Robert A. Heinlein (July 7, 1907 - May 8, 1988) was one of the most influential and controversial authors of "hard" science fiction. He set a high standard for science and engineering plausibility that few have equaled, but also helped to raise the genre's standards of literary quality. He was the first writer to break into mainstream general magazines such as The Saturday Evening Post in the late 1940s with unvarnished science fiction. He was among the first authors of bestselling novel-length science fiction in the modern mass-market era. For many years Heinlein, Isaac Asimov, and Arthur C. Clarke were known as the "Big Three" of science fiction.
The major themes of Heinlein's work were social: radical individualism, libertarianism, solipsism, religion, the relationship between physical and emotional love, and speculation about unorthodox family relationships. His iconoclastic approach to these themes has led to wildly divergent perceptions of his works. His 1959 novel Starship Troopers was excoriated by some as being fascist. His 1961 novel Stranger in a Strange Land, on the other hand, put him in the unexpected role of pied piper to the sexual revolution and counterculture.
The English language has absorbed several words from his fiction, including "grok," meaning "to understand something so thoroughly that it becomes part of the observer." During his lifetime, beginning with his very first works in the later 1930s, he was also a major influence on many other writers, who tried to emulate, with varying degrees of success, the apparently effortless skill with which he blended speculative concepts and fast-paced storytelling.
Heinlein won four Hugo Awards for his novels, awarded following the year of publication. In addition, fifty years after publication, three of Heinlein's works were awarded "Retro Hugos" - awards given retrospectively for years in which no Hugos had been awarded. He also won the first Grand Master Award given by the Science Fiction Writers of America for lifetime achievement.