Last night I watched Space Race, the series created by Deborah Cadbury. This episode was all about Sputnik 1 and Explorer 1, and their creators, von Braun and Korolev. Naturally, as a fan of Vanguard, I was disappointed at how the Naval Research Laboratory's satellite was treated in the documentary. There was no mention of the International Geophysical Year, or coherent explanation of the rationale behind preferring a non-military launch vehicle. The documentary maintained that James van Allen was called in at the last minute to build instrumentation for Explorer's experiments. The reality is that van Allen designed his experiment for Vanguard, but cunningly made it compatible with both satellites; when it became clear that Vanguard was under a cloud he transferred to Explorer. When Vanguard 1 was launched, it flew without its experiment packages.
Nonetheless, Vanguard 1 is still up there, and Explorer 1 re-entered in less than a month. Green and Lomask, historians of Vanguard, point out that its technologies are the basis of the USA space industry today.