W of Tanana, AlaskaFebruary 1959

On February 12, 1959, pilots near Tanana, Alaska spotted an unusual object in the sky. The object was a balloon roughly 50 feet across and about 30 percent taller than it was wide, with a milky-clear appearance. Suspended directly below it was a black or dark gray box, roughly three by three by four feet in size. A cable or rope about 100 feet long dangled beneath the box and was visible from half a mile away.

Multiple fighter jets from nearby Elmendorf Air Base were dispatched to investigate. An F-102 fighter jet piloted by Lieutenant G. H. Meyers was already circling the object when Captain J. J. Voynich arrived in a T-33 trainer jet. During their first attack pass at around 0115 GMT (Greenwich Mean Time), Meyers fired 2.75-inch rockets at the balloon but missed. A second set of F-102 jets arrived shortly after. At approximately 0148 GMT, Captain Y. L. Isbell made a successful firing pass with rockets. The balloon collapsed and began falling rapidly, descending at about free fall speed. The pilots chased the falling object down to about 20,000 feet before it disappeared into haze. The T-33 continued lower to approximately 7,000 feet but lost contact. The balloon was never recovered.

The Air Force's intelligence analysis noted that the balloon was too small to match any known American high-altitude research balloon program, such as the classified Skyhook project. Officials considered it possible that the balloon had drifted into Alaska from Soviet territory or had been intentionally released there, but without recovering and analyzing the equipment box, they could not determine its origin or purpose. The Air Force later abandoned plans to search for the fallen object.

The full case file, consisting of seven pages as held by the National Archives, is reproduced below.