I’m wondering if the heat shields now contain some kind of “environmentally friendly” substance that isn’t as durable under extreme conditions like the Mercury, Gemini, and Apollo heat shields were. It’s happened before, with the Shuttle. Foam insulation on the Shuttle’s external fuel tank came loose on launch and impacted the leading edge of Columbia’s wing. We know what happened there…
From wiki:
AVCOAT was used for the heat shield on NASA’s Apollo command module.[5] In its final form, this material was called AVCOAT 5026–39
I should have read farther, also from wiki:
Although AVCOAT was not used for the Space Shuttle orbiters, NASA is using the material for its next generation Orion spacecraft.[6] The Avcoat to be used on Orion is reformulated to meet environmental legislation that has been passed since the end of Apollo