Desc: The Great Balloon Bomb Invasion: Directed by Stuart Chait. With Martin K.A. Morgan, Ed Fritz, Renaldo Evans, Ross Coen. From 1944-1945, Japan launched more than 9,000 bomb-laden balloons over the Pacific Ocean to attack the American mainland. Historian Martin Morgan leads a first-of-its-kind hunt to find bombs still lying undetected on North American soil.