Columbia accident investigators fired a chunk of foam at a sample wing of the space shuttle on Monday, and managed to knock out a 40 centimetre hole. The investigators believe this is the “smoking gun” that proves how events led to the destruction of the space shuttle in February. The impact was so strong that it damaged some of the sensors designed to measure the damage. The board has already made preliminary recommendations about how NASA can improve its policies to reduce risks to the shuttle in the future, but their full report is due later this month.