Um,Are you talking about the game creating ships for you?
well nothing will happen until you have Space weapons
After that the more you research a tech branch like Weps,Defense,engines,life support
the more ship designs will pop up
Also researching minaturzation too and some others like medium scale,large scale etc
the more you research say the laser tech branch the smaller the parts thus the more will fit on a hull
I guess this is what your asking