日本は何故、反省しないのか？

Investigators are searching for evidence that a block of ice big enough to damage Columbia's wing may have formed on a waste water vent, a problem that plagued an earlier shuttle flight. They also are looking closely at what may be two key pieces of Columbia debris ・a 2-foot piece of one wing, including an attached chunk of thermal tiles, and a 300-pound cover of a landing gear compartment, possibly the site of a sudden temperature rise moments before the shuttle broke apart.