Research Continues Six Decades After Launch Of Explorer 1
Tick, tick, tick. The device — a Geiger counter strapped to a miniature tape recorder — was registering radiation levels a thousand times greater than anyone expected. As the instrument moved higher, more than 900 miles above the surface, the counts ceased. Scientists were baffled. It was early 1958, the United States had just launched its first spacecraft, and a new discipline of physics was about to be born.