"The Cold Equations" is a Novelette by Tom Godwin, first published in Astounding Science Fiction in 1954, which has been done as a radio play for the X Minus One radio drama of the 1950s, an episode of The Twilight Zone (1985), and a 1996 made-for-TV movie for the Sci Fi Channel.
Barton, the pilot of an Emergency Dispatch Ship (EDS) dropped from a Hyperspace cruiser, discovers there's a stowaway on board, a young girl named Marilyn. His ship is taking a load of vaccines to the planet Woden, it has just enough fuel to make the deceleration and landing with no reserve, and if they don't get there, 8 colonists will die. Also, there is no way to reduce the weight of the ship to compensate for Marilyn's mass. Typical practice as required by regulations is to jettison stowaways, as these vessels do not have any reserve fuel to allow a safe landing with the extra weight. However, the situation is complicated because Marilyn is an innocent who just wanted to see her brother (who is stationed on Woden) and didn't know that stowing away on an EDS would carry a penalty worse than a stiff fine.
The primary ship informs Barton there is no way the primary ship can retrieve Marilyn (other lives depend on their strict timetable as well), that there's no other ships in the area, and he knows there's no planetary launch available, either. He must reduce the ship's mass, but he lacks the appropriate means to, for example, seriously strip the ship of unnecessary components. (There's nothing on the ship that isn't necessary.) She can't land the ship either as it's not computer-piloted, so Barton can't sacrifice himself. Barton doesn't like the only choice available, and realizes that he's going to have to live with the thought of what he's going to have to do for the rest of his life.
Failing to reduce the ship's mass — by spacing Marilyn — will mean the ship will crash, and Barton, Marilyn and the colonists will die. Marilyn eventually accepts that there is no alternative, so after being able to reach her brother over the radio to say goodbye, Marilyn walks into the airlock, and Barton ejects her into space.
The point of the story is that in space, sometimes the cold equations leave no alternative, and balancing the equation means someone dies.
This story provides examples of:
- Always Save the Girl: The whole point of the story is to avert this trope. Marilyn can't be saved and attempting something risky when much more is at stake than just her is irresponsible and irrational.
- Anthropic Principle: The premise of "The Cold Equations" is that a character finds himself in a situation where he has no choice but to Shoot the Dog. Thus, a requirement of the story is that it is set up such that there is no Third Option.
- Big Brother Worship: Marilyn's motive. She has a big brother who works out on the frontier, she only sees him once every few years, and so she saves up money and sneaks aboard a ship she thinks is on its way to where he is. The irony is that even if the Cold Equation hadn't been in play, the shuttle was on its way to a different group.
- Cold Equation: This is the Trope Namer: the ship can handle X weight and has Y fuel and no amount of technobabble or heroic spirit is going to balance the equation when Marilyn is added in.
- Deconstruction: Of a type of Invincible Science Hero common in literature of the day. He'd get himself in trouble, then Techno Babble up a Deus ex Machina solution to the problem. Barton, placed in a similar scenario, tries his utmost to science up an answer, but the simple fact is the numbers don't work out that way. Marilyn has to die, and there's nothing he can do about it. Unsurprisingly, The Cold Equations ended up contributing to the death of the archetype it subverted.
- Downer Ending: There's no solution to the problem that does not result in Marilyn having to be executed.
- Emotions vs. Stoicism: Explored. On Earth people have achieved sedentary comfort and can afford to indulge tawdry displays of emotion like Missing White Woman Syndrome. But out in the frontier where mankind is still exploring and conditions are much more hostile, only those who are or achieve the mindset of The Stoic survive long and those who make a living out on the frontier accept that there are certain... well, cold equations that cannot be bent or exempted because of sentiment. The reactions of Marilyn's family nicely highlight this: her parents, being from Earth, are predicted to hate Barton and not understand why he killed their daughter, while Marilyn's brother Gerry is reached and, despite his horror, understands at once that Marilyn is doomed and that no one can save her.
- Face Death with Dignity: Marilyn is able to achieve this and by the end walks calmly into the airlock, having accepted her fate.
- Genius Thriller: Played with. Barton does everything he can to try to figure out how to save Marilyn with the resources he has on hand, but unfortunately the science facts are completely against him.
