3.5”. Upper left red panel has lost some color intensity and there are a few scuffs and hairline scratches showing in reflected light with little of this showing under normal viewing. Still with nice gloss. He was one of the original seven astronauts in the Project Mercury program. His nine-hour flight took place October 3, 1962 and he became the fifth American and ninth human to rocket into space. He was also the first person to go into space three times and the only person to have flown in the Mercury, Gemini, and Apollo programs. Rare.