Purpose of the flight and payload description
The objective of the experiment was to examine the correlations of the infrared intensity with the auroral zone X-rays, cosmic noise absorption, magnetic disturbances and visible light. The measurement of the IR intensity also allowed to investigate the total energy supplied to the aurora, and the fraction of this energy that was carried by the electrons producing the X-rays that reach balloon altitudes.
An uncollimated NaI scintillation counter, 2,54 cm in diameter by 1,27 cm in height, was used for the detection of X-rays. A three channel integral pulse-height analyser was used to obtain the counting rates for all X-rays of energy greater than 25, 50 and 100 keV. A lead sulfide photoconducting detector -which was covered by a Corning 7-57 glass filter in order to block visible radiation- measured the integrated intensity of infrared radiation from the sky. It was necessary to interrupt periodically the radiation striking the detector in order to obtain a usable signal-to-noise ratio; a rotating chopper blade was used for this purpose.
A blocking plate was provided over the detector to avoid the detection of radiation reflected by the balloon. The figure at left shows the placement of the detector and its associated devices in the instrument package of the balloon. In this position, the detector's effective field of view was 9.6 x 10-2 cm2 steradian, centered on the zenith.
The instrument packages containing the infrared and X-ray detectors and a telemetry system were carried to an altitude of about 30 km by 135.000 cubic feet, polyethylene balloons.
Details of the balloon flight
Balloon launched on: 10/3/1964 at 9:00 utc
Launch site: Fairbanks, Alaska, US
Balloon launched by: University of California, Berkeley
Balloon manufacturer/size/composition: Zero Pressure Balloon 135.000 ft
Flight identification number: 4
End of flight (L for landing time, W for last contact, otherwise termination time): 10/3/1964