Bruce Murray Space Image Library
Original AP caption: "This photo released by TASS in April 1961 shows cosmonaut Maj. Yuri Gagarin during training. It was the Soviet Union's own giant leap for mankind -- one that would spur a humiliated America to race for the moon. It happened on Tuesday, April 12, 1961 when the air force pilot became the first human in space. (AP Photo/TASS) AP1963"