Arnold Schwarzenegger could have played a very different science fiction icon. Long before Star Wars or Star Trek took over the world, Flash Gordon was the definitive space opera experience. It was Alex Raymond who launched it as a comic strip back in the 1930s, and within a few years, it had spun off into serials, novels, and toy lines. It also ended up inspiring an entire generation of future filmmakers, most notably George Lucas. The irony is…