Israel's Iron Dome missile defence system in action
19 November 2012 Last updated at 12:16 GMT
Israel's Iron Dome missile defence system took years to develop and was tested in combat for the first time in April 2011, when it knocked out a missile fired at the southern city of Beersheba.
During the current Gaza crisis, the system has been repeatedly praised by the Israeli military.
By Saturday evening the shield had intercepted 245 rockets from Gaza in three days, according to the army.
Ben Brown in Ashdod describes how it works.