Space Shuttle thermal protection system
On February 1, 2003, the Space Shuttle "Columbia" was destroyed on reentry due to a failure of the TPS. The investigation team found and reported that the probable cause of the accident was that during launch, a piece of foam debris punctured an RCC panel on the left wing's leading edge and allowed hot gases from the reentry to enter the wing and disintegrate the wing from within, leading to eventual loss of control and breakup of the shuttle.
Terahertz nondestructive evaluation
STS-114 employed Space Shuttle "Discovery", and was the first "Return to Flight" Space Shuttle mission following the Space Shuttle "Columbia" disaster. It launched at 10:39 EDT, 26 July 2005. During the STS-114 flight significant foam shedding was observed. Therefore, the ability to nondestructively detect and characterize crushed foam after that flight became a significant priority when it was believed that the staff processing the tank had crushed foam by walking on it or from hail damage when the shuttle was on the launch pad or during other preparations for launch.