Project 10073 Record Card and Associated Correspondence — Greenbay, Wisconsin, 18 September 1961

This document contains a Project 10073 record card and subsequent internal correspondence regarding a UFO sighting reported on September 18, 1961, in the vicinity of Greenbay, Wisconsin. The witness, identified as a civilian, reported observing a large, round, silver object that remained stationary for approximately 15 minutes. The object was estimated to be at an altitude of 80,000 to 90,000 feet. An incoming teletype message (TWX) from Truax Field, Wisconsin, provided further details, noting the object's unusual appearance and its position 50 miles north of Milwaukee. Following the report, Colonel Edward H. Wynn of the Foreign Technology Division requested a review of the sighting. In response, Colonel Paul J. Slocum of the Electronics Division evaluated the data, noting that the object's relatively low speed, high altitude, and erratic course—which included hovering—ruled out a conventional aircraft. Colonel Slocum concluded that the evidence favored a weather balloon and suggested that further investigation should focus on verifying weather balloon launch activities in the area. The documentation includes the original record card, the incoming teletype message, and the internal memoranda between the Foreign Technology Division and the Electronics Division.