LeRoy E. Cain is an American aerospace engineer who worked for NASA as a flight director, launch integration manager and deputy manager of the Space Shuttle Program. Cain may be best known to the public from footage and documentaries showing his work as the entry flight director for STS-107, the mission that ended in the catastrophic disintegration of Space Shuttle Columbia, 1 February 2003. Cain issued the ominous "Lock the doors" command, in a calm voice but a tear running down his cheek, initiating contingency procedures in mission control for the first time since the Space Shuttle Challenger disaster 17 years earlier.