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

6. altitude the pen passes to the insulator portion of the commutator and ballast flow ceases. Whenever the balloon system subsequently descends past control altitude, ballast is made to flow, maintaining the balloon altitude at control level. This system has been used successfully on over twenty constant level flights maintaining altitude to close limits for periods up to 60 hours. An example of a flight made with this control is shown as Fig. 3. [figure] Fig. 3 Constant Level Balloon Flight Using Ballast Control