I don't get the space tug idea. A space tug requires four trips: 1 - from the space gas station to the satellite. 2 - tows satellite back to space gas station. 3 - tows satellite back to original orbit. 4 - returns to space gas station. It may make more sense for the space tug to be a space tanker. Two trips, and one would be heavy with fuel, the other would be light.
I don't get the space tug idea. A space tug requires four trips: 1 - from the space gas station to the satellite. 2 - tows satellite back to space gas station. 3 - tows satellite back to original orbit. 4 - returns to space gas station. It may make more sense for the space tug to be a space tanker. Two trips, and one would be heavy with fuel, the other would be light.