Atlas LV-3B

Mercury-Atlas 6 climbs past its tower at Cape Canaveral on February 20, 1962, with John Glenn aboard Friendship 7. Three orbits later he was the first American to circle the Earth. Where the Redstone could only lob a capsule up and back down, the Atlas, adapted from an intercontinental missile, had the power to put one in orbit. It is the step that made the Mercury program a true orbital program.