The terminal high-altitude area defence (Thaad) system is transportable and rapidly deployable, designed to intercept ballistic missiles inside or outside the atmosphere during the final phase of flight. It is one of the last lines of defence against the asymmetric ballistic missile threat - low-tech weaponry used by rogue states - and uses hit-to-kill technology to destroy an incoming target.
The 900 kilogram Thaad missile has a range of 200 kilometres. That makes it difficult for enemy missiles to launch decoys and countermeasures to fool it and its high-altitude intercept mitigates effects of weapons of mass destruction before they reach the ground.
It is capable of detecting threats at a range of 1,000km. Once an incoming missile has been detected, the interceptor is launched and guided to the target. Once in proximity, the interceptor's main booster burns out and it separates. An infrared seeker helps it to close in on the target. The effect, at a speed of 2.8km per second, causes the complete destruction of the enemy warhead including any nuclear, chemical or biological agents.
The Patriot advanced capability-3 (Pac-3) is a surface-to-air guided missile air defence system, also designed to destroy missiles by colliding with them. The missile is almost 6 metres long, weighs 700kg, and can engage targets at altitudes of 24,000 metres and ranges of 20km.
The Pac-3's high maneouverability is thanks to 180 tiny rocket motors that finely adjust the missile's trajectory.
Once its ground control has brought the Pac-3 close to the target, an active radar seeker in the nose locks it on to the warhead of the inbound ballistic missile. Then a small explosive warhead launches a blast of low-speed steel fragments, increasing the probability of destruction as it slams home at a velocity of up to five times the speed of sound. Lockheed Martin, Vought Systems and Raytheon are the prime contractors.
The Aegis combat system is a highly integrated radar and missile system, capable of simultaneous warfare in the air, on the surface and underwater. The computer-based command-and-decision element is the core of the Aegis system, with its AN/SPY-1 radar, known as "the shield of the fleet", capable of performing search, tracking and missile guidance against more than 100 targets at a range of more than 190km.
It controls a Phalanx close-in weapon system (a rotary cannon firing almost 3,000 rounds per minute) and the Mark 41 vertical launch system, which deploys the US navy's family of standard surface-to-air missiles.
The Aegis system is being enhanced to act in a theatre missile defence role, to counter short and medium-range ballistic missiles of the type employed by rogue states.
The Eaps (extended area protection and survivability) interceptor weighs only 3kg and is less than 1 metre long, yet the miniature hit-to-kill interceptor is capable of destroying small, close-in targets from tactical rockets, artillery shells and even mortar rounds at ranges down to a few kilometres.
Each missile costs US$16,000 (Dh58,769) and in designing it, Lockheed Martin pulled together technologies from the medical imaging and mobile-phone industries to produce a guidance seeker capable of achieving the high accuracy needed to intercept a rocket or mortar round in flight at close range.