>Yet we've managed to do it relatively reliably.

Sure. Do that when you're in the middle of an ocean that's a few trillion miles wide. It's not as if you can just dive down to the bottom of the ocean there, mine some bauxite, take it back up to your sinking ship, refine it, manufacture new repair materials for the boat, then repair it, is it?

No, you have to have it shipped from a coast a trillion miles away. So again, where are they manufactured, and how long do they take to get there? Can any of this shit even be made in the vicinity of Venus, where transit times might be non-absurd? There are no recoverable materials on the planet itself, are there?