NASA is moving away from the theory that insulation foam seen to peel away from Columbia's external tank and hit the vehicle's left wing was responsible for the disaster. Ron Dittemore, NASA's shuttle programme manager, has consistently doubted the theory that the foam caused the accident. And at a news conference at the Johnson Space Center, Houston, on Wednesday, he again stated his view that the reason for the disaster lay elsewhere. "It doesn't make sense to us that a piece of debris could be the root cause of the loss of Columbia and its crew," Mr Dittemore said. "There's got to be another reason." Earlier relatives of Israeli astronaut Ilan Ramon, said that the doomed crew of Columbia would have known something was wrong with the spacecraft for more than a minute before it began to break apart.