I’ve come across several references recently to refuelling satellites using a gas station in orbit.
Today’s invention is a somewhat simpler approach than NASA are envisaging.
Given that liquid in microgravity forms a sphere, by the action of surface tension, I would release giant blobs of liquid fuel from a series of spacecraft.
Satellites in need of a fill-up would approach such a sphere at low relative velocity, open a port at the front, fly gently through (having first extinguished all potential sources of ignition) and emerge refilled on the far side. They would then be able to alter their course and speed again by firing rockets powered by this liquid propellent.
Such globes of fuel could also be used as a way to help de-orbit ailing satellites by the slowing effects of fluid drag.