“The answer to any question starting, "Why don't they—" is almost always, "Money."”
Shooting Destination Moon (1950)
Robert Anson Heinlein was an American science fiction writer. Often called the "dean of science fiction writers", his sometimes controversial works continue to have an influential effect on the genre, and on modern culture more generally.
Heinlein became one of the first American 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 English-language science fiction authors. Among his most notable works are Stranger in a Strange Land, Starship Troopers, which helped create the space marine and mecha archetypes, and the libertarian novel The Moon is a Harsh Mistress.
A writer also of numerous science fiction short stories, Heinlein was one of a group of writers who came to prominence under the editorship of John W. Campbell at his Astounding Science Fiction magazine; however, Heinlein denied that Campbell influenced his writing to any great degree.
Within the framework of his science fiction stories, Heinlein repeatedly addressed certain social themes: the importance of individual liberty and self-reliance, the obligation individuals owe to their societies, the influence of organized religion on culture and government, and the tendency of society to repress nonconformist thought. He also speculated on the influence of space travel on human cultural practices.
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". He also anticipated mechanical computer aided design with "Drafting Dan" and described a modern version of a waterbed in his novel The Door into Summer, though he never patented or built one. In the first chapter of the novel Space Cadet he anticipated the cell-phone, 35 years before Motorola invented the technology. Several of Heinlein's works have been adapted for film and television.

“The answer to any question starting, "Why don't they—" is almost always, "Money."”
Shooting Destination Moon (1950)
Robert A. Heinlein book The Puppet Masters
Source: The Puppet Masters (1951), Chapter 30 (p. 158)
“Never Do Yesterday What Should Be Done Tomorrow.”
Robert A. Heinlein book "—All You Zombies—"
"—All You Zombies—" (1958)
Robert A. Heinlein book Space Cadet
Source: Space Cadet (1948), Chapter 10 “Quis Custodiet Ipsos Custodes?”, p. 126
Robert A. Heinlein book The Number of the Beast
Source: The Number of the Beast (1980), Chapter XIX : Something is gained in translation—, p. 166
Robert A. Heinlein book Beyond This Horizon
Source: Beyond This Horizon (1948; originally serialized in 1942), Chapter 14, “—and beat him when he sneezes”, p. 131
Robert A. Heinlein book I Will Fear No Evil
Source: I Will Fear No Evil (1970), Chapter 25, p. 442
Robert A. Heinlein book The Number of the Beast
Source: The Number of the Beast (1980), Chapter XIX : Something is gained in translation—, p. 166
“The best things in history are accomplished by people who get “tired of being shoved around.””
Robert A. Heinlein book Have Space Suit—Will Travel
Source: Have Space Suit—Will Travel (1958), Chapter 12
“A man who marries at my age isn’t taking a wife, he’s indenturing a nurse.”
Robert A. Heinlein book I Will Fear No Evil
Source: I Will Fear No Evil (1970), Chapter 14, p. 224
Robert A. Heinlein book Methuselah's Children
Methuselah’s Children (p. 606)
Short fiction, The Past Through Tomorrow (1967)
Robert A. Heinlein book Beyond This Horizon
Source: Beyond This Horizon (1948; originally serialized in 1942), Chapter 10, “—the only game in town”, p. 105
Robert A. Heinlein book Rocket Ship Galileo
Source: Rocket Ship Galileo (1947), Chapter 10, “The Method of Science”, p. 108
Robert A. Heinlein book Beyond This Horizon
Source: Beyond This Horizon (1948; originally serialized in 1942), Chapter 13, “No more privacy than a guppy in an aquarium”, p. 126
Robert A. Heinlein book Between Planets
Source: Between Planets (1951), Chapter 7, “The Detour” (p. 83)
Robert A. Heinlein book The Number of the Beast
Source: The Number of the Beast (1980), Chapter XXXVIII : “—under his vine and under his fig tree; and none shall make them afraid—”, p. 371
Robert A. Heinlein book The Rolling Stones
Source: The Rolling Stones (1952), Chapter 4, “Aspects of Domestic Engineering” (pp. 52-53)
Robert A. Heinlein book Sixth Column
Source: Sixth Column (1949; originally serialized in 1941), Chapter 6 (p. 70)
Robert A. Heinlein book Starman Jones
Source: Starman Jones (1953), Chapter 8, “Three Ways to Get Ahead” (p. 82)
Robert A. Heinlein book Beyond This Horizon
Source: Beyond This Horizon (1948; originally serialized in 1942), Chapter 11, “—then a man is something more than his genes!”, p. 111
Robert A. Heinlein book I Will Fear No Evil
Source: I Will Fear No Evil (1970), Chapter 26, p. 459
“Daddy says that, in a dilemma, it is helpful to change any variable, then reexamine the problem.”
