spacetoday.net: NASA now discounts foam as cause of accident

Posted: Thu, Feb 6, 2003, 8:41 AM ET (1341 GMT)
STS-107 patch (NASA)

NASA investigators said Wednesday they now no longer believe that a chunk of foam insulation could have damaged tiles on the shuttle Columbia to the extent required to explain the accident that destroyed the orbiter. Although officials said earlier in the week that they were working on the assumption that the impact of the insulation on the shuttle's left wing during launch was the root cause of the accident, new studies have changed that opinion. Shuttle program manager Ron Dittemore said that the foam chunk was moving at only half the velocity earlier reported and models that showed that the impact could have caused little damage to the tiles traditionally overestimates the degree of damage in the first place. Dittemore also discounted the possibility that the chunk was mixed with ice, or composed of ice entirely, noting that there was no evidence of ice on the tank during pre-launch inspections, and that the insulation is water-repellant. Tracking camera images of the shuttle released Wednesday also show no evidence of gross damage to the underside of the shuttle's left wing after the foam impact. Investigators have now turned their attention elsewhere, looking for a "missing link" that has escaped detection to date. This has put additional emphasis on searches for debris west of the main impact field in Texas and Louisiana. Investigators hope that any debris found as far west as California can help them determine where problems began with the orbiter during reentry. The San Francisco Chronicle reported Wednesday that one observer in California photographed what appeared to be a lightning-like streak following the shuttle's plasma trail during reentry; the images have been turned over to NASA for analysis.