This document outlines major milestones in human space exploration from the early rocket experiments of Robert Goddard in the 1920s to the ongoing International Space Station, including the first satellites launched by the Soviet Union and United States in the 1950s, the first human spaceflights by Yuri Gagarin and Alan Shepard in 1961, the Apollo moon landings culminating with Neil Armstrong's first steps on the moon in 1969, and the space shuttle program with both successful missions and tragic accidents like Challenger and Columbia.