HOUSTON - In what could be one of the most significant debris discoveries yet from the shattered Columbia, searchers found a data recorder that may hold valuable clues as to what destroyed the space shuttle, the accident investigation board said Wednesday night. A spokeswoman for the board, Laura Brown, said the ship's recorder was intact but sustained some heat damage. Officials are hoping that temperature and aerodynamic pressure data can be retrieved from its magnetic tape, she said. Brown compared the recorder to an airplane's black box. "We have no way of knowing whether the data can be recovered," she...