In 1961, the U.S. came in a close second in the race to put a man in space but laid the groundwork for missions to the moon. Shepard had key roles throughout the era.
The U.S. wasn't far behind, however. Just over three weeks later, at 9:34 a.m. ET on May 5 of that year, NASA launched the second human and first American into space, a 37-year-old U.S. Navy test pilot named Alan Shepard.
"[Shepard] was surprised by the smoothness of the liftoff," according to the NASA account. "The ride continued smoothly for about 45 seconds; then the rocket, capsule, and astronaut began vibrating. Conditioned to these circumstances, Shepard realized that he was passing through the transonic speed zone, where turbulence built up."
The pressure suit kept Shepard relatively cool at about 75 degrees Fahrenheit, compared with 91 degrees in the cabin proper--and the 220 degrees of the capsule's exterior. The maximum gravitational load he experienced during acceleration was 6.3 G, and the ascent speed reached 5,134 miles per hour.
This week, in commemoration of the 50th anniversary of the Freedom 7 mission, the U.S. issued a stamp honoring Shepard.