CAPE CANAVERAL, Feb. 3 — Two days before the Columbia disaster, a NASA engineering team sent an internal memo calculating a high probability that launch debris had caused a gash 7½ by 30 inches on the shuttle’s left wing, NBC’s Jay Barbree reported Monday. NASA engineers have talked of a heat spike and drag on the left wing, suggesting a potential problem with the thermal tiles there. But NASA’s chief told NBC News on Monday that the tiles are just one of many variables being investigated.
