Heavy mount is not something you research, every body have it ... even you
When you design a ship you deside what kind of 'mount' your weapons should use ... a button right top !
The mount avalible is desided by the size of the ship ... once you get there it's easy to understand !
Planetary guns .... well also known as weapon platforms

They are designed like mines, troops, fighters and (drones when we get those)
when placed at a planet they act as defense ... and sometimes a very good one
The size and cargo hold of a planet deside what amount of guns can be present there !
Knowing these two things .. you might even have a chance against the AI
[This message has been edited by SHAnders (edited 10 December 2000).]