After reading some of the skeptical responses to NASA's push towards a "space junk" explanation for the Columbia loss, I did a little searching on the web. You see, I recalled a story from several years back explaining how we almost lost a shuttle once before when a tiny speck of space debris pegged one of the shuttles windows and blew out a good sized chunk of glass. In my search for background material to support a post about this, I stumbled across something MUCH better: a National Research Council findings document about the dangers of space junk compiled in...