Empirepage.com - Guest Editorials: "Why did the shuttle's foam insulation flake off? In response to an edict from the EPA, NASA was required to change the design of the thermal insulating foam on the shuttle's external tank. They stopped using Freon, or CFC-11, in order to comply with the 1987 Montreal Protocol, an agreement designed to head off doubtful prognostications of an environmental disaster.

But it was the elimination of the old foam that led to a real disaster for the shuttle program. The maiden flight with the new foam, in 1997, resulted in a ten-fold increase to foam-induced tile damage. The new foam was far more dangerous than the old foam. But NASA "