Timeline of Solar System Exploration - 1950s

1950s

1957

• Sputnik 1 – 4 October 1957 – First Earth orbiter
• Sputnik 2 – 3 November 1957 – Earth orbiter, first animal in orbit, a dog named Laika

1958

• Explorer 1 – 1 February 1958 – Earth orbiter; first American orbiter, discovered Van Allen radiation belts
• Vanguard 1 – 17 March 1958 – Earth orbiter; oldest spacecraft still in Earth orbit

1959

• Luna 1 – 2 January 1959 – First lunar flyby (attempted lunar impact?)
• Pioneer 4 – 3 March 1959 – Lunar flyby
• Luna 2 – 12 September 1959 – First lunar impact
• Luna 3 – 4 October 1959 – Lunar flyby; First images of far side of Moon