Question: When were the astronauts for the first manned space program of the United States announced? 
Sentence (from "Gordon Cooper"): Leroy Gordon "Gordo" Cooper Jr. (March 6, 1927 – October 4, 2004), (Col, USAF), better known as Gordon Cooper, was an American aerospace engineer, test pilot, United States Air Force pilot, and one of the seven original astronauts in Project Mercury, the first manned space program of the United States.
Relevant evidence: Yes