Mercury-Atlas 6 (Friendship 7)

On February 20, 1962, John Glenn lifted off atop an Atlas rocket and became the first American to orbit the Earth. Over four hours and 55 minutes, Friendship 7 completed three orbits while Glenn reported on the strange beauty of orbital sunsets and mysterious ‘fireflies’ — ice crystals glinting outside his window.

The flight was not without drama: a faulty sensor suggested the capsule’s landing bag had deployed early, which would have meant a loose heat shield. Mission control had Glenn keep his retrorocket pack strapped on through reentry as a precaution. He splashed down safely near Grand Turk Island, and America finally had an orbital spaceflight program to rival the Soviet Union’s.