Note: I am still somewhere around the early parts of the game, having befriended several of the alien species. I am unsure about any details of the victory condition (and in fact don't even know if there is one), and have only vague ideas about the overarching mysteries of the game. I would greatly appreciate hiding any spoilers from myself or others who are interested.
I am curious about whether it is possible to beat the game without visiting the human outpost altogether? AFAIK, it would be possible to get enough fuel from the Melnorme traders to last a long while if the player knew what they were doing.
If that is not possible, is it possible to avoid getting the radioactives from the Sol system? Let's say that the player's lander is destroyed on Mercury while having all the radioactives onboard, and they accidentally shoot any others they come across in the system. Is continuing from this point possible? What if the player has only a single unit of fuel?
These questions assume that the player will win all fights with the accompanying Earthling Cruiser, without any losses. However, not with the flagship (without great improvements).