And as long as we're on the subject, your recommended viewing for this evening is "Battle Beneath the Earth" (1967) -- The stirring saga of the Red Chinese Communists attacking the United States by digging underground tunnels from China to the U.S. and planting nuclear bombs under major cities! No balloons required! Catch Ed Bishop in this B movie classic, who would later star in the "UFO" television series. Available now (probably only to U.S. viewers), on Tubi TV: https://tubitv.com/movies/622412/battle-beneath-the-earth