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 ?
They beat the U.S. for the first man in space , by launching cosmonaut Yuri Gagarin into a single Earth orbit aboard Vostok 1 in April 1961 , one month before Shepard 's flight .