One of the original Mercury Astronauts and the last American to fly in space alone. On May 15, 1963 he shot into space in a Mercury capsule for a 22 orbit journey around the world. During the final orbit, Major Gordon Cooper told the tracking station at Muchea (near Perth Australia) that he could see a glowing, greenish object ahead of him quickly approaching his capsule. The UFO was real and solid, because it was picked up by Muchea's tracking radar. Cooper's sighting was reported by the National Broadcast Company, which was covering the flight step by step; but when Cooper landed, reporters were told that they would not be allowed to question him about the UFO sighting.
Major Cooper was a firm believer in UFOs. Ten years earlier, in 1951 he had sighted a UFO while piloting an F-86 Sabrejet over Western Germany. They were metallic, saucer-shaped discs at considerable altitude and could out-maneuver all American fighter planes. Major Cooper also testified before the United Nations: "I believe that these extra-terrestrial vehicles and their crews are visiting this planet from other planets... Most astronauts were reluctant to discuss UFOs." "I did have occasion in 1951 to have two days of observation of many flights of them, of different sizes, flying in fighter formation, generally from east to west over Europe."
And according to a taped interview by J. L. Ferrando, Major Cooper said: "For many years I have lived with a secret, in a secrecy imposed on all specialists in astronautics. I can now reveal that every day, in the USA, our radar instruments capture objects of form and composition unknown to us. And there are thousands of witness reports and a quantity of documents to prove this, but nobody wants to make them public. Why? Because authority is afraid that people may think of God knows what kind of horrible invaders. So the password still is: We have to avoid panic by all means."
"I was furthermore a witness to an extraordinary phenomenon, here on this planet Earth. It happened a few months ago in Florida. There I saw with my own eyes a defined area of ground being consumed by flames, with four indentions left by a flying object which had descended in the middle of a field. Beings had left the craft (there were other traces to prove this). They seemed to have studied topography, they had collected soil samples and, eventually, they returned to where they had come from, disappearing at enormous speed... I happen to know that authority did just about everything to keep this incident from the press and TV, in fear of a panicky reaction from the public."
Donald Slayton
Donald Slayton, a Mercury astronaut, revealed in an interview he had seen UFOs in 1951: "I was testing a P-51 fighter in Minneapolis when I spotted this object. I was at about 10,000 feet on a nice, bright, sunny afternoon. I thought the object was a kite, then I realized that no kite is gonna fly that high." As I got closer it looked like a weather balloon, grey and about three feet in diameter. But as soon as I got behind the darn thing it didn't look like a balloon anymore. It looked like a saucer, a disk. About the same time, I realized that it was suddenly going away from me - and there I was, running at about 300 miles per hour. I tracked it for a little way, and then all of a sudden the damn thing just took off. It pulled about a 45 degree climbing turn and accelerated and just flat disappeared."