Probably Not a UFOOne afternoon in late August 1961 I was flying as ECM and Radar operator aboard a Navy radar Constellation out over the Atlantic on the North Atlantic Barrier. We were returning from a barrier run from Argentia, Newfoundland, to the Azores and return and were a couple hours east of Argentia. The BMEWS radar at Thule was wiping out all the potential ECM targets so I was checking out the APS 45 height finder radar. The radar was operating as expected when I noticed a fast moving target at 90,000 feet heading west. I called the chief air control operator who tagged this bogey going 1800 mph a hundred miles south of us heading about 250 degrees. His position was about 40 west and 40 north. This would be from anywhere Europe to the central US coast. This was reported to NORAD and acknowledged.Since then I have tried to find out what this bird was. The A-1 was in development and its successor the SR-71 was a couple years later. The B-45 and the Vigilante did not fly this high or fast so far as I know. I asked Wright-Patterson Air Museum and the National Aerospace Museum with no reply. Do you have any idea what it was? I bet it was one of our planes from the skunk works but I find nothing in the literature in 1961.