Flight 11: Released from Alamogordo, New Mexico, 0508 MST, July 7, 1947
Not recovered
On this flight a 15-foot, .008" wall, polyethylene balloon was combined with a cluster of six small plastic cells (7-foot diameter, .001" wall) to lift a total load of 35 pounds as high as possible (Figure 7). The small
[figure]
Figure 7: Train, Flight 11
cells did not rise as fast as the large balloon; consequently, three of them were inverted and filled with air.
With this loss of lift, the altitude reached was only about 17,000 feet MSL, and the automatic ballast valve (set to operate at 45,000 feet) was not activated. This flight demonstrated the need for a minimum-pressure switch
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