Each of these sources can be mined on planets and moons. There are four sources of fuel within Starbound: Uranium, Solarium, Plutonium, and Liquid Echirus, which replaced Coal as a fuel source a while back.
Travelling within a star system is free, but travelling between these systems will cost fuel proportional to the distance traveled, with a 500 max cost.
Starbound is all about surviving as you travel across the galaxy, and to do that, you’re going to need plenty of fuel for your ship.
