Your ship won't get destroyed. If there is space combat, space combat will work like regular combat. You explode and die, you respawn. When you land on a planet, your ship will be out of reach from enemies, very static like. It will be a hub for fast travel, I would think. It won't be on an enemies radar, because you won't be able to use it on the planet. This isn't to say that perhaps there won't be a specific mission that involves your ship breaking down and you having to go look for parts to fix it. As always: Take what I'm saying as PURE speculation. I have NO information to back this up except my vision and expectations for the game.