Israeli soldiers near an Iron Dome missile defense system in the southern city of Ashkelon on May 15, 2021.

Over 3,150 rockets have been fired by Palestinian militant group Hamas from Gaza into southern and central Israel over the past week, targeting both Israeli population centers and border villages. Approximately 90% of those Hamas rockets have been intercepted by Israel's Iron Dome missile defense system, according to Israeli officials.

Bystander videos have documented the anti-missile system in action: curving streaks of light, nearly resembling firecrackers, meet rockets mid-trajectory. Seconds later, a bright flash and loud boom, signaling the rocket's interception. Shrapnel falls to the ground.

Israeli officials credit the Iron Dome with saving thousands of civilian lives. They say Hamas rocket fire in recent days has killed 12 people, including two children. In Gaza, without a similar defense, the toll has been far greater: At least 213 people have been killed by Israeli airstrikes, including 61 children, according to the Health Ministry in Gaza.

When the Iron Dome technology was declared operational in 2011, it was regarded as a "game-changer" for modern warfare.

According to the Israeli Defense Ministry, the targeting system uses radar and advanced tracking technology to follow the trajectory of incoming projectiles and determine if they pose a threat to a major population center. After measuring the speed and direction of the rockets, the intercepting Iron Dome missiles are fired, intended to detonate the projectiles mid-air.

It's like a "bullet shooting down another bullet," the late "60 Minutes" correspondent Bob Simon reported in 2013. It applies the laws of physics to short-range rockets traveling between 500 and 1,000 miles per hour.

A constellation of Iron Dome "batteries" comprise the defense system, according to Israelis. Each battery has its own radar, command-and-control center and launchers that fire the Tamir interceptor missiles.

Currently, there are 10 Iron Dome batteries deployed throughout Israel, with each battery intended to defend 60 square miles.

According to Raytheon, a U.S. defense contractor that produces up to 70% of the components of the Iron Dome's interceptors, each battery has three launchers loaded with up to 20 Tamir interceptor missiles each.

The Iron Dome was developed with the support of hundreds of millions of dollars of aid from the United States government, backed by the then-Obama administration, according to congressional reports that track U.S. foreign aid to Israel.

U.S. aid for the project continued beyond its development, particularly as Israeli defense officials made technological upgrades to the system. In 2014, for example, during an escalation of violence between Israel and Hamas, the House and Senate approved a $225 million bill to restock the Iron Dome's interceptors.

Shooting down thousands of missiles quickly becomes an expensive proposition. The cost of the interceptor missile is about $40,000-50,000, according to the Institute for National Security Studies, a prominent Israeli think tank.

The U.S. government still provides critical financial support. A Congressional Research Service report outlines aid the United States has provided over the defense system's history, as of November 2020: "$1.6 billion to Israel for Iron Dome batteries, interceptors, co-production costs, and general maintenance."


Israel's Iron Dome missile defense system (left) intercepts rockets (right) fired by Hamas towards southern Israel from the northern Gaza Strip, as seen in the sky above Gaza overnight on May 14, 2021.

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