How do ICBM early warning systems differentiate between a real threat and a launch of a normal rocket intended to go to space?

Question

How do ICBM early warning systems differentiate between a real threat and a launch of a normal rocket intended to go to space?

In: 2759

Answer 1

Both ICBM and normal rocket launches only take a few minutes. After the rocket has used up all its fuel it is easy to see where it will go. Early warning systems simply wait for the rocket to stop burning, and then check if the rocket will hit the country or stay in orbit.