Lines of defence: how the US anti-missile system works

Satellite detects launch

Warhead

Kill vehicle

Intercontinental

ballistic missile

Multi-stage

booster

1

2

3

Radar tracks flight

1st line of defence

Patriot and THAAD interceptors launch from South Korea

 

2nd line of defence

Aegis ballistic missile interceptors fire from warships in the Pacific

 

3rd line of defence

Interceptors fire from Alaska and California. Kill vehicle tracks incoming warhead and alters course to collide at 15,000mph

Warhead

Kill vehicle

Satellite detects launch

Intercontinental

ballistic missile

Multi-stage

booster

Ground- and sea-based radars track missile’s flight

1st line of defence

Patriot and THAAD interceptors launch from South Korea

2nd line of defence

Aegis ballistic missile interceptors fire from warships in the Pacific

3rd line of defence

Interceptors fire from Alaska and California. Kill vehicle tracks incoming warhead and alters course to collide at 15,000mph