Robert A. Heinlein book Have Space Suit—Will Travel
Source: Have Space Suit—Will Travel (1958), Chapter 5
Robert A. Heinlein book Stranger in a Strange Land
"Jubal Harshaw"
Stranger in a Strange Land (1961; 1991)
“I guess I don’t understand women.”
Robert A. Heinlein book Starman Jones
“That’s an understatement.”
Source: Starman Jones (1953), Chapter 19, “A Friend in Need” (p. 211)
“A monarch's neck should always have a noose around it. It keeps him upright.”
Robert A. Heinlein book The Cat Who Walks Through Walls
Richard Ames; chapter 9, p. 108
The Cat Who Walks Through Walls (1985)
Robert A. Heinlein book Red Planet
Source: Red Planet (1949), Chapter 4, “Lowell Academy”, p. 55
Robert A. Heinlein book Space Cadet
Source: Space Cadet (1948), Chapter 9 “Long Haul”, p. 101
““I wish Doc Pickering was here.”
“Yeah, and if fish had feet, they’d be mice.””
Robert A. Heinlein book Space Cadet
Source: Space Cadet (1948), Chapter 14 “The Natives are Friendly...”, p. 160
Robert A. Heinlein book Farmer in the Sky
Source: Farmer in the Sky (1950), Chapter 2, “The Green-Eyed Monster” (p. 21)
“Oh Max, you large lout, you arouse the eternal maternal in me.”
Robert A. Heinlein book Starman Jones
Source: Starman Jones (1953), Chapter 17, “Charity” (p. 185)
Robert A. Heinlein book Starman Jones
Source: Starman Jones (1953), Chapter 9, “Chartman Jones” (p. 95)
Robert A. Heinlein book Have Space Suit—Will Travel
Source: Have Space Suit—Will Travel (1958), Chapter 7
Robert A. Heinlein book Methuselah's Children
Methuselah’s Children (p. 535)
Short fiction, The Past Through Tomorrow (1967)
Robert A. Heinlein book Sixth Column
Source: Sixth Column (1949; originally serialized in 1941), Chapter 9 (p. 113)
Robert A. Heinlein book Farmer in the Sky
Source: Farmer in the Sky (1950), Chapter 4, “Captain DeLongPre” (p. 50)
Robert A. Heinlein book Sixth Column
Source: Sixth Column (1949; originally serialized in 1941), Chapter 6 (p. 72)
Robert A. Heinlein book Starman Jones
Source: Starman Jones (1953), Chapter 19, “A Friend in Need” (p. 211)
“Wherever there is power and mass to manipulate, Man can live.”
Robert A. Heinlein book The Rolling Stones
Source: The Rolling Stones (1952), Chapter 16, “Rock City” (p. 208)
Robert A. Heinlein book I Will Fear No Evil
Source: I Will Fear No Evil (1970), Chapter 12, p. 177
“Pioneers need good neighbors.”
Robert A. Heinlein book Farmer in the Sky
Source: Farmer in the Sky (1950), Chapter 14, “Land of My Own” (p. 147)
Robert A. Heinlein book Between Planets
Source: Between Planets (1951), Chapter 10, “While I Was Musing the Fire Burned” (p. 113)
“Boats and ships are female because they are beautiful, lovable, expensive—and unpredictable.”
Robert A. Heinlein book I Will Fear No Evil
Source: I Will Fear No Evil (1970), Chapter 26, p. 452
Robert A. Heinlein book The Number of the Beast
Source: The Number of the Beast (1980), Chapter XLVIII : L’Envoi or Rev. XXII: 13, p. 508
“Horses can manufacture more horses and that is one trick that tractors have never learned.”
Robert A. Heinlein book Farmer in the Sky
Source: Farmer in the Sky (1950), Chapter 18, “Pioneer Party” (p. 187)
Robert A. Heinlein book Between Planets
Source: Between Planets (1951), Chapter 17, “To Reset the Clock” (p. 176)
Robert A. Heinlein book Between Planets
Source: Between Planets (1951), Chapter 18, “Little David” (p. 182)