There are VERY RARE [as in 'obscenely stupid rare'] situations where there are rogue planets or uncharted comet in the blank hexes. However, a parsec is HUGE and most merchant sensor suites are pretty basic, so the odds of you finding that highly unlikely rogue body are somewhere between zilch, nil, and nada. It's like trying to find something in a pitch black warehouse with a dim chemlite as your only light source. What's more, if your tanks are empty you only hope is look for a rogue body and pray it has something that can be processed into hydrogen on it. A rocky body with no ice on it is just as bad as finding nothing at all. And in the very likely event that you don't find anything, well, you're dead. You can open the hatches and die quick or spend two weeks for your power plant fuel to run out, but either way you're going to die suffocating in the cold.
So what do you do in a situation like that?
- You can go around. Plot a course that'll eventually get you there that isn't in a straight line - if there is one. And there isn't one from Andor or Candory to anywhere.
- You can install cargo tanks. Cargo tanks are temporary fuel tanks that take up cargo space. You jump as far as your drive lets you, transfer fuel from the temporary cargo tanks to the main fuel tanks, and then jump again.
In no case will any amount of fuel propel your ship farther than the drive rating. If you have a ship a J-1 drive, you will have to jump 3 times to cover that distance, which will take up ALL the cargo space on a Type A Free Trader and most of the cargo space on a Type A2 Far Trader. And even then you'll arrive at a system with a Naval Base on it and the Navy has Red Zoned both Andory and Candory, so they're going to inspect your ship from the bolts to the paint job and ask very pointed questions about why you were in a Quarantined system to begin with. If you've got a pass to go to either Red Zone, you're fine. But if you don't things will go poorly for you.