I've created a level 2 missile silo (capacity for 20 missiles) and I've built 20 anti-ballistic missiles. Yet when I click on the missile silo, it reports 0/20 missiles (empty). What must I do to actually get my missiles loaded into the silo??

I´m not sure,  but there are some missiles you can built in the shipyard...maybe those are what you are looking for. They are called "nuclear missiles". Hope it helps./


...(Edit)
Found itttt\\/ It´s in the defense tab and you have interplanetary missiles, and also Anti-ballistic ones.

After seeing in the popup help for the silo that it can fire either nuclear missiles or anti-ballistic missiles, I first got the silo to level 2 (permits 20 missiles), then built 20 anti-ballistic missiles in the shipyard. Yet I'm baffled over how to get those missiles to show up in the silo. I have a silo, I have missiles, yet the missiles aren't in the silo .

All missiles can be seen in the Imperium. 
You can only control Interplanetary missiles (IPM's), and this is done from the 'Galaxy' page. You cannot manually fire Anti Ballistic Missiles, they are automatic. You will only have an option for missile attack when you build IPM's, as in the pics below. You can see your IPM missile count when you click the Missile Attack icon.
You will also be given an option as to which defensive structures you want to target (as only defensive structures can be attacked with IPM's)
 

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