it was foam.
And, as I recall, foam that broke away because the original formulation of insulating foam had been changed due to environmental concerns, making it more “environmentally friendly” but weaker.
*it was foam.*
You would be referring to the shuttle Columbia crash in 2003. It also was caused by a top-down politically correct decision to replace the superior CFC-blown polyurethane under-belly foam with the weaker water-blown polyurethane foam on the Columbia.
CFC bad.
I worked at Corning Inc at the time, a division, Erwin Ceramics Plant. The material is actually a ceramic tile with a foam like interior. Very lightweight. About the size of a bar of soap. You can hold it in your hand at one end and get the other end red to almost white hot and not fall the heat.