 During World War II, at the request of Vannevar Bush, Cooper took a position in the Office of Scientific Research and Development.He also returned to Washington in 1973, when he was selected to form a panel of six experts charged with investigating the famous 18-minute gap in the White House office tapes of President Richard Nixon related to the Watergate scandal .Cooper was the President and Director of Research at Haskins Laboratories from 1955-1975.