Project Grudge Expanded Upon Project Sign
US Air Force's Project Grudge succeeded Project Sign as the second official UFO study.
Project Grudge was an official U.S. government program run by the U.S. Air Force that was successor to Project Sign. The program was tasked with analyzing information on UFO sightings/events. Initiated in 1949, the program lasted about two years before being disbanded by the USAF in 1951, concluding that all UFO sightings ever reported were related to weather phenomena or from terrestrial sources.
