Mission Editor

Hey I've been playing this game on and off for years but I have never been able to get how to properly set up goals in the mission editor. I would set simple things like go here and drop off seals, when they destroy the radar site spawn a ship here, and when you get here the mission ends. But the ship would span before the radar gets destroyed or I would reach the first destination and it would not recognize that I completed the first goal. So whats the trick?