Howto expand the unit
Components and other units can be attached to the initial unit
To attach a component you need to build a socket, tunnel pair
Main > Unit > Mods > Attach
Left,Right,Up,Down keys to navigate
Right or Enter key to execute command
To add another unit you first need to attach an adapter.
The type of adapter selects what unit that can be attached next.
standard, fortress, recon, death star