Project Sign

Project Sign was the United States Air Force (USAF)’s first formal investigation into UFO reports. The USAF Chief of Staff established the project in 1947-12 to investigate the first recorded observations of such objects.¹ Nathan Twining had recommended a detailed study of the phenomena, which became known as Project Sign.² The project was originally named Project SAUCER before being formalised into an official, high-priority programme named Project Sign,³ with the Air Technical Intelligence Center (ATIC) assuming control on 1948-01-23.⁴ According to an employee of Project Sign interviewed by the All-domain Anomaly Resolution Office (AARO), the project in fact began a year earlier, in 1946, under the same informal Project SAUCER name.⁵

The impetus for the investigation was to determine whether the reported objects might be Soviet secret weapons or of “extra-planetary” origin.⁶ As part of this work, Project Sign staff reviewed the military’s intelligence on German weaponry and aeronautical capabilities to determine whether any had fallen into Soviet possession.⁷ Between 1947 and 1949, USAF personnel investigated 243 reported Unidentified Anomalous Phenomena (UAP) sightings.⁸ J. Allen Hynek served as an advisor to the project;⁹ he later said that in his first year on Project Sign the whole issue “seems utterly ridiculous”.¹⁰ Edward Ruppelt, a USAF officer, was privy to the investigations.¹¹

According to the Report on the Historical Record of U.S. Government Involvement with Unidentified Anomalous Phenomena, Volume I, Project Sign concluded in 1949-02 that no definite and conclusive evidence was yet available to prove or disprove the existence of the unidentified objects as real aircraft of unknown and unconventional configuration.¹² The same report states that nearly all of the sightings it reviewed were attributed to misinterpretation of known objects, hysteria, hallucination, or hoax,¹³ and that the project recommended continued military intelligence control over the investigation of all UFO sightings.¹⁴ Project Sign’s overall findings were inconclusive but left open the possibility of extraterrestrial origins for the craft.¹⁵

According to an unsubstantiated historical account derived from a single source, Project Sign staff in 1948-07 drafted, signed, and sent up the military chain for approval a report titled Estimate of the Situation (1948), which allegedly concluded that UFOs were of “interplanetary” origin.¹⁶ The same account holds that staff who leaned towards this interplanetary explanation were subsequently purged from the organisation,¹⁷ and that the report’s rejection may have contributed to Pentagon leadership’s loss of confidence in the Project Sign staff, leading to the establishment of Project GRUDGE (Original Organization).¹⁸ Project Sign was renamed Project GRUDGE in approximately 1949-02,¹⁹ bringing to a close an air force-controlled investigation that had run for one year.²⁰

The USAF’s study of UAP continued through 1948 and 1949 under Project Sign and its successor, Project GRUDGE.²¹ Edward Ruppelt later sought to correct the mistakes of Project Sign and the original Project GRUDGE.²² The reestablished Project GRUDGE (Reestablishment) reviewed all of the earlier cases from Project Sign, the original Project GRUDGE, and the ATIC interim period.²³ A. Ray Gordon subsequently led the CIA Special Study Group 1952, which reviewed all of ATIC’s data from Projects Sign through Grudge.²⁴ Decades later, Luis Elizondo conducted a review of government historical records including Project Blue Book and its predecessors, Project Sign and Project GRUDGE.²⁵