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 ?
Although the flight was originally scheduled for October 1960 , delays by unplanned preparatory work meant that this was postponed several times , initially to March 6 , 1961 , and finally to May 5.