4. Arthur C. Clarke
Sir Arthur Charles Clarke was an English writer known for the 2001: A Space Odyssey (1968) and other sci-fi works. Clarke seems to have an optimistic view of human exploration and expansion in the Solar System.
Another concept he used that an intelligent species, including human, will evolve into something closer to gods, such as depicted in the Rendezvous with Rama. He also predicted the use of geostationary satellites in 1945, a decade before first man-made object orbited the Earth.