On 11 September 1951, Captain Edward J. Ruppelt took over the reins of Project Grudge; and one month later, a revamped version was established – Grudge II. The Battelle Memorial Institute, a "think-tank" consulting firm, was asked to prepare a statistical study of UFO reports obtained up until that time period. Several months later, in March 1952, Grudge II was officially designated as Project Blue Book – a project that would remain in existence until 1969.

There can be no doubt, however, that the role of Blue Book's mission was radically different to that of both projects Sign and Grudge. For the most part, Blue Book's approach was directed by a panel formed in late 1952 by the CIA known as The Scientific Advisory Panel on UFOs, or more popularly, The Robertson Panel. Although it was determined that there was a distinct lack of evidence to support the notions that UFOs were extra-terrestrial in origin, the Robertson Panel nevertheless felt that UFO sightings represented a potential danger to national security that could be exploited for propaganda and psychological means by the Soviets. It was this concern that prompted the Robertson Panel to conclude that UFO mystery should be demystified. This was to be the role assigned to Blue Book.

Whilst it is true that some staff assigned to Blue Book (such as Edward Ruppelt) were genuinely interested in resolving the UFO mystery and made praise-worthy moves to do so, on many occasions, bizarre and simply inaccurate explanations were offered to try and resolve as many cases as possible. Moreover, despite all the hype that continues to surround Blue Book, it was never anything more than an exercise in public relations and received minimal staffing from one officer, two clerks and a number of typists. Until it was officially terminated in 1969, Blue Book continued to present seemingly adequate explanations to the UFO mystery whilst the real work went on behind the scenes. As evidence of this, consider the following extracted from a 1969 USAF memorandum prepared by Brigadier General C.H. Bolender, the Air Force’s Deputy Director of Development.

“Reports of unidentified flying objects which could affect the national security are made in accordance with JANAP 146 or Air Force Manual 55-11, and are not part of the Blue Book system.”