The only way to "trade" ships is by boarding them. SM in a boarding ship, SM in a boarding party, load it, move the ship to wherever it needs to be, set the target ships speed to 1 so your boarders don't all die, board the ship, click until the crew is dead, and voila! You now have a ship that traded hands from one empire to another. It still has a hole in it's armor and a 1-month abandon-overhaul modifier tho.
Trading components via drops and invasions of uninhabited rocks is also something that works.
I'm getting a little frustrated as I can't seem to find a way to build surface to orbit weapons. I go to the build ground unit section, select static, and it just isn't there.
I thought I had the prerequisites, but I must be missing something.
What is it?
I seem to remember that until you have a suitable weapon (not the tech) researched (such as a laser) you cannot build any STO.
Thanks for trying to help, I seem to have developed that - I tried both gauss and lasers, but no luck. .
What else could it be?
Do you have the other techs that go into a functional weapons, beam fire controls, active sensors and reactors?
Otherwise, just to be sure, you go to the unit class design tab, hit static (only static), hit STO-Weapon, and then select something from the list that should populate.