Project Grudge

Project Grudge was the U.S. Air Force's UFO investigation from February 1949 until it became Project Blue Book in March 1952. Its name has become shorthand for institutional debunking.

Grudge replaced Project Sign after the internal defeat of Sign's extraterrestrial-leaning analysts. The new posture, by most historians' reading, started from the premise that reports had conventional explanations and worked backward.

Grudge produced its major report in August 1949, evaluating 244 cases and attributing them to misidentifications, hoaxes, and psychological factors, while conceding 23 percent remained unexplained, a figure buried in the text. It recommended reducing the project's scope. Grudge then went largely dormant, doing minimal investigation, until the July 1952 sighting surge and internal criticism revived serious work. Edward Ruppelt, who took over in late 1951 and reorganized the effort into Blue Book, described the Grudge era as the project's "dark ages," writing that reports were evaluated on the premise that they could not exist. The project also commissioned the first press-managed treatment of the subject, cooperating with a Saturday Evening Post series presenting saucers as explainable.

Ruppelt is the era's chief chronicler. Hynek continued astronomical screening. Various rotating officers ran the diminished project.

Defunct since 1952; files at the National Archives.

Grudge is the historical anchor for the claim that official investigation was designed to dismiss. Skeptics partly agree with the description while disputing the motive, noting the Air Force's actual concern was Soviet aircraft and public panic, not hiding aliens, and that most reports genuinely were misidentifications. The unexplained-case residue that Grudge's own report contained became ammunition for critics from Keyhoe onward.