It was only after considerable deliberation that I put this report together, because it had to be told accurately, with no holds barred. I finally decided to do it for two reasons. First, there is world- wide interest in flying saucers; people want to know the facts. But more often than not these facts have been obscured by secrecy and confusion, a situation that has led to wild speculation on one end of the scale and an almost dangerously blas? attitude on the other. It is only when all of the facts are laid out that a correct evaluation can be made. Second, after spending two years investigating and analyzing UFO reports, after talking to the people who have seen UFO's-- industrialists, pilots, engineers, generals, and just the plain man- on-the-street, and after discussing the subject with many very capable scientists, I felt that I was in a position to be able to put together the complete account of the Air Force's struggle with the flying saucer. The report has been difficult to write because it involves something that doesn't officially exist. It is well known that ever since the first flying saucer was reported in June 1947 the Air Force has officially said that there is no proof that such a thing as an interplanetary spaceship exists. But what is not well known is that this conclusion is far from being unanimous among the military and their scientific advisers because of the one word, _proof_; so the UFO investigations continue. The hassle over the word "proof" boils down to one question: What constitutes proof? Does a UFO have to land at the River Entrance to the Pentagon, near the Joint Chiefs of Staff offices? Or is it proof when a ground radar station detects a UFO, sends a jet to intercept it, the jet pilot sees it, and locks on with his radar, only to have the UFO streak away at a phenomenal speed? Is it proof when a jet pilot fires at a UFO and sticks to his story even under the threat of court-martial? Does this constitute proof? The at times hotly debated answer to this question may be the answer to the question, "Do the UFO's really exist?" I'll give you the facts--all of the facts--you decide. _July_ _1955_, E. J. RUPPELT CHAPTER ONE Project Blue Book and the UFO Story In the summer of 1952 a United States Air Force F-86 jet interceptor shot at a flying saucer. This fact, like so many others that make up the full flying saucer story, has never before been told. I know the full story about flying saucers and I know that it has never before been told because I organized and was chief of the Air Force's Project Blue Book, the special project set up to investigate and analyze unidentified flying object, or UFO, reports. (UFO is the official term that I created to replace the words "flying saucers.") There is a fighter base in the United States which I used to visit frequently because, during 1951, 1952, and 1953, it got more than its share of good UFO reports.