In response to repeated rocket attacks from the Palestinian territory of Gaza over the past few years, Israel has deployed a missile defence system called Iron Dome.

What is it?

Iron Dome is a missile-defense system developed by Rafael Advanced Defense Systems Ltd., an Israeli military contractor, in conjunction with the Israeli Defense Forces (IDF). It is designed to intercept incoming rockets, long-range artillery and aircraft, and destroy them in the air before they reach populated areas.

An Iron Dome missile fired to intercept a rocket fired from the Gaza Strip explodes over the border in southern Israel on Nov. 17, 2012. Debris from the blast can be seen to the right of the dark smoke cloud. (Ariel Schalit/AP)

In 2007, then-Israeli defense minister Amir Peretz announced that Iron Dome was the government’s choice for dealing with the threat from short-range missiles. Iron Dome was first deployed in March 2011 to thwart missiles being launched into Israel by Hamas militants in Gaza.

According to Israeli officials, Iron Dome has had a 90 per cent success rate in destroying Hamas rockets fired into populated areas.

There are a number of different Iron Dome installations. Most of them are located in southern Israeli towns such as Siderot and Ashdod, which are well within range of Hamas’s Grad rockets, although there is also an installation in the country’s commercial capital, Tel Aviv.

How does it work?

Iron Dome has three components: the detection and radar installation, battle management and weapons control (BMC), and the missile firing unit itself.

The Iron Dome defense system fires to intercept incoming missiles from Gaza in the Israeli port town of Ashdod on Nov. 15, 2012. The system can fire clusters of missiles simultaneously to intercept multiple incoming targets. (Tsafrir Abayov/AP)

The radar system detects opposing missiles or artillery shells when they are launched.

The BMC is the brain of the system. It calculates the trajectory of the rocket and where it is expected to hit. The BMC is capable of tracking and firing at multiple targets simultaneously.

If an incoming rocket is headed to a low-risk area, like an empty field, Iron Dome will leave it alone. But if a rocket is on a path to a sensitive target, like a populated area, Iron Dome launches a Tamir missile that can intercept and destroy it.

The system also figures out the best place to intercept the incoming target along its trajectory, to try and avoid debris falling on populated areas.

Incoming targets travel extremely fast, and the trajectory calculations and decision to launch are done within seconds.

The Tamir interceptor missiles cost about $40,000 US each, and can be fired day or night and in any type of weather. They are guided for the first part of their flight by the radar system and BMC on the ground, which keeps them on course.

When the Tamir nears its target, the missile's own onboard radar takes over to take it as close as possible to the incoming rocket or shell. The warhead it carries explodes, destroying both the Tamir and the incoming target.

The Iron Dome installations can be moved by a truck if necessary, and typically have a radar unit controlling three launchers. Fully loaded, each launcher contains 20 missiles.

The launchers can be grouped together, or spread out to cover a larger area. Iron Dome installations are usually configured with a coverage radius of about 70 kilometres.