Fli~a 2~ through. 39: 'l'hey were made from Alamogordo, New Mexico during
Wove er and December, 1947 to test ballast controls and to develop a
launching technique satisfactory for high winds. The period of data re-
ception by radio 'W&.S too short in all of' these flights to permit much e"Y8.lua-
tion of the altitude controls. On three flights (33, 35 and 39) a Fergusem
meteorograph was added to the train to record flight pressure; of 11 balloons
released, only these three were not recovered.
On seven flights the pressure signals reoeind by radiosonde were lost
while the balloon was still rising; Flight 38 was a shrouded neoprene
balloon which burst as 1t became .fullJ and Flight 39 was a polyethylene
balloon which burst at or near its ceiling f'ollowing a very rapid rise.
( 1his was the first balloon to burst using a short external appendix with
stiffeners.}
On the .other two flights (30 and 35) a very short period of level flight
was recorded before the balloon-borne radio transmitter passed out of range.
Besides these two, several other .001" polyethylene
were maintained at constant or near-constant levels for
can be seen from their points or recovery (Figure 13).
seen descending 18 hours after release.
Figure 13
balloons probably
several hours, as
One balloon was
On Flights 29 through 33 only a fixed ballast leak was used, set for
flows of from 300 to 600 grams per hour. Other fllghtl used automatic
ballast controls. Although these fixed leaks seemed to be sufficient to keep
the balloons aloft, there was no clear evidence as to what amount would be
needed for most efficient operation. The need for a system of ballast
metering was indicated in this series o.f flights.
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