Four (Cadmium sulfide) CdS-type particle detectors were used for this purpose, one at a pitch angle of 90°, one at 125° and two at 160° (one with and one without a magnetic deflection within the entrance aperture).

Orientation was referred to the direction of the local magnetic field line such that 0° corresponded to a detector looking downward towards the Earth in the northern hemisphere.

[3] This experiment was designed to measure the net down-flux of particles from the trapping region and the intensities of geomagnetically trapped particles at low altitudes, over a wide range of latitudes and longitudes and a long period of time, and to study the long-term decay of electrons in the artificially produced "Starfish Prime" radiation belt.

Orientation was referred to the direction of the local magnetic field line such that 0° corresponded to a detector looking downward towards the Earth in the northern hemisphere.

[4] This experiment was designed to measure the directional fluxes of electrons (E>5 keV) mirroring at satellite altitudes and being precipitated into the Earth's upper atmosphere.

An apparent intermittent failure in the detector power supply decreased further observations to only brief periods throughout the active life of the satellite.

Orientation was referred to the direction of the local magnetic field line such that 0° corresponded to a detector looking downward towards the Earth in the Northern Hemisphere.

[5] This experiment was designed to detect protons and alpha particles in the outer zone and in solar cosmic-ray events at low altitudes and high latitudes.