Flight 80: Released at Alamogordo, New Mexico, 1126 MST, July 24, 1948
Recovered at Rincon, New Mexico
On this flight an automatic ballast valve activated by a minimum-pressure switch was used to support a .001", 20-foot polyethylene balloon. From the height-time curve (Figure 33) it may be seen that the balloon remained at its maximum height for two hours, then began to descend slowly. A ballast meter was in use, and no ballast flow was recorded until the balloon descended to about 30,000 feet. It is likely that the mercury minimum-pressure switch was frozen at the higher levels, or that the squib which the switch controlled failed to detonate until a higher pressure was reached.
[figure]
Figure 33
Following the activation of the aneroid capsule of the automatic ballast valve, ballast was released in four separate blocks. With each flow of ballast except the fourth, the balloon was returned to the seal-off pressure of the aneroid with no change in this pressure (321 mb=28,500 feet). The fourth ballast-flow period lasted until the balloon had risen to 300 mb (30,000 feet) and ballast cut off there. Since the sun had set between the third and
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