Robert Anson Heinlein (July 7, 1907 – May 8, 1988) was an American science-fiction writer. Often called the "dean of science fiction writers", his controversial works continue to have an influential effect on the genre.
Heinlein became one of the first science-fiction writers to break into mainstream magazines such as The Saturday Evening Post in the late 1940s. He was one of the best-selling science-fiction novelists for many decades, and he, Isaac Asimov, and Arthur C. Clarke are often considered the "Big Three" of science fiction authors.
Heinlein was named the first Science Fiction Writers Grand Master in 1974. He won Hugo Awards for four of his novels; in addition, fifty years after publication, five of his works were awarded "Retro Hugos"—awards given retrospectively for works that were published before the Hugo Awards came into existence. In his fiction, Heinlein coined terms that have become part of the English language, including "grok", "waldo", and "speculative fiction", as well as popularizing existing terms like "TANSTAAFL", "pay it forward", and "space marine".