From Writer's Almanac:"It's the birthday of Robert Heinlein, born in Butler, Missouri (1907). He wrote more than 50 novels and many collections of short stories. Heinlein is best known for his novel Stranger in a Strange Land, about a boy born during the first manned mission to Mars.
He called his books 'speculative fiction' rather than 'science fiction.' He was trying to write about events that could actually happen, taking into consideration the natural laws of the universe."