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.
Sputnik 1, the first artificial satellite to go into orbit, launched 4 October 1957
Sputnik 2, the first spacecraft to carry a living animal (the dog Laika) into orbit, launched 3 November 1957
Sputnik 3, a research satellite launched 15 May 1958
Being the Russian term for "satellite", the word Sputnik has appeared in the names of other spacecraft:
Dnepropetrovsk Sputnik, a series of scientific and technology development satellites
Istrebitel Sputnik, "Fighter Satellite", a series of antisatellite weapons and targets
Tyazhely Sputnik, "Heavy Satellite", a failed Venus probe
Upravlyaemy Sputnik, "Controllable Satellite", a series of ocean surveillance and missile detection satellites
US-A, nuclear-powered ocean radar surveillance satellites
US-K, molniya orbit missile detection satellites
US-KS, geosynchronous orbit missile detection satellites
US-KMO, Modernised geosynchronous orbit missile detection satellites
US-P, electronic ocean surveillance satellites
US-PM, modernised electronic ocean surveillance satellites
These objects are listed with their official Soviet names:
Sputnik 4 – Korabl-Sputnik 1
Sputnik 5 – Korabl-Sputnik 2
Sputnik 6 – Korabl-Sputnik 3
Sputnik 7 – Tyazhely Sputnik
Sputnik 8 – Venera 1
Sputnik 9 – Korabl-Sputnik 4
Sputnik 10 – Korabl-Sputnik 5
Sputnik 11 – Kosmos 1
Sputnik 12 – Kosmos 2
Sputnik 13 – Kosmos 3
Sputnik 14 – Kosmos 4
Sputnik 15 – Kosmos 5
Sputnik 16 – Kosmos 6
Sputnik 17 – Kosmos 7
Sputnik 18 – Kosmos 8
Sputnik 19 – Venera 2MV-1 No.1
Sputnik 20 – Venera 2MV-1 No.2
Sputnik 21 – Venera 2MV-2 No.1
Sputnik 22 – Mars 2MV-4 No.1
Sputnik 23 – Mars 1
Sputnik 24 – Mars 2MV-3 No.1
Sputnik 25 – Luna E-6 No.2
Sputnik 40
Sputnik 41
Sputnik 99
