Project Blue Book was one of a series of systematic studies of Unidentified flying objects (UFOs) conducted by the United States Air Force (U.S.A.F.). Started in 1952, it was the second revival of such a study. A termination order was given for the study in December 1969, and all activity under its auspices ceased in January 1970.
Air Force History’s Referencing UFOs in the Blue Book Era
History of the Directorate of Intelligence June 1 – December 31 1952 [13 Pages, 3MB]
Lessons Learned, Headquarters, 52d Combat Aviation Battalion, 22 September 1969 [54 Pages, 3MB] – It is unclear if this document is part of the Blue Book system. It does confirm, however, that towards the end of the Blue Book era, military installations were still seeing UFOs – some they were later able to identify – while others they were not.
Other Related Documents
Project Blue Book FBI File [13 Pages] – This small file relates to an Air Force program for the investigation of Unidentified Flying Objects. The Secretary of the Air Force discontinued this program in 1969.
Project Blue Book Records, Air Force Missile Development Center, 1947-1970 [42 Pages, 5.18MB] – These documents were obtained from the Air Force Historical Research Agency (AFHRA).
Review of the University of Colorado Report on Unidentified Flying Objects by a Panel of the National Academy of Sciences – The ad hoc committee concurs with the findings of the report of the University of Colorado entitled ‘Scientific Study of Unidentified Flying Objects,’ Dr. Edward U. Condon, Scientific Director. Panel agrees that a study of UFOs in general is not a promising way to expand scientific understanding of the phenomena, and adds: ‘On the basis of present knowledge the least likely explanation of UFOs is the hypothesis of extraterrestrial visitations by intelligent beings.’
Unidentified Aerial Objects Project “Sign” [55 Pages, 19.8mb] – This is the best copy available, which was obtained by the DTIC.