On May 5 , 1961 which astronaut became the first American in space aboard " Freedom 7 " , launched by a Redstone booster on a 15 - minute ballistic ( suborbital ) flight ?
The first human spaceflight took place on 12 April 1961 , when cosmonaut Yuri Gagarin made one orbit around the Earth aboard the Vostok 1 spacecraft , launched by the Soviet space program .