Science: Explorer IV

Explorer IV sped into space with a double task firmly impressed on its electronic senses. It must report on the belt of radiation, probably particles from the sun, that was found by Explorer III about 600 miles above the earth's surface. And it must tell U.S. scientists more than they yet know about cosmic rays.

Little is known about the radiation belt. Explorer III, with a single Geiger counter, reported only that the radiation was strong enough to jam the counter's tube. The more sophisticated instruments of Explorer IV, two Geiger counters and two scintillation counters, are designed to measure the radiation...

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