rpg

I have been playing Genesys, and I LOVE it. I'm not playing in a sci-fi setting, but the whole premise behind Genesys is that is is adaptable to any setting, and from what I have seen of the system, it would be great for something like that. There are tons of rules for vehicle stats, combat, etc. and it has guidelines for how to design and balance your own vehicles.

If you are interested in making and playing in your own setting I would definitely recommend Genesys.

If you are wanting something with an existing setting that matches that vibe, then I'd first check and see if some of the community made settings will fit that, and if not, then maybe look elsewhere.

There are a ton of community made resources for Genesys on DriveThruRPG and also in a dropbox maintained by one of the community members, and that dropbox has some resources for an Expanse setting and other sci-fi stuff that would be a good starting point: https://www.dropbox.com/sh/raqr7usuzwizglm/AACMnwsNyT5DPHyjokWZwQLOa/Community%20Content?dl=0&lst=&subfolder_nav_tracking=1

I would also say you should definitely get the core rulebook AND the expanded players guide, as that has tons of good resources and better guidelines for creating vehicles, as well as other useful things. It's really a fantastic GM toolkit.

EDIT: Also regarding the dice, which can be kind of hard to get, they have an app that you can use, as well as charts for converting normal polyhedral dice to the Genesys symbols, and what I personally do is just use the Star Wars dice, which are the same (with slightly different look to the symbols) and are more available, at least where I am.

Rumor has it Firefly was a game of Traveler that was made into a show. Having played traveler, I highly recommend it.

Death in Space is essentially Mörk Borg in space so has enough room for you to decide how hard you like your sci fi

I did something like this with Fate because I had specific ideas about my setting and the aliens, corporations, and organizations I wanted in it. I added some of my own mechanics for ships and stuff, giving them their own attribute tracks and letting players make rolls during space battles based on their position in the crew. It worked well enough for what I wanted, which was more of an action, space opera feel, like Outlaw Star. It won't have a lot rules for all the hard sci-fi stuff you may be looking for if you prefer crunch.

Although recommending a generic system like Fate makes me feel like the kind of guy who suggests GURPs every time a question on a recommended system pops up lol.

I'm surprised no one has mentioned the expanse rpg. Link

I've been enjoying Starforged since it came out. The PDFs are available of course, but it sounds like they're also getting another reprint here in a month or two.

I have not played any of these, so this is less of a reccomendation and more listing things that you can look at, and ask other folks if they agree its better suited for you, but I've heard of a few games that fit some 'extremes' of sci-fi roleplaying

Scum and Villainy probably being the most famous, having a Forged in the Dark style of gameplay where your characters are rogue-ish underdogs, constantly on the run, striving for each job to make them last a few more days

Farflung With a post-scarcity, lighthearted style, where you're travelling, romancing, exploring, creating and living among the stars with your crew

and Impulse Drive for something that's more middle of the road. You have a crew taking jobs and exploring, but they aren't as scrappy and struggling, but also aren't as free and lackadaisical

Stars Without Number is a fun system. Traveller can be a bit complex but the character generation is the best.

Have you looked into Starfinder at all?