Flight 88: Released from Alamogordo, New Mexico, 1241 MST, August 25, 1948
Recovered at Lovington, Texas
This flight was planned to measure the diffusion and leakage of lifting gas through a 20-foot, .001" polyethylene balloon at 40,000 feet. A fixed-leak orifice was set to flow at 100 grams per hour, and an automatic ballast valve was included to supply more ballast as demanded. This automatic valve broke on release, and the flow of 100 grams per hour was not sufficient to keep the balloon and equipment up.
Temperature data on this flight was obtained from thermistors inside the balloon, inside the battery and in the free air. These data and the height-time curve are shown in Figure 38. During the period from 1400 to 1530 when
[figure]
Figure 38
the balloon was slowly descending, the temperature of the gas increased with respect to the free air temperature, and a differential of 15°C was recorded at 1530. With subsequent, more rapid descent, this differential was reduced, presumably by ventilation. The battery box temperature remained above 100°C after four hours aloft.
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