1962-10-03 USA Explorer 14

An Explorer 14 launch cover from "Sarzin", postmarked at Cape Canaveral with a hand cancel on October 3, 1962.

Explorer 14, launched on October 3, 1962, was an early NASA scientific satellite that advanced understanding of Earth's radiation belts and space environment. Its instruments included a cosmic ray detector, an ion electron detector, a solar cell measurer, a proton analyzer, and a trapped particle radiation experiment. The spacecraft also featured an experiment to measure how radiation affected solar power cells, and its own solar cells were protected by a 60mm glass cover.

Understanding the radiation environment around Earth was particularly important as NASA moved toward increasingly ambitious crewed missions. Its measurements helped scientists understand the radiation environment that spacecraft and astronauts would encounter beyond the lower atmosphere.

(Reference from Discovering the Cosmos with Small Spacecraft: The American Explorer Program By Brian Harvey)