Background summary abridged from: Sign Oral History Project,  “History of the United States Air Force UFO Programs (1947-1969),” In particular: Condon’s conclusion was “That nothing has come from the study of UFOs in the past 21 years that has added to scientific knowledge. Careful consideration of the record as it is available to us leads us to conclude that further extensive study of UFOs probably cannot be justified in the expectation that science will be advanced thereby.” On 17 December 1969, Secretary of the Air Force, Robert C. Seamans, Jr. announced the closure of Project Blue Book, echoing Condon that its continuation “cannot be justified either on the ground of national security or in the interest of science.” See: Air Force to Terminate Project “Blue Book”.