Twinfinite: "Out of the myriad challenges you’ll face in Bethesda Game Studios’ space-faring adventure, inventory management is one of the more time-consuming endeavours. After all, while your pockets are deep and there’s room aboard your spaceship to store items, there’s only a finite amount of space to work with. Luckily, a small detail that may’ve flown under many players’ radars is the fact that you can access an unlimited storage cache to stockpile important loot."
It's the safe in your room the chick takes you to in the Lodge after you get in.
Problem is, that safe is not linked to when you want to sell stuff or use resources to create weapon mods etc
It’s good to hold armor sets, weapons and decorations you want to hold onto until you can get more storage. Don’t use it for resources because it’s not linked to you or your ship when selling or crafting