Armstrong was later assigned as commander of Apollo11, the first U.S. attempt to land on the Moon. On July 20, 1969, Armstrong and lunar module pilot Edwin E. Aldrin landed the Apollo 11 lunar module Eagle on the Moon at the Sea of Tranquility. At 10:56:20 pm Eastern Daylight Time (EDT), he planted his left foot on the lunar surface and proclaimed: "That's one small step for [a] man, one giant leap for mankind." He later said that he intended to say "a," but tape static leaves this uncertain. After serving as deputy associate administrator for aeronautics, Armstrong retired from NASA to be a professor of engineering at the University of Cincinnati (197179) and thereafter a computer company executive. In 1986 he served as vice-chairman of the presidential commission appointed to investigate the destruction of the Space ShuttleChallenger in January 1986.
Bibliography: Crocker, Chris, Great American Astronauts (1988).