[Interest Check, maybe] High stakes space drama

Loads and loads. vagueGM just mentioned a bunch, and if you really want *tactical* PbtA then Flying Circus could be adapted. And there are probably lessons in Root. (These are both very complex PbtA games.)

Fate games can be played on maps / boards, btw -- just with zones instead of range bands or grids. Tachyon Squadron, which is indeed something you need to buy to read, pulls most of its pretty damned cool dogfighting system from the RPG Warbirds.

My question might have been a bit off-topic. I'm not actually looking for a tactical game. It was just that PbtA was mentioned and I got curious what PbtA systems can support a space opera game. Thanks for the recommendations.

Meanwhile I've been tinkering with my own system a bit and I figured a decent way to simulate orbits and distances.

The orbital elevation is divided into several specific layers, let's say layers 1, 2, 3, 4, and 5 for Earth. Each orbit has a perigee and an apogee and, consequently two phases, each phase takes the number of turns equal to its elevation. Orbital phases switch immediately whenever you make a burn to change Perigee Elevation (P-El) or Apogee Elevation (A-El).

Let's say you start the combat in a circular orbit at P-El 1 and A-El 1. It is currently your Perigee Phase and you use a Prograde Burn action and some fuel to move your A-El to 5. Now for 5 turns your elevation will be 5, then for 1 turn it will be 1, then it will be 5 for five turns again and so on. You get a Molniya orbit.

At this point, whenever you are in the Apogee Phase of your orbit, you can use another Prograde Burn action and spend more fuel to move your P-El higher. Let's say to P-El 3. And immediately after that burn, you switch to your Perigee Phase. Now you will spend 3 turns in perigee phase at P-El 3 and then have 5 more turns in your Apogee Phase at A-El 5.

The higher the elevation is, the less fuel you spend on maneuvers, and it gets easier to detect and fire at targets. Orbital movement also affects distances.

Different phases = +1 distance.
Current elevation difference ±1 = +1 distance.
Current elevation difference ±2 or more = +2 distance.

Each weapon has different delays at different distances. That is the number of turns it takes for the projectile to reach the target. Even light has a speed limit, so distances matter.

I'll have to playtest it at some point.

That sounds like Phoenix Command in space.

Okay. Should I consider you among the willing test subjects future playtesters then?

Ah, Phoenix Command...

Hmm. For starters, I didn't use DC checks. At all. There are… some… tables. Only 4 ship components to be damaged. A couple of stats that shouldn't drop to zero. And that's about it. I'm thinking of capturing an average PbtA and/or Lancer player, exposing them to the rules, and studying their reaction. If it will be mortal terror, I'll probably rewrite it or drop the idea entirely. What I suspect would actually happen, though, is people who expected mechanical complexity will find too little of it and will be disappointed; and people who instead didn't want any complexity will get spooked by that picture and won't even try reading the system. That's okay.

To be clear, the above image is a joking portrayal of all the complexity in one of the most tactically detailed RPGs of all time. And I don't think your system sounds like Phoenix Command, S.F. Smells more like Traveller to me, or even GURPS Space or Jovian Chronicles.

When ai was reading about the phases and the orbits, that's what made me wonder if it was going beyond Traveller level combat and going into something else, it might not be, but I don't have the world's most experience with the Traveller Starship combat, so I don't really recall how complex it it. iirc, it does take into effect gravitational situations around orbits, but I don't recall how specific it was about orbit it was and the maneuvering and so on. Also, big ships vs. small ships.

As a player, personally, while I like options, and to control my fate, uh, Phoenix Command is one of those where I wish it were a button I could just press (I own all of Phoenix Command, too, just because (also I'm a collector of the grotesque)...it's one of those things I kind of want to do myself one of those days), so I don't think complexity is something most people will be seeking, even in some sort of starfighter campaign. Mortal terror is something to beware of, but if something like PbtA is your guideline, that should be manageable.

Even Traveller can scare people off, and with what I had mentioned, I don't blame them. Some people want something that has some basic tactical arrangement like that chessboard you've brought up, but less pieces and Traveller uses a lot of settings and pieces and moving parts.

That's how it felt to me when I was writing it. Not being a huge GURPS fan myself I then tried to move the system away from GURPS as much as possible. I'm not sure if I completely succeeded in that, considering that most simulation systems tend to gravitate towards something GURPS when simulation is the only thing the developer thinks about. Anyway, the goal was to also make it simple enough to be fun, so I ended up with something closer to a collectible card game, except you have your full deck in your hand.

The rules are currently in alpha stage. I will be adding "action cards" next and will probably want actual players' input on that one.
Actually this rules fragment above is the most complex thing I have in the system, and it also replaces a map. So if Traveller has anything more complex than that at any point, then Traveller will be more complex in total. Besides, this system is intended to be "rules-lite-ish", which I presume Traveller isn't.