roswell

this switch a circuit is closed when the rate of descent ex-
ceeds l/5 mb/minute, allowing ballast to flaw. ·~e record of
Flight 97 indicates that good control was obtained for a four-
hour period using this switch. However, the instrument is so
delicate and susceptible to temperature effects that its usr3 is
not advised.
E. Flight Simulation
To make laboratory tests on the control equipment just described, a
flight-simulation chamber has been built combining a bell jar and a
temperature chamber. A drawing of the temperature chamber designed
and built at New York University is shown in Figure 17. (Investi-
LowiiT Woa••M• Tru...... -65. Tc.-.-7\_ .... ~;
ACCVRAc;y OF TI.MP: CoKTAc.it.. 0 .•~ ··c
Figure 17. Temperature control chamber.
gation of commercially .sold chambers showed that the c.ost of pur-
chasing a temperature chamber of the size desired would be pro-
hibitive.) First designs called for the use of a freon refrigerating
system; however, use of dry ice as a coolant proved to be more ad-
vantageous. This chamber, with its automatic control, can hold
temperatures a~ high as •lOOOF and as low as -900F within SOfor a
period of several hours. Dry ice consumption at -GOOF is approxi-
mately 150 pounds for a 24-hour period.
It is possible, using a bell jar for flight-similitude studies,
to arrange switches so that the vacuum pump is turned off and on at
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