Connection: Mission To Northwest

The 555th Parachute Infantry Battalion was dispatched to the Pacific Northwest in the summer of 1945 over fears that a Japanese bombing campaign would set the nation’s forests on fire.

The fleets of balloon bombs that Japan hoped would burn down the woods of America failed. Though they landed as far south as Mexico and into Canada, none of them caused a forest fire.

In Washington, one of the balloons did land in the Hanford Engineering works where uranium was being processed for the atomic bomb that would be dropped on Nagasaki.

The balloon became tangled in an electrical line providing power to the cooling pumps of a nuclear reactor. The pumps shut down, but a backup system quickly restored power.

The fleets of balloon bombs that Japan launched were born of an ingenuity with paper and a careful study of the wind and atmosphere.

The 30-foot-diameter balloons were made of 600 sheets of handmade Mulberry tree paper, called washi.

Japanese schoolgirls were enlisted to construct the balloons. They weren’t allowed to wear hairpins or have long nails for fear the paper would be punctured. They wore socks and gloves as further attempts to protect the paper during construction.

Filled with hydrogen, the balloons rode across the Pacific from Japan on a jet stream at 30,000 feet. The winds could move the balloons at more than 100 mph, making the 6,000-mile trip in about three days.

An aneroid barometer was attached to a small platform below the balloon. When the balloon rose above 30,000 feet, the barometer would trigger venting and the balloon sank. When it fell below 3,000 feet, another device dropped sandbags from the platform. After three of these cycles, the floating bomb would crash and explode.

Of an estimated 9,300 balloons the Japanese launched, only 90 are known to have reached the United States.