tank.

But NASA officials are skeptical that damage during launch led to the loss of Columbia. They say they are uncertain about the quality of the image from the Air Force camera. Investigators have ruled nothing out, and NASA is trying to find whether Columbia may have been hit by a meteorite in the flight, or whether frozen waste water from the shuttle could have caused damage during orbit.

The piece of wing was found southeast of Dallas. Officials had initially said they believed that it had come from the western edge of the debris field. That would have made it even more significant, since pieces farther to the west are more likely to have been shed from the craft first.

A key milestone for the investigation could come on Wednesday, when O’Keefe testifies at Capitol Hill before a joint hearing of the House and Senate committees. The Bush administration may revamp the Columbia investigative board, now composed of current and former government officials. (LATWP)