Like most Heinlein novels, it's very much hard science fiction: all of the math checks out.
Provides examples of:
- And the Adventure Continues: After travelling to Mars, and eventually the Asteroid Belt, the family shrug and keep on Rolling.
- Asteroid Miners: The titular family Stone travels to the Asteroid Belt, where the twins of the family hope to sell food and luxury items to the miners extracting radioactive ores.
- Asteroid Thicket: Averted. The book takes care to note that the asteroids are far enough apart that the risk of being hit by one is infinitesimally small. Nevertheless The Rolling Stone takes precautions anyway when they enter an unusually dense field that's a haven for miners.
- Captain Space, Defender of Earth!: Roger Stone and, later, Grandma Hazel help support the family by writing a deliberately over-the-top three-vee serial in the Captain Space Defender mold.
- Cliffhanger Copout: Appears in-universe in a Story Within a Story,The Scourge of the Spaceways. John Sterling ends one season in an unsurvivable Death Trap. He starts the next season out of the Death Trap and, hero that he is, is too modest to tell people how he managed to escape. Then the next adventure starts.
- Comedic Sociopathy: Played with when Buster is suffering from severe space sickness. The twins note that it would be better if the Stone (illegally) corrects their orbit to return to Luna, noting that if their brother died "It would spoil the whole trip."
- Conveniently Unverifiable Cover Story: When her grandsons need an attorney on Mars, Hazel claims to be entitled to practice law — something her family had never heard before. When had she been admitted to the bar?Hazel: Years and years ago, back in Idaho — before you were born. I just never got around to mentioning it.
Roger: Hazel, it occurs to me that the records in Idaho are conveniently far away.
Hazel: None of your sass, boy. Anyway, the courthouse burned down.
Roger: I thought as much.
- Cool Old Lady: Hazel Stone (Cas and Pol's grandmother) serves at the Rolling Stone's chief engineer. She once made her way dealing blackjack and is one of Luna's founding fathers.
- Creator Backlash: In-universe for poor heroic John Sterling, star of The Scourge of the Spaceways.Roger: I've hated that mealy-mouthed Galahad since the moment I created him.
- Cryptic Background Reference: On Mars, Hazel Stone recognizes someone from decades back who was involved in the Lunar revolution. Heinlein's novel The Moon Is a Harsh Mistress later features Hazel as a young girl in the revolution.
- Don't Make Me Take My Belt Off!: Roger Stone talks to the twins after Hazel and Buster are rescued, telling them the history of the belt in his hands, and how his whole family was raised on it. He seems to be threatening them with it for their screwup, but then notes that they're too old for it to do any good, and they're going to have to live with the consequences of their actions like adults, instead of just being punished and getting over it.
- Expospeak Gag: Hazel tries to pull this along with a big helping of Sesquipedalian Loquaciousness to explain to Captain Vandenberg why they got a flat cat for Buster, trying to satisfy his need to see the intelligent Martian natives. The boy sees right through it.
- I'm a Doctor, Not a Placeholder: Quite possibly the Ur Example.Edith Stone: I'm a doctor, not a fortune-teller.
- Introduced Species Calamity: Long before The Trouble With Tribbles was even thought of, the Flat Cats end up kicking off a massive case of overpopulation aboard the ship, aided by the lack of predators and environmental threats.
- I Take Offense to That Last One: Used when Castor plays a trick on Pollux and sends him flying away from the ship, refusing to pull in his line.Pol: Pull me in, you red-headed moron!Cas: Don't call me "red-headed!"
- Kill 'Em All: Hazel's solution for freeing Roger from his scripting contract. It doesn't take...
- Manchild: Roger has shades of this, mostly related to the War God incident, fighting temptation to lie to Edith to keep her from going to the plague-infested ship, and most egregiously when he condemns the War God's passengers to several more weeks of quarantine after they land, because he just had go aboard to see her after their extended separation.
- Market-Based Title: After the rock band hit the big time, later UK editions were retitled Space Family Stone.
- Money, Dear Boy: The reason Hazel ends up continuing the serial anyway. It does help pay for the Stone's modifications, admittedly.
- Most Writers Are Writers: As is a common theme in Heinlein's work, Hazel and Roger both have careers as fiction writers.
- My Beloved Smother: Roger gets constant flack from Hazel who insults him and then calls him a sissy when he refuses to rise to the bait.Cas to Pol: "Have you ever noticed how Dad gets pushed around until he gets his own way?"
- Noodle Incident: After Cas and Pol are arrested on Mars for tax evasion, their father notes that at least it wasn't for experimenting with atomics inside city limits - this time.
- Ridiculously Cute Critter: Martian flat cats, which may have inspired Tribbles.
- Rocket Ride: Rocket-powered rideable craft much like broomsticks are used in asteroid mining.
- Setting Update: Invoked in-universe when Roger Stone accuses his mother of using recycled plots. She cheerful admits it and states that in the next episode, "I'm going to equip Hamlet with atomic propulsion."
- Sci-Fi Writers Have No Sense of Scale: Averted in the book proper of course. In Hazel's serial she cheerfully makes Science whimper loudly and hide its head in the very first episode she writes.Roger: For starters, spaceships do not make 180 degree turns!Hazel: This one does.
- Screw the Rules, I'm Doing What's Right!: Early in their trip to Mars, Buster, the youngest of the Stones, suffers from severe space sickness. Roger makes plans to swing their ship back towards Luna, despite being turned down by traffic control and knowing he'd at minimum be heavily fined, and have his ship master's license revoked.
- Shown Their Work: In the book Expanded Universe, Mr. Heinlein explains how Mrs. Heinlein and he spent many hours calculating the precise orbit of the spaceship when it departs Luna and slingshots around Earth toward Mars. They had to do it with paper and pen, because in the early 1950s there was no other way and he wanted it to be correct.
- Science Marches On: It's a case of not thinking of it, because the basic physics remained unchanged. But it appears to never have occurred to Heinlein that Jupiter could be used to boost a spacecraft to reach a further target faster and with less fuel required. (This book ends with the Stones heading for Saturn.)
- Silk Hiding Steel: Edith Stone is outwardly the quiet, solid center of family with seemingly no strong opinions and who seems to have given up on her career as a doctor when she married. On the other hand Cas and Pol note that no family argument is decided until she weighs in, and she politely but firmly ignores her husband Roger's objections when she volunteers to transfer to a ship that is suffering from a viral plague that has already killed their ship's surgeon.
- Take That!: You have to wonder if some of Roger Stone's rantings about his much-hated science-fiction show contract had anything to do with Heinlein's experiences working on Destination Moon, or Tom Corbett Space Cadet.
- Theme Twin Naming: Castor and Pollux are of course named after the twins of Greek Mythology.
- Twin Banter: Castor, 20 minutes older than his brother, often calls Pollux "Junior", while Pollux calls Castor "Grandpa". They insult, prank, and mock fight each other regularly enough that they have a ritual ("Even-Steven!") for formally calling a truce. They also routinely alternate lines when talking to anyone else, and are basically inseparable.
- Twin Switch: Pulled by the twins when Pollux attended the same math class in school twice. Castor paid the price later when he had to catch up on his studies.
- What Would X Do?: Played for drama when Hazel becomes lost in space due to a faulty scooter and they have to work out what her actions would be in response to know where to search for her.
- Yes-Man: 50% of Edith Stone's dialog consists of "Yes, dear" in response to Roger Stone's rantings. When she does speak up it's serious business.
- You Are Grounded!: Roger Stone confines Cas and Pol to quarters after they almost kill Hazel and Buster by not logging a malfunction in the family rocket scooter. In typical fashion they break it to save the day.