Sputnik program

Unmanned space missions launched by the Soviet Union in the late 1950s to demonstrate the viability of artificial satellites.

Sputnik I was launched October 4, 1957. See that page for mission details.

[Sputnik II]? was launched some months later, and carried the first living passenger, a dog named Laika the Russian Space Bitch. The mission planners did not provide for the safe return of the spacecraft or its passenger, making Laika the first known space casualty.

(Unsure whether there were more Sputnik launches.)