On November 3, 1944, Japan released fusen bakudan, or balloon bombs, into the Pacific jet stream. They each carried four incendiaries and one thirty-pound high-explosive bomb. Japan’s latest weapon, the balloon bombs were intended to cause damage and spread panic in the continental United States. The balloons would claim six American lives on May 5, 1945, but they were widely considered a military failure. Japan halted the operation in April 1945.
Creation of the Fu-Go
The Japanese Military Scientific Laboratory originally conceived of the idea of balloon bombs in 1933. Their Proposed Airborne Carrier research and development program explored several ideas, including the initial idea of balloon bombs, according to Robert Mikesh. His scholarly report on these Fu-Go balloons is a definitive work on this obscure topic.