Ultra long duration balloons (ULDB), currently under development by the National
Aeronautics and Space Administration (NASA), requires the use of high strength fibers in the
selected super-pressure pumpkin design. The pumpkin shape balloon concept allows clear
separation of the load transferring functions of the major structural elements of the
pneumatic envelope, the tendons and the film. Essentially, the film provides the gas barrier
and transfers only local pressure load to the tendons. The tendons, in the mean time …