Flight 79: Released from Alamogordo, New Mexico, 1614 MST, July 23, 1948
Recovered at Alamogordo, New Mexico
This was the third attempt to use a coated nylon balloon, sealed off with a valve in the bottom. From Figure 32, the height-time curve, it may be seen
[figure]
Figure 32
that this balloon did not remain aloft very long but that a high degree of superheat was generated in the lifting gas, despite the aluminum coating of the balloon.
The automatic ballast controls included in the flight equipment were inoperative, and as soon as the balloon lost its initial excess buoyancy (corresponding to the super-pressure maintained behind the safety valve) it descended. From the speed of the descent it was computed that an accelerating force equal to 5% of the gross load (52 kg) was acting to bring the balloon down. This force was in turn derived from the loss of lift encountered when over 30°C of superheat was lost by ventilation.
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