I was curious about this too and asked on Reddit, which got a variety of answers (and good terms to search for!) if you're interested in finding out more: http:

I was curious about this too and asked on Reddit, which got a variety of answers (and good terms to search for!) if you're interested in finding out more: http://www.reddit.com/r/askscience/comments/26idyd/why_werent_the_space_shuttles_tiles_as_smooth_as/ http://www.reddit.com/r/askscience/comments/26idyd/why_weren...