It is difficult to say what is impossible, for the dream of yesterday is the hope of today and the reality of tomorrow.

• Robert H. Goddard

Robert H. Goddard

U.S. professor and scientist, was a pioneer of controlled, liquid-fueled rocket. He launched the world’s first liquid-fueled rocket on March 16, 1926. From 1930 to 1935 he launched rockets that attained speeds of up to 885 km/h (550 mph).