In December 1944, David Hambling explains (in Swarm Troopers), US military observers on the West Coast reported a wave of unidentified flying objects:
On investigation, these were found to be paper balloons thirty feet across.
[…]
The balloons were filled with hydrogen and had a complex mechanical gondola. At first, they were thought to be weather balloons, but after reports of unexplained explosions, one was captured intact and found to be carrying incendiary bombs. This was the Japanese Fu-Go or “windship weapon.”
[…]
It was months before intelligence revealed they had flown all the way from Japan. The Japanese were taking advantage of a newly discovered natural phenomenon, the jet stream, a narrow ribbon of fast-moving air at high altitudes.
[…]
A clockwork mechanism controlled the release of a set of small sandbags around the rim of the gondola. Whenever the balloon fell too low, it dropped another sandbag. If it rose too high, which might cause it to burst, a valve vented a small amount of hydrogen. This control system meant it maintained height and stayed in the jet stream for the three-day journey across the Pacific.
[…]
The aim was to start forest fires in the heavily wooded regions of the Pacific Northwest. This would spread panic and divert resources from the war effort. The target was big enough that even this rough method of aiming had a chance of success.
[…]
US analysts estimated the Fu-Go cost $ 200 each, at a time when a P-51 Mustang was $ 50,000. The little balloons were hard to intercept. There was not enough metal on them to show up on radar, and they were surprisingly fast at high altitude, making them difficult to catch. Only around twenty were shot down.
[…]
At least four hundred Fu-Go made it to America, scattered from Mexico to Canada. The number would have been greater but for a problem with antifreeze in the altitude control system. This was too weak and the altitude controls were apt to freeze up, leaving Fu-Go to slowly descend into the waters of the Pacific.
After the war, the US considered balloons:
The E77 balloon bomb was similar to the Fu-Go, but delivered an anti-crop agent in the form of feathers dipped in a bacterial or fungal culture. Like the Fu-Go it was an imprecise way of hitting a large target, but 1954 tests suggested that balloon bombs would be effective.
[…]
The US also tested long-distance balloons for photographing enemy territory, but again balloons were edged out by manned aircraft. As always, the US military took more interest in high-performance manned aircraft than small, unmanned alternatives.
Ain’t money, it’s people, and time, and people’s wasted time. They could have been employed elsewhere and elsewise.
F– money, it’s the PEOPLE.
A great article related to this is about the Loon (JB-2), the American clone of the German V-1 buzz bomb. It has cost-benefit analysis on both bombs and aircraft. No wonder the Loon was the 3rd priority in aviation after the B-29 and jet technology, although mostly abandoned post war. Is it discussed in the swarm troopers book?
https://wwiiafterwwii.wordpress.com/2023/12/24/merry-christmas-2023-a-look-at-the-loon/
No, Anonymoose, Swarm Troopers does not mention the JB-2 Loon. You’ve piqued my interest.