Counting rates from the two discrimination levels of this detector yielded information on directional fluxes of electrons with energies above 0.5 MeV. One detector was oriented perpendicular to the spacecraft spin axis and had a 16° full-angle aperture. There was a two-level pulse-height discriminator associated with each detector. The UCSD Particle Experiment consisted of two plastic scintillator detectors. Experiments Directional and Omnidirectional Energetic Protons and Electrons The spin axis pointed at right ascension 80.97° and declination 20.9°. The spin rate ranged from 72.9 to 73.2 rpm during the life of the spacecraft. During launch the spacecraft failed to despin. A digital solar aspect sensor measured the spin period and phase, digitized to 0.041 seconds, and the angle between the spin axis and the Sun direction to about 3° intervals. One analog channel was subcommutated in a pattern 16 frames long and was used to telemeter spacecraft temperatures, power system voltages, electric currents, etc. During ground processing of the telemetered data, the analog information was digitized with an accuracy of 1/100 of full scale. Half of the channels were used to convey eight-level digital information, and the others were used for analog information. The time required to sample the 16 channels (one frame period) was 0.323 seconds. A 16-channel PFM/PM time-division multiplexed telemeter was used. The instrumentation included three sets of particle detectors to study both electrons and protons, and a two-axis fluxgate magnetometers to determine magnetic aspect. The backup payload for Explorer 14 was modified and used for Explorer 15. 3.4 Proton-Electron Scintillation DetectorĮxplorer 15 was a spin-stabilized, solar cell-powered spacecraft instrumented to study the artificial radiation belt produced by the Starfish high-altitude nuclear burst of July 1962.3.2 Electron and Proton Solid-State Detectors.3.1 Directional and Omnidirectional Energetic Protons and Electrons.Directional and Omnidirectional Energetic Protons and ElectronsĮlectron and Proton Solid-State Detectors

Xyplorer 15