Flight 81: Released from Alamogordo, New Mexico, O548 MST, August 6, 1948 Not recovered
The balloon flown on this flight was made of .004" polyethylene, and it was eggplant shape about 20 feet in diameter and 25 feet long. The first of its kind, this balloon was made by Goodyear Tire & Rubber Company, Inc.
Only a short period of radio reception was obtained, but during this time the balloon rose with predicted speed (500 feet per minute) nearly to its predicted altitude (40,000 feet) and floated within 1500 feet of the 37,000-foot level. Figure 34 is the height-time curve for this flight.
Figure 34
Since the balloon did not descend far enough below its maximum altitude to activate the minimum-pressure switch and the automatic ballast valve, no ballast flow data was telemetered while the balloon was within the radio range. This indicates a very low rate of gas loss through the walls of this balloon.