roswell

of 170 grams per hour. A balloon o£ this type with no alti-
tude control stayed aloft for more than two hour• and atter
reaching ceiling. the altitude did not vary by more ~
1500 feet while the balloon was within range of the ebaeninl
station.
The preparation and launching techniques di.au1&ed tor the
20-foot balloon apply also to the 30-foot cell. No fu~th•r
discussion is required for the 30-foot balloon.
The 70-foot balloon seen in Figures 41 and 42 is launched in
the same manner as the 20-foot cell. A much larger amount
of gas is required and since it is valved rapidly into the
balloon, it has been found necessary to pass the gas through
a heating coil to prevent it from reaching the balloon so
adiabatically cooled as to be incapable of lifting the
load. This heater is shown in Figure 43. Due to the large
lift and area exposed to the wind at launching, the large
cell may be dangerous if personnel attempt to hold the gear
or act as anchors. If possible, al} gear ..should be laid out
downwind to be picked up from the ground by the balloon. The
anchor should be a winch mounted on a truck which can move
around the balloon so as to be downwind at launching.
Since the altitudes where the 70-foot balloons normally float
are high in the stratosphere, the natural stability of the bal-
loon in the temperature inversion keeps these cells up for
a long period of time without ballast or other controls. One
such flight fell slowly during a period of 75 houra and was
still above 65,000 feet when the barograph record ended.
-75-