...and decelerators
This mod for the Kerbal Space Program 1 aims to provide mass driver parts (gigantic coil and rail guns) and control aids that can propel engineless unmanned cargo vessels with high acceleration to effectively perform precise orbital maneuvers with enough dV to go from, say, LKO to the Mun.
With the help of mods like MechJeb and TCA it should be possible to organize a network of accelerators and decelerators for moving cargo around the system cheaply and easily.