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.
STS-61-C
STS-61-C saw "Columbia" return to flight for the first time since the STS-9 mission in November 1983, after having undergone major modifications over the course of 18 months by Rockwell International in California. Most notable of these modifications was the addition of the SILTS (Shuttle Infrared Leeside Temperature Sensing) pod atop "Columbia's" vertical stabilizer, which used an infrared camera to observe reentry heating on the shuttle's left wing and part of its fuselage. The camera was only used for a few more missions after STS-61-C, but the pod remained on "Columbia" for the remainder of its operational life. Smaller and more discreet modifications were also added at various points throughout the shuttle. The bulky ejection seats, which had been safed after STS-4, were replaced with conventional seats and head-up displays for the commander and pilot were installed.