- I Did What I Had to Do: Throwing the girl out the airlock is necessary to get the vaccines to the colony. Barton doesn't want to do it but there is no other way.
- Informed Attribute: Many of the issues raised on the "Headscratchers" page boil down to the fact that the ship is stated to be a bare-bones emergency delivery vehicle, but has many features (an airlock, a closet big enough for a stowaway to hide in, a cabin big enough to walk around in) that simply don't square with that label.
- Kill the Cutie: Marilyn is killed by necessity.
- Men Are the Expendable Gender: A secondary theme of the story. Barton is fully prepared to jettison the stowaway before he realizes it's a girl, and he spends a fair bit of time afterward angsting about what he will have to do solely because of Marilyn's gender. He states flat-out that he would have no issue with jettisoning a male, regardless of their age or reasons or the promise they had ahead of them, but because Marilyn is not of the expendable gender he does everything in his power to spare her, and when he realizes he can't, treats her graciously (gives her time to prepare, connects her with her brother so they can say goodbye) in a manner he certainly wouldn't have treated a male.
- Missing White Woman Syndrome: Barton notes that "On Earth [Marilyn's] plight would have filled the newscasts... Everyone, everywhere, would have known of Marilyn Lee Cross and no effort would have been spared to save her life." In space, however, there's no room for that kind of emotion.
- Mohs Scale of Science Fiction Hardness: Very Hard (with the exception of hyperspace aircraft carriers), as the fuel dilemma is based around the application of the Rocket Equation, which can be simplified to: In space, you need fuel to lift the fuel, and more fuel to lift that fuel, so every gram counts.
- My Greatest Failure: It is implied at the end that Barton will be forever haunted by the events of this story.
- No OSHA Compliance:
- While the Rocket Equation does limit the amount of fuel to be used in the shuttle, the idea that a futuristic space shuttle would have fewer fail-safes or backups than a 20th century airplane (modern aircraft are always given a large enough fuel supply that, even if there's a delay due to weather or problems at the landing site, they can typically circle the runway for several minutes, or possibly even hours, regardless of the distance of the trip) is more than a little strange. Either the OSHA does not exist in the future, or someone decided that a shuttle that can literally hold only one person and a small amount of cargo, and just barely enough fuel to get them from point A to point B, is a good idea, something that in the 20th and 21st century would never leave the design phase. note
- It's mentioned that the flight in question is an emergency flight being conducted at the absolute outer limit of the spacecraft's fuel range, with very little margin for error. Of course, this still doesn't excuse the total lack of a preflight inspection (as even the most cursory one would still have found the girl before takeoff), so OSHA still has lots of citations to hand out here. note
- Science Hero: A deliberate aversion — no-one pulls a technological Ass Pull to save the girl.
- Settling the Frontier: Gerry Cross and the other colonists Barton is on his way to do are doing this, and in keeping with the trope's description, the dangers colonists face out on the frontier are fierce.
- Shoot the Dog: Either Barton spaces Marilyn, or she dies anyway, along with him and six other people. He spaces her.
- Swiss Cheese Security: The whole situation could have been avoided by a 30-second pre-launch check. Or, you know, maybe a lock on the door?
- Take a Third Option: The fact that there isn't one is the entire point. The story was written to be a subversion of early 1950s Science Fiction and its omnipotent men of SCIENCE! optimism.
- Thrown Out the Airlock: The only option in the end is to space Marilyn.
- Too Dumb to Live: Subverted. Marilyn appears to be this for stowing away aboard a shuttle where all stowaways are as a mandatory rule spaced, but apparently civilians aren't made aware of this rule and the only caution she is given is a big KEEP OUT sign. Spelling out for civilians why they are to keep out probably would have saved Marilyn's life.
- Too Good for This Sinful Earth: Every quality about Marilyn and every word she speaks is meant to evoke reader sympathy for her. She didn't sneak aboard the shuttle for nefarious reasons, she just wanted to see her brother. She's not a spoiled rich girl who thinks she can buy her way out of trouble, she's a hardworking girl from a poor family who saved up because she thought she would just get in trouble and have a fine to pay. She even offers to work and cook for her upkeep.