ABSTRACT
The year 1957 marked a new era for the physics of electromagnetism in space. With the launch of the first unmanned satellite, Sputnik, by the USSR on October 4, 1957, space became accessible to intelligent beings. The United States followed four months later with the launch of Explorer I on January 31, 1958. Before the spacecraft era, electrodynamic phenomena in space were studied primarily by remote means. Spacecraft made possible in situ physical measurements in distant regions previously not accessible. This led to important discoveries that clarified and revolutionized our thinking about space.
