Others
I have listed a few other people that you may be interested to research
Deceased
Konstantin Tsiolkovsky 1857 – 19 September 1935
Robert H Goddard 1882 - 1945
Wernher von Braun 1912 - 1977
Carl Sagan 1934 -1996
Gerard K. O'Neill - O'Neil Cylinders
Space writers
Robert Heinlein 1907 - 1988
Isaac Asimov 1920 - 1992
Arthur C Clarke 1917 - 2008
Alive
Keith Hanson and Carolyn Meinel - L5 Society
Robert Zubrin - Mars society
Also
See Entrepreneurs