born Nov. 18, 1923, East Derry, N.H., U.S. died July 21, 1998, Monterey, Calif. U.S. astronaut. He graduated from the U.S. Naval Academy and served in the Pacific during World War II. In 1959 he became one of the original seven Mercury program astronauts. In May 1961, 23 days after Yury A. Gagarin became the first human to orbit Earth, Shepard made a 15-minute suborbital flight that reached an altitude of 115 mi (185 km). He later commanded the Apollo 14 flight (1971), the first to land in the lunar highlands. Retiring from NASA and the navy in 1974, he entered private business