Ty Franck spent years building a fictional solar system in his spare time. He'd sketch out asteroid mining colonies, water-ice hauling routes between Saturn's moons, the slow politics of people who lived their whole lives in tin cans floating through nothing. It was a tabletop RPG setting, the kind of obsessive worldbuilding that happens in notebooks nobody else reads. Franck happened to be working as George R.R. Martin's personal assistant at the time, which is how he met Daniel Abraham, an established fantasy novelist who was friends with Martin. Abraham looked at what Franck had built and saw a novel in it.
They started writing together under the pen name James S.A. Corey. The first book, Leviathan Wakes, came out in 2011. It became the foundation of The Expanse, nine novels, an Amazon adaptation, the gold standard for modern space opera. But the thing that made it work wasn't the alien protomolecule or the ring gates. It was the fact that Franck had designed his universe around shipping routes and water rights. The solar system in The Expanse feels like a place where people go to work.
That detail tells you almost everything you need to know about how to write space opera.
The genre has a reputation for being about scale. Galactic empires, fleets of warships, civilizations spanning thousands of star systems. But the writers who've figured out how to make space opera resonate aren't the ones building the biggest universes. They're the ones finding the smallest human problems inside those universes and letting the scale press down on them like gravity.
Make the Galaxy a Place People Live
The Expanse works because its solar system has an economy. Earth has a universal basic income and too many people. Mars is a military-industrial society focused on terraforming. The Belt survives by mining and shipping resources that the inner planets need. Every conflict in the series grows from those material conditions. When Belters get angry, it's because Earth controls their air supply.
Franck built all of this for his tabletop game, which meant it had to be specific enough for players to make decisions inside. You can't run a tabletop session where someone says "I want to buy supplies" and the GM has no idea what supplies cost or who controls the market. That granularity carried over into the novels. When a character on Ceres Station talks about the price of water, you believe them, because the authors have actually thought about where that water comes from and how far it traveled.
Most space opera writing guides will tell you to build your world. What Corey figured out is that you need to build your world's economy. Who produces what. Who needs it. Who controls the routes between producer and consumer. Once you have that, your plot will start generating itself.
The Empire Inside Your Character
Arkady Martine is a Byzantine historian. Before the novels took off, her day job involved studying how the Eastern Roman Empire actually operated, how it absorbed neighboring cultures, how it made people want to be absorbed. She brought that expertise into A Memory Called Empire with a precision that most science fiction writers can't fake.
Her protagonist, Mahit Dzmare, is an ambassador from a tiny independent space station called Lsel. She's sent to the capital of the Teixcalaanli Empire, a civilization so culturally dominant that Mahit has spent her whole life studying its poetry and falling in love with its language. The tension isn't military. Nobody's shooting at anybody for most of the book. The tension is that Mahit genuinely admires the culture that's trying to swallow her home. She thinks in Teixcalaanli metaphors. She dreams in their literary forms. And she knows that if the empire absorbs Lsel Station, everything she loves about her own people will be smoothed away into a provincial footnote.
I'm not sure why this works as well as it does, but I think it's because Martine never stops to explain what imperialism feels like in the abstract. She just shows you Mahit reaching for a Teixcalaanli poem when she needs comfort instead of reaching for anything from home. One sentence in a 400-page novel, and it communicates more about cultural assimilation than any amount of exposition could.
If you're writing space opera with empires, that's the lesson. Put a character inside the empire's gravity and show how their thinking changes.