Sputnik program

Sputnik (Спутник), a Russian word meaning "satellite" or literally "fellow traveler", is a name applied to certain spacecraft launched under the Soviet space program. "Sputnik 1", "Sputnik 2" and "Sputnik 3" were the official Soviet names of those objects, while the remaining designations in the series ("Sputnik 4" and so on) were not official names, but were names applied in the West, to objects whose original Soviet names may not have been known at the time.

Being the Russian term for "satellite", the word Sputnik has appeared in the names of other spacecraft:

These objects are listed with their official Soviet names:

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