New Interplanetary Drive

With multiple launch windows coming in the near future to Moho, Jool, and Eeloo, I decided to design and build a new Interplanetary Drive capable of pushing or pulling a vessle to any of those destination.  The New Interplanetary Drive (NID) is 5 of the largest 3 meter tanks, which can all be jettisoned as they're emptied, and one half tank, with 4 Aerospike engines.  With docking ports both fore and aft it is capable of fuctioning as a "pusher" or "puller" as the mission design requires, and this design also allows for additional fuel to be docked if required.