In Tom Godwin's short story "The Cold Equations," the moment the reader learns there is a stowaway aboard the Emergency Dispatch Ship and learns all the reasons behind the regulation to jettison stowaways is the moment the reader knows the story can have no other possible outcome: Marilyn must die to ensure the lives of many are saved.
Within the first few paragraphs of the story, the reader learns the law governing the immediate jettison of all stowaways was determined by circumstances, not mankind's choice.
It was a law not of men's choosing but made imperative by the circumstances of the space frontier.
The problem posed by the colonization of outer space is that the colonized planets are so far apart that men's chances of survival on the planets become lower since it is more difficult for the mother planet, Earth, to deliver emergency supplies and assistance. It is too difficult for the "huge hyperspace cruisers" to make emergency stops because doing so is too expensive, and other colonists are already relying on the scheduled stops of the hyperspace cruisers for their own survival. Therefore, emergency ships needed to be designed that could speedily deliver emergency supplies and aid, and in order to be fast, these ships also had to be lightweight. To be lightweight, they could only carry a minimal amount of fuel, carefully calculated based on mass. The additional weight of a stowaway throws off the careful calculation based on mass, ensuring that if the stowaway remains onboard, the emergency ship will run out of fuel and crash, ending the lives of the many the ship was sent out to rescue, as well as the life of the stowaway and pilot.
Hence, the reader can tell after reading the very first page of the story that Marilyn must die, and the fact she is a young, innocent, naive girl cannot save her. The necessity of Marilyn's death is based on the laws of physics and greater need. It's more important for the lives of many be saved rather than the life of one person be spared, especially when both the pilot and the stowaway will inevitably die regardless once the ship runs out of fuel.