Has anyone been able to get past this mission (Training Area B)? I destroyed all the targets, including the flying target and the 2 silos, but for some reason the mission never completes. The timer just goes down to zero and you have to start over. Is there something else that needs to be done to trigger a mission complete?

Update:
I figured it out. One has to destroy the towers on the water even though the reticle is pointing toward the cave.