Ground test of a stratospheric balloon

On 2020-09-23, together with Włodzimierz Tarnowski, we conducted a ground test of a 300g stratospheric balloon, manufactured by Kaysam Worldwide Inc. in… 1996. The aim was to research the maximum size of the balloon just before burst, and thus to check, whether after 24.5 year of storage, the balloon will retain its parameters specified by the manufacturer. Particularly, if it is possible to inflate it to reach a nominal diameter of 4 meters.

To better illustrate the degree of expansion of the balloon, see below a photo of the original 12x9x8 cm packaging.

After just over half an hour of inflating, the balloon looked like in the picture below…

… and after an hour like this:

After 5.5 hours of inflating (very slow expansion of the balloon envelope) and reaching a diameter of about 5 meters, which is 125% of the nominal value specified by the manufacturer, the balloon looked as follows:

The moment of the explosion itself was as follows:

The moment just before the balloon envelope burst and the first 13 hundredths of a second were captured in the following photos:

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0,03s

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The experiment allowed to collect data on physical parameters during the expansion of the balloon envelope and a series of observations, including the moment of its bursting, which was surprisingly smooth. It also came as a surprise that despite the passage of twenty-four and a half years from the balloon’s production, it still maintained its parameters.