The Roswell Report: Fact vs. Fiction in the New Mexico Desert

This flight pattern represents the best approximation to constant level flight that we have obtained with meteorological clusters.

Flights 8 and 11 each employed more than one polyethylene balloon in an attempt to reach higher altitude than possible with the single balloons then available. Figure 39, 40, 41, 44 and 45 show the type and arrangement of balloons and their flight behavior. In both flights, the maximum altitude was not high enough to cause activation of the automatic ballast valve. Consequently, there was no compensation for diffusion other than the steady leakage of ballast through the imperfect seating of the valve. In flight 8, after one hour, this leak was not sufficient to maintain a constant altitude, so the flight terminated. However, in flight 11, constant altitude was maintained at 16,000 ft. 1500 feet for 7 hours until all of the ballast was expended.

Flight 10, in contrast to flights 8 and 11, did reach an altitude at which the automatic ballast control was actuated, resulting in a flight of perhaps more than 26 hours. Although the maximum altitude reached by this heavy spherical cell was 15,000 feet, the ballast control was effective at a level of 9000 feet. The expected difference between activation level and operation level was probably exceeded because of the temperature effect of the air entrapped in the pressure capsule.

Figure 42 shows the train, and figure 43 shows the time-altitude curve for the 512 minutes of radiosonde data.

The oscillations around 9000 feet during the last two hours of data may be attributed to the changing buoyancy of the balloon as cloud masses intermittently shielded it from the sun's rays. An unconfirmed report was received to the effect that this balloon was still floating 26 hours later over Pueblo, Colorado.