What is Israel's Iron Dome defence system used against Iran's drone and missile strikes and how does it work?

Israel faced a fierce bombardment of over 300 drones and ballistic missiles over Saturday night, in the latest challenge to the country's '90 per cent effective' rocket-intercepting Iron Dome.

All but a few were intercepted by Israel and its allies, including the UK and the United States, officials said. 

The powerful short-range defence system was used to shoot down the incoming barrage of drones, cruise missiles and rockets fired from Iran, Lebanon, Iraq and Yemen, and has also been working in full-force to handle attacks throughout the six-month war against Hamas.

The Iron Dome works to detect incoming rockets, before determining its path and intercepting them, and has blasted thousands of airborne weapons since it first went into operation in 2011. 

The three-part, multi-billion pound air defence system, developed by Israel with US backing after the 2006 Lebanon War, has been crucial in defending Israeli cities for over a decade and is credited with preventing serious damage or casualties.

MailOnline has looked into the impressive system and how it works.

What is the Iron Dome?

The Iron Dome is an all-weather mobile system in Israel that is made up of at least 10 missile-defence batteries strategically distributed around the country.

The device is made up of three main sections: a radar detection system, a computer to calculate the incoming rocket's trajectory, and a launcher that fires interceptors if the rocket is deemed likely to hit a built-up or strategic area.

It uses a sophisticated radar to detect incoming airborne objects such as a drones, rockets, and missiles, it sends the information back to a command-and-control centre.

Here, the threat is tracked to assess whether it is a false alarm and the potential destination of the flying object.Each truck-towed unit then fires radar-guided missiles to blow up short-range threats like rockets, mortars and drones in mid-air.

The system fires the interceptors - just 6 inches wide and 10 feet long- at the incoming threats that seem most likely to hit an inhabited area.

Each Iron Dome battery consists of three to four launchers that can each carry up to 20 Tamir interceptor missiles.

The batteries can neutralise threats launched from up to 43 miles away, while at the same time ignoring projectiles that are projected to strike unpopulated areas.

In late 2012 Israel said that it hoped to increase the range of Iron Dome's interceptions, from a maximum of 43 to 155 miles away and make it more versatile so that it could intercept rockets coming from two directions simultaneously. 

The 10 Iron Domes placed throughout the country are able to defend up to nearly 60 square miles of land - protecting countless civilians and critical infrastructure.

The system was developed by state-owned Rafael Advanced Defense Systems and Israel Aerospace Industries and was upgraded in 2012, but the details of the changes were not made public.

The United States backed the initial project with a $200,000 grant in 2006.

The Iron Dome is just one of Israel's three-tiered missile defence system along with the The Arrow, and David's Sling. 

The Arrow system developed with the US is designed to intercept long-range missiles, including the types of ballistic missiles Iran said it launched on Saturday.

The Arrow, which operates outside the atmosphere, has been used in the current war to intercept long-range missiles launched by Houthi militants in Yemen.

David's Sling, also developed with the US, is meant to intercept medium-range missiles, such as those possessed by Hezbollah in Lebanon.

How effective is the Iron Dome?

Iron Dome's effectiveness has improved since it first successfully took out a hostile projective in April 2011, and has gone on to achieve a reported success rate of around 90 per cent, according to Rafael Advanced Defence Systems.

In Saturday night's attack, most of the around-300 missiles were intercepted by the defensive weapon before reaching Israeli territory, while others were shot down by the United States and other allies.

 It has also been proven to be highly effective in recent years, with its abilities especially highlighted in 2021 after militant groups in Gaza fired at least 4,000 rockets during the 11-day May war.

In the first 24 hours of the conflict 470 rockets were fired with Iron Dome system intercepting about 90% of the rockets heading to populated areas within Israel.

In the US, Lt. Gen. Henry A. Obering wrote in Defence News: 'Iron Dome has stopped over 2,000 rockets fired at Israeli population centres with a remarkable success rate, an achievement that also shifted US thinking about homeland missile defence.

'Iron Dome is the most proven and affordable option against very short-range fire.'

He hailed it as a 'gamechanger'.

On the battlefield during Operation Pillar of Defence in November 2012, and when used in Operation Protective Edge in 2014, the system had 84 per cent and 91 per cent rates of success, respectively.

 But things become more complicated if the drones are flying so low that the radar can't detect them.

Israel has hundreds of interceptor missiles at its disposal, but the Iron Dome has come under immense pressures as seen on October 7, when Hamas attacked Israel with a barrage of thousands of missiles.

Hamas said it launched 5,000 rockets in the initial attack and Israel's military countered by saying just 2,500 rockets were fired. 

'That quantity was simply too much for Iron Dome to manage,' said the Modern War Institute report. 

This suggests the Iron Dome has a limit to the number of rockets it is able to intercept, and if that number is exceeded, the rest of the rockets will permeate the system, according to a Forbes report from 2021.

Just two days after the October 7 massacre, the Israeli government asked the US to provide more precision-guided munitions for its combat aircraft and more interceptors for its Iron Dome missile defense system, according to a US official.

How much does it cost?

A complete battery costs an estimated £80million to produce, while each interceptor costs up to around £40,000 to launch, according to the Institute for National Security Studies, a Tel Aviv think tank.

The US has invested heavily in the system, helping with development costs and replenishing it during times of conflict.

Since 1946, the US has allocated almost nine billion pounds to Israeli missile defense systems, including nearly two billion pounds for the Iron Dome, according to the Congressional Research Service. 

US President Joe Biden has said he will ask Congress for £11.4billion in military aid for Israel - which would help with air and missile defence systems such as the Iron Dome, according to the White House.

'We're surging additional military assistance, including ammunition and interceptors to replenish Iron Dome,' Biden said. 

The future of the Iron Dome

Rafael says it delivered two Iron Dome batteries to the US Army in 2020 - but the US is not the only country keen to get its hands on the powerful batteries.

Last year, Ukraine asked Israel for an Iron Dome system and other air defence equipment to defend against Iranian ballistic missiles and attack drones used by Russia in its ongoing invasion.

Israeli Prime Minister Benjamin Netanyahu earlier this year said supports Ukraine but ruled out sending Kyiv an Iron Dome system over concerns that it could be obtained by Iran, which would greatly jeopardise Israel's security.

Several other countries have also expressed interest in buying Iron Dome systems in recent years, including Germany, Romania and India. 

A naval version of the Iron Dome to protect ships and sea-based assets was also deployed in 2017.