Portal:Spaceflight/On This Day/4 October

• 1957 - The Soviet Union launches Earth's first artificial satellite, Sputnik 1 atop a Sputnik-PS rocket, triggering the Space Race.
• 1959 - A Luna launches the Luna 3 probe.
• 1960 - A Thor-Ablestar launches the Courier 1B satellite.
• 1964 - A Delta C launches the Explorer 21 spacecraft.
• 1965 - A Molniya launches the Luna 7 spacecraft.
• 1972 - A Voskhod launches the Kosmos 522 satellite.
• 1976 - A Soyuz-U fails to launch an unknown satellite.
• 1978 - A Kosmos-3M launches eight Strela satellites.
• 1984 - A Molniya-M launches the Kosmos 1604 satellite.
• 1990 - Launch Complex 45/2 at Baikonur is demolished by an exploding Zenit-2 rocket, during a failed attempt to launch a Tselina satellite.
• 1991 - A Soyuz-U launches a Foton satellite.
• 2012 - A Delta IV launches the GPS IIF-3 satellite.