TenForward: Where Every Vulcan Knows Your Name

I would like to see more settings with beam-powered propulsion. That's honestly the most realistic way of actually achieving interstellar travel. You set up large beaming arrays powered by fusion reactors or huge solar arrays. Or you build a laser system right out of the Sun's upper atmosphere. Then you accelerate to significant fractions of c, riding on a beam of laser light.

Slowing down is a problem, but even that can be done with beam power. As it approaches a destination system, a ship can unfurl a secondary mirror array. If the system back at Sol can maintain focus over that distance, you use the secondary array to bounce light back onto the incoming craft, slowing it down. And if you can't maintain focus over that distance, you can use chained pushing lasers powered by the destination Sun to send a slow down array ahead of your incoming crewed starship. Then you just have pushing lasers installed in both systems, and you can easily send ships back and forth.

If we end up ever actually doing interstellar travel for real, it's likely to be through this method. Laser light sails are the cheat code for practical interstellar travel, but they almost never show up in fiction. Which is a shame, as there's a lot of interesting settings and themes that could be explored. If you're riding on a beam ship, you don't actually have engines onboard capable of speeding up or braking your ship. You surely have some engines - to avoid space debris and for navigating before/after being accelerated/decelerated by the laser arrays. But you are ultimately completely at the mercy of the people operating those beaming arrays. If you're relying on a braking array to slow your ship down at its destination, what happens if the destination system decides you're no longer welcome there? By simply not turning on the laser, you will be doomed to scream off into the void. And speeding up/slowing down is just such an intricate dance of light and momentum. Lasers have to be aimed at not where your ship is, but where it's going to be. And a chain of many stations may need to work together, each in their turn, for the journey to succeed. And who is paying for all this infrastructure? Who controls it? Is it nation states, unified world government, is it private corporations? Is travel on them free, or do you have to pay a lifetimes of wages to afford a ride on a beam ship? Lots of possibilities. Oh, and since ships travel along known paths, space piracy is a real possibility in the right setting.