Flight demonstration of a superpressure balloon by three-dimensional gore design Original Research Article

On May 15, 1999, a balloon with a volume of 3,100 cubic meters was successfully launched from Sanriku Balloon Center of Japan. It became a superpressure balloon at 19.2km in altitude with 20% pressure difference to the ambient atmosphere. This is the first superpressure balloon capable of suspending a heavy payload. It was designed by the new ‘three-dimensional gore design’ method and was based on a pumpkin shape balloon with bulges of small radii between adjacent load tapes without the help of film extensibility. The balloon climbed up to 21.6km in altitude by dropping the ballast and held out against a 64% pressure difference over the ambient atmosphere. This flight test proved the capability of large stratospheric superpressure balloons by this new design method.