Project 10073 Record Card and Incident Report — Grenier AFB, 29 August 1951

On August 29, 1951, at approximately 15:15 E.D.T., four airmen from the 133d Fighter-Interceptor Squadron stationed at Grenier Air Force Base in Manchester, New Hampshire, observed an unconventional aerial object. The sighting lasted for 15 minutes. The witnesses described the object as consisting of two silvery, spherical components connected by a dark, unidentified body, with one end appearing larger than the other. The object was initially seen descending slowly in an area eight miles away, reaching an altitude of approximately 10,000 feet, which was described as being halfway between the cloud layers. Subsequently, the object rose at a rate of 1,000 to 2,000 feet per minute until it disappeared into a layer of cirrus clouds. Weather conditions at the time included 2/10 coverage of cumulus clouds at 4,500 feet and 8/10 coverage of cirro-stratus clouds at 20,000 feet, with 12 miles of visibility in haze. The wind at 10,000 feet was reported as coming from the northwest at 12-15 MPH. No sound was reported, and no radar contact was made. The incident was formally documented on a Project 10073 record card and forwarded through military channels to the Air Materiel Command at Wright-Patterson Air Force Base. The official conclusion reached by the evaluating authorities was that the object was possibly a balloon with a payload attached. However, because the speed, size, and course of the object remained unknown, the case was ultimately evaluated as having insufficient data for a definitive identification.