Explorer 1

Overview

The first satellite launched by the United States, in 1958, whose radiation detector discovered the Van Allen radiation belts. Built by JPL and launched by the U.S. Army — NASA did not yet exist.

Related

Knowledge connections

• OrbitLow Earth Orbit (LEO)
• Associated withSputnik 1

Sources

Facts on this topic will be cited from these primary and reference sources.

• NASANational Aeronautics and Space Administration

  Mission data, planetary science, space telescopes, and public-domain imagery.

  Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.