On December 17, 1969, Secretary of the Air Force Robert C. Seamans, Jr. announced the termination of Project Blue Book, the Air Force program for investigating UFO reports, after concluding that continued operation was not justified by national-security or scientific value.1
Origin
The closure grew out of a review chain that began before the final announcement. In March 1966, Brian O'Brien's Air Force Scientific Advisory Board ad hoc committee reviewed Project Blue Book, found limited staffing and no verified case outside known science and technology, and recommended deeper university-led scientific investigation of selected sightings.2
The University of Colorado study was created from that recommendation. Edward U. Condon's summary traced the Colorado project directly to the O'Brien committee and said the Air Force Office of Scientific Research selected the University of Colorado as the single contracting university for the work.3
Condon's final conclusions argued that 21 years of UFO reports had not added to scientific knowledge, that a major continuing scientific UFO program was not warranted, and that any defense function could be handled through ordinary intelligence and surveillance operations rather than a special unit like Blue Book.4
The National Academy of Sciences then reviewed the University of Colorado report's scope, methods, and findings. The December 17 DoD release said the NAS panel concurred that no high priority in UFO investigations was warranted by the prior two decades of data and treated extraterrestrial visitation as the least likely explanation on the available knowledge.15
Who
Seamans made the formal decision as Secretary of the Air Force and addressed it in a memorandum to Air Force Chief of Staff General John D. Ryan.1
The announcement named four bases for ending the program: the Colorado study, the NAS review, earlier UFO studies, and Air Force experience investigating reports over the previous two decades.1
The same release identified Condon as director of the University of Colorado study, cited the 1953 Robertson Panel and the 1966 O'Brien review as prior studies, and summarized Project Blue Book's institutional conclusion that evaluated UFO reports showed no national-security threat, no demonstrated technology beyond then-current science, and no evidence of extraterrestrial vehicles.1
How evolved
The Air Force's immediate plan was administrative rather than investigative expansion. The December 17 release said Blue Book records would be retired to the USAF Archives at Maxwell Air Force Base, while information requests would continue through the Secretary of the Air Force Office of Information.1
Later Air Force public summaries framed the decision as the end of the regulation and office structure that had governed UFO investigation. The Air Force Declassification Office says the project, headquartered at Wright-Patterson Air Force Base, ended with 12,618 reports received and 701 left unidentified, while the controlling regulation was rescinded after closure.6
NARA's Project Blue Book reference page says the Air Force retired the declassified records to the custody of the National Archives, where textual records, case files, administrative files, OSI-related material, indexes, microfilm, photographs, motion picture film, sound recordings, and still pictures became available for research.7
NARA's fiftieth-anniversary account adds that the records were transferred into National Archives custody in 1975, redaction work to protect personally identifiable information concluded in spring 1976, and public research access then shifted the files from an active Air Force investigation system into archival holdings.8
The public consequence was that the Air Force no longer received, documented, or investigated UFO reports through Wright-Patterson, and callers were directed toward local law enforcement or private and professional organizations rather than a federal Blue Book intake process.7
Modern UAP framing keeps Blue Book as both a closed historical program and a record source. AARO's 2024 historical report describes Project Blue Book as the longest-running U.S. UFO or UAP investigation, says AARO partnered with NARA to review 7,252 Blue Book files containing 65,778 digital records, and repeats the Air Force's finding that 701 of 12,618 reports remained unidentified without proving national-security threat, advanced technology, or extraterrestrial vehicles.9
NARA's current UAP research pages likewise place Blue Book inside a wider UFO and UAP archival landscape, listing Project Blue Book administrative files, case files, sanitized case files, artifacts, OSI-related records, and bulk-download catalog exports under broader records related to UFOs and UAPs.10