They took one each, and a small supply of fuel.
The fuel supply in the third stage was coming to an end!
Yet by the end of the year the fuel supply was still critical.
Another thing, Nature's fuel supplies will run out one day.
Their fuel supplies are kept low, so they can't reach another system.
Our fuel supplies are too low for us to attempt to find the others.
Those would also need their own separate fuel supply, structure, and systems.
"Then we will either have to stand and fight, or continue running until they exhaust their fuel supply."
The car doesn't carry its own fuel supply, but it's relatively easy to provide one.
It can be difficult to find a secure supply of fuel.