Necessity is the mother of invention, and the need for us humans to clean up our skies of all the objects we have sent into space is of a real necessity. As far as my wee little mind can comprehend, a tug is vehicle that transports another it its destination; navigating through treacherous waters, although these tugs play multiple roles, it seems that one role is really trash collection. Old objects are gathered and sent to Earth's incinerator, cleaning up the upper layers of Earth, so we can put up more of our trash. The other role is the ability to ferry newly formed objects to Luna to support the development of human colonization. These tug boats could facilitate the construction of larger Space Ports and ship yards for R&D for interplanetary space travel. I am a civilian with no scientific credentials in an ocean full of Scientists. I hope that my utterings do not offend anyone in anyway.