Planet location does affect parts availability. This happened to me on my last completed contract - after I won my base attack, I sat on the planet for another two months waiting for incoming parts and fixing/salvaging everything I'd recovered on a 100% salvage contract. If you're on a backwater, there's a good chance that NOTHING will be obtainable. The only way to get what you need then would be to move to another planet (like Galatea) on your own dime, since you'd probably be deadheading (moving without a contract, so no employer paying for it) or go raiding, basically putting yourself in pirate shoes.
