Unmanned
Unmanned - Space probes are a form of robotic spacecraft.
Robotic spacecraft
Sputnik
yes
Unmanned
Unmanned - Space probes are a form of robotic spacecraft.
Robotic spacecraft
it has to have had no humans
Finding ways to power the spacecraft or probe is one problem of unmanned spaceflight. Unmanned spacecraft have limited abilities and they don't have the ability to do follow up testing.
Sputnik
Humans, no. Unmanned spacecraft, yes.
The Mariner 1 spacecraft was unmanned spacecraft to fly to mars
it is cheap and no risk of life to persnnel
Viking I
yes
It was the Russian spacecraft, a unmanned one called Luna 2.