AKA Gravity Tractors
Image from Alex Mulvey
|A common configuration for a gravity tug system uses two or more massive craft in orbit around a point forward of the asteroid itself. As the tugs exert thrust they drag the asteroid behind them, using the asteroid's own gravity
Image from Steve Bowers
|Sometimes it is necessary to move the asteroids in Barnard's Belt. Here a pair of gravity tugs arranged in tandem are gently pulling this colonised rock to a new orbit. This variant of the gravity tug concept utilises asteroid material gathered from the asteroid itself to increase the mass of the tugs, making the process more efficient.