signals may be arranged so as to consume a very small portion of transmission time.
D. The duration of radio reception and of positioning data may be greatly extended by appropriately equipped aircraft. It is intended to utilize a B-17 with top-mounted radar to search above the plane for tracking. Depending upon the noise-level encountered, it may be possible to acquire pressure data with a receiver in the plane. It may be necessary to provide at least two aircraft for continuous reception over long periods.
2. It is very desirable that the simplified light-weight ballast control system for flights of less than 24 hours' duration be perfected. The elaborate ballast assembly with the automatic ballast valve will not be needed for the many contemplated flights which will be made with a useful life of less than eight hours. A lower-capacity reservoir with manual ballast valve and filter provides a light-weight, inexpensive unit. Tests are now being conducted to find the best design for these components.
3. In order to float a balloon at a pre-selected maximum altitude it is necessary to supplement the variation-of-ballast with a new height control system.
A. With a given balloon, and given total load, it is possible to forecast the maximum height. (See Section III for the computation.) If various maximum heights are desired, this maximum height may be varied by varying the total load, or varying the bouyancy of the balloon through variation in balloon volume.