Milkrun

Milkrun: noun, spacer slang for a highly profitable, but tedious, trade route. Also; milking: verb, doing a milkrun repeatedly.

For example, in FE2 and FFE, the route Sol - Barnard's Star is the mother of all milkruns. It is very short distance, it is absolutely safe, and guarantees a good profit for every trip. You don't need any weapons or equipment other than Autopilot. Doing this route will put a spacer in the position to buy any ship they want within a matter of months.