Shuttle didn't use ablative heatshields. They had to check - that is, detach, disassemble etc. - engines, which added to delays and costs.
[−]burnerRhodov3 · 2026-11-15 Sun 17:47 UTC ·
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They used ablative materials at multiple spots on the shuttle, mainly in the a elevon gaps and around the nose. They also used carbon on carbon on all the wing edges, which is super expensive, but lasts a long time in theory but you have to scrap the whole section if it cracks.