October 27, 2011: Palestinian terrorists are not happy. Last August, terrorist groups in Gaza thought they had come up with a way to get around the new Israeli Iron Dome anti-rocket system