Alan Bartlett Shepard, Jr. (November 18, 1923 – July 21, 1998) was an American naval aviator, test pilot, flag officer, and NASA astronaut who in 1961 became the second person, and the first American, in space. This Mercury flight was designed to enter space, but not to achieve orbit. Ten years later, at age 47 the oldest astronaut in the program, Shepard commanded the Apollo 14 mission, piloting the lander to the most accurate landing of the Apollo missions. He became the fifth person to walk on the Moon, and the only Mercury astronaut to walk on the moon. During the mission he hit two golf balls on the lunar surface.