In a 1985 "Fact Sheet" on Project Blue Book, the Air Force said it declassified the documents after studies of the project determined three things: "(1) no UFO reported, investigated, and evaluated by the Air Force has ever given any indication of threat to our national security; (2) there has been no evidence submitted to or discovered by the Air Force that sightings categorized as 'unidentified' represent technological developments or principles beyond the range of present-day scientific knowledge; and (3) there has been no evidence indicating that sightings categorized as 'unidentified' are extraterrestrial vehicles."