need a little tech tree/starbase help

[xierxior]

so here I am minding my own buisness in my little corner of the universe when a fleet of ships appears in my system next to the worm hole!
they sort of sat there for a couple turns but then they decided it would be a good idea to start taking my planets away from me
I just BARELY killed them off and I want to build a starbase ontop of the worm hole so enamy fleets cant invade my system as easily.
I did some looking around on the forums and it appears you can research a mobile constrution platform? what do you have to research to get this thing? and if you build a starbase out in space does it need ordinance storage?

I was thinking about stuffing abounch of shield generators and torpedos on it so if it gets pounded on a little bit I won't have to worry about repairing the thing all the time would this work?