Twenty years ago today Sputnik I was blasted into space and sent back the first hesitant bleeps which opened an era.
In two decades, man has girdled the earth, conquered the moon, and penetrated deeper and deeper into space. The triumphs and tragedies of this spectacular era are recalled by the BBC's Science Correspondent, James Wilkin son, who also looks into the future - at the new worlds yet to be conquered.
A Radio News production