Changing control when decoupling

[EthKSP]

When looking at the KSP prebuilt planes I noticed the satellite launcher plane and how when it decouples, you control said satellite until it’s destroyed and then return to controlling the plane, I was how this is done so I could replicate it with my own planes to make some guided missiles 

[Vanamonde]

If you right-click on cockpits and probe cores you can choose "control from here." When the craft parts separate, the player will stay with the chosen part. 

And welcome to the forum.