How the Iron Dome defends Israel.

In the first three days of the conflict between Israel and Hamas, more than 300 rockets were fired into Israeli territory from Gaza. Most of them – 90 per cent of those that threatened civilian areas, according to Israel – were intercepted and destroyed by Israel’s renowned air-defence system, the Iron Dome

Shooting missiles to hit missiles is nothing new, but the brains of the Dome are truly unique, allowing the system to automatically identify a never-before-seen missile and shoot it down if it’s projected to hit a populated area. The technology keeps Israel a step ahead in what has become an arms race with no end in sight. Last year Iran announced it would produce a two-stage Fajr-5, capable of travelling twice as far as – and much faster than – the original. It’s only a matter of time before they appear.

How to shoot down a missile (see image)
1 A 6-metre Fajr-5 rocket leaves its launcher, carrying 90 kilograms of high explosive, at a speed of Mach 2,9, or 3 5 40 km/h.

2 A mobile radar unit detects the rocket and identifies its type. Within seconds a battle management and control (BMC) vehicle has converted the radar information into a trajectory and projected the location of impact.

3 If the missile threatens a populated area, an interceptor is fired.

4 As the interceptor nears its target, the missile receives trajectory updates from the BMC, but it relies on its own on-board radar as it closes in.

5 When the intercepting missile gets close enough, its warhead explodes, showering the target with shrapnel and destroying it. From launch to destruction, the entire process takes less than 5 minutes.

A missile-defence system in your pocket
When a rocket threatens Israel, warning sirens wail and Israeli radio and TV stations interrupt their broadcasts to alert as many residents as possible. But recently another way was devised to broadcast when to seek safety: an app. Red Alert, which reportedly gets its data directly from the Israel Defence Forces, is designed to alert users at the same time the siren does, providing the location and time of the projected strike, so even those who don’t hear the siren still get the warning. Trouble is, unlike the sirens, the app notifies people of every missile, not just the ones that threaten their area. Using it is kind of like being in a bar brawl and ducking every time someone else is punched: you get jittery. Your life is constantly interrupted, even when it isn’t threatened. Which is not to say that the app is a bad idea – just that it could use geolocation.