I doubt very much that the Air Force would bother to create illisionary space craft. Why should they? Think about it. There are just too many eye wittnesses to space craft that fly at unreal speeds. If there were just a few sightings from time to time, then it's anyone's guess. I gotta go with the odds. Millions of people can't be lying about the same thing and also, for some interesting reading, look up Billy Meier through google. His story goes back to the 70's ....