The Fu-Go (fire balloon) was a huge hydrogen balloon loaded with incendiary bombs. The plan was to release the balloons into the jet stream over the Pacific Ocean. Between November 1944 and April 1945, Japan launched more than 9,300 Fu-Go balloons. The President asked the press to keep the deaths a secret so that the Japanese would not know about their success. Because of the news blackout, the Japanese believed that none of their Fu-Go balloons was successful, so they gave up the program. The Ku-Go program was the Japanese effort to create a death ray. An article published in The New York Times in 1934 caught the attention of some Japanese scientists. However Tesla never showed anyone the device and it was never proven to exist. That didn’t stop Japanese scientists from trying to build their own death ray or Ku-Go. The Japanese experimented with magnetrons to develop high power microwaves.