S-class freighters actually have nothing to do with the drake equation, but there's a clear pattern to finding them. You'll want to play for at least 3 hours and make 5 warps before capital freighters even start showing up in space battles. The best odds are in pirate systems where you've got a 5% chance, while t3 economies give you 2% and forget about poor systems since they never spawn s-class.

Here's something interesting, you can save before warping and reload if you don't get what you want. The smartest way is checking ship class with your visor right after landing, without talking to any captains first. Pirate systems are definitely your best bet, but be ready to reload quite a few times since it could take anywhere from 15 to 100 tries to get that perfect s-class.

If you're wondering about storage, capital freighters come with 24-34 general slots plus 12-20 tech slots, while regular system freighters are smaller. Good to know that keeping one item in your old freighter inventory helps preserve your base during transfers. You can also find derelict freighters using emergency broadcast receivers or anomaly detectors from asteroid fields if you're looking for something different.