Robert Anson Heinlein (1907 –1988) was an American science-fiction author, aeronautical engineer, and Naval officer. Sometimes called the “dean of science fiction writers”, he was among the first to emphasize scientific accuracy in his fiction, and was thus a pioneer of the subgenre of hard science fiction. His published works, both fiction and non-fiction, express admiration for competence and emphasize the value of critical thinking. His work continues to have an influence on the science-fiction genre, and on modern culture more generally.
-Wikipedia