Design considerations and practical results with long duration systems for manned world flights Original Research Article

This paper describes development of three balloon types by the author, all proposed for piloted flights around the world. The first was a superpressure pumpkin used to cross Australia. However, the balloon took up an incorrect shape when inflated. Because of this and other problems, the pumpkin was abandoned and the author built a combined helium-hot air balloon. This in turn was abandoned because it was cumbersome and costly. The author then developed an entirely new system, carrying cryogenic liquid helium to create lift in flight. Two very successful 24-h flights were made. In addition several inventions were developed for crew safety. Perhaps the most important is an entirely new way to protect pilots against sudden cabin pressure loss, with potentially broad use.