Humans look at the night sky. And when we do, we dream of traveling through space. To distant stars, to other planets. Space exploration is a grand and noble dream that adults never seem to grow out of. We're all still, deep down, that little kid who wanted to be an astronaut.
Just what is a generation ship anyway?
A generation ship, sometimes called a world ship, is a hypothetical manned interstellar spacecraft traveling at sub-light-speed to a destination so far away that it must be crewed by multiple generations on its journey. A perennial sci-fi subgenre for novels and short stories, it first appeared in Aladra Septama's 1930 short story Tani of Ekkis in Amazing Stories Quarterly. But, like all good science fiction, the idea was first discussed in nonfiction papers among the scientific community of rocket pioneers, astronaut theorists and philosophers. Essays like Robert H. Goddard's 1918 The Ultimate Migration imagined the death of our Sun and humanity's theoretical survival in "suspended animation" on an "interstellar ark." Konstantin Tsiolkovsky's 1928 essay The Future of Earth and Mankind first described multiple generations of passengers on a fueled space colony that he called "Noah's Ark."
Flights of imagination like these linger in science fiction and scientific theory today. Most early imaginings hinge on the death of our Sun, which will happen in about ten billion years, and humanity's need to find another star in order to survive. More recent stories invoke the climate crisis as a possible cause for the inhabitability of Earth well before our Sun red-giants.
The setting
The unequivocally joy of science fiction is asking questions and dreaming up possible answers. The best science fiction is aware of and understands the science of both this world and the world of the story – the actually possible science as opposed to the invented fiction. Otherwise, what you're writing is fantasy. Your readers want to explore the questions you posit, too. Like "Why would interstellar travel be necessary?" or "What is the state of Earth and our solar system when we launch a generation ship?" or "What technology allows for a generation ship to work?" In science fiction, these are all elements of your worldbuilding. Some of the elements might be McGuffins–imagined solutions that let you move the plot forward–but your world must have a logic to it that leans on familiarity of our own world. What are the systems on the ship that sustain life? The oxygen, water, toxicity filtration, food? In what ways would a contemporary reader recognize these systems? And in what ways would they find them delightfully strange?
Strangeness is a matter of perception. World elements strange to a reader would likely not be strange to the characters on the ship. Indeed, for the world to feel lived in, the characters must have a sense of normalcy about the ship, their entire world. Until, that is, they discover strangeness that jars against their own perception of normality and familiarity. What are the mysteries of the ship? This is part of the world you are building, too. Remember that as familiar as we are with our world, there are large parts of it that are entirely inexplicable to many of us. How can that familiar feeling manifest in your strange new setting?
And because your setting is a constructed machine, you get to explore some unique ideas about it as setting: where in the journey is the story taking place? Is this the first generation on the ship, or the last, or somewhere in the middle? Is the setting behaving as it should or is the machine breaking down? Or evolving? What kind of resources are required to sustain the ship?
As mind-boggling weird science writer Jeff VanderMeer noted in his craft book Wonderbook, The places and spaces in which a story occurs are not inert or merely backdrops to action–they have energy, motion, meaning, and create certain effects depending on your approach…Landscape not invested with emotion or point of view is lifeless.
The people
A generation ship is a setting unlike most in that it is a relatively contained environment, and it has a very specific purpose. That is a boon when we come to think about the characters inhabiting the ship as they too have a very specific purpose imposed upon them. Do they accept that role or balk against it? What is the weight of their daily existence in this constructed place? How do they treat others? And, of course, because where there are people there is culture, in what way is the character privileged?
The generation ship offers up some unique questions when it comes to people. Such as who designed and built it? What did/do they believe the ship will accomplish? Are they onboard now? Did they triumph at their success, or where they like Oppenheimer who was devastated to have invented the atomic bomb?
How many people does your generation ship carry? In New Scientist magazine, anthropologist John Moore argued that the magic number for a generation ship is 160 people. Others say 5,000. What do you say? The more people, obviously, the more complex your social systems and power structures are likely to be. Is every person on your ship crew? Or are there passengers as well? Does your ship carry every living human, or was there a selection process? Who was selected, and who got to decide? All of these questions are intricately entwined with the setting of the generation ship, how it looks, how big it is, how it functions. And, of course, its purpose.
Social structures, politics, and power dynamics
Let's look at the purpose of your generation ship in a cultural context. In most cases, the purpose of a generation ship is to colonize another planet. Often, a life-supporting, habitable "goldilocks" planet–not too hot, not too cold, but just right–has been identified as humanity's last hope for survival. Colonization and occupation was a dominant world-view for many centuries, but has recently been reframed as an aggressive act of cultural violence, and the concept of "empty land" completely disavowed. Colonization for the exploitation of resources, like mining, is also a much favored trope in generation ships stories and is inherently tied to Western capitalism. So, in this modern context, is the purpose of your generation ship colonization of an "empty" planet? For adventure, exploration, resources? Or are your generation shippers the last human survivors? Are they more like asylum seekers or refugees than colonists? How does the story of your generation ship reflect and reinforce or question our existing social, political and economic structures?
Cultural structures, too–is your generation ship a ship of Earth, or the ship of one nation or culture? And how did this come to be? Does the society on your ship enforce class lines? Is it a utopic or dystopic society? Who has power and who wants it? Does leisure exist? Is there a religion on your ship, or multiple?
On a generation ship, the primary social unit is likely to be a family. How do families work on your ship? Are they genetic or found? What about extended family? Does childhood exist? How controlled are families and reproduction rates? Or do they not exist at all and reproduction and social units are completely revolutionized? Who can and can't have children?
The world of a generation ship is a microcosm that you get to design in its entirety. What world will you build? All this world building, all the choices you make on the page, will lead you to the central conflict of the story. There are many possibilities in such a fragile constructed environment in the vastness of space–social revolution, increased infertility rates, ship failure, a new mission–and the ultimate question of whether the ship succeeds or not. Regardless of the success of the ship, the success of your story will hinge on how completely you have built the world, and populated it with people the reader can care about.
As you embark on your generation ship story, I will leave you with one final thought about the ethics of generation ships. The first generation on such a ship would likely have signed up to be aboard–volunteered, selected, or otherwise, are just the last few left. The point is that they may have had some choice. But a generation ship relies on the idea that children will be born on the ship and ultimately take over as the next crew when their parents die. Those children have not chosen this project, and likely won't be able to choose or change their role on the ship. How can a mission be singularly focused on for multiple generations and thousands of years? And should it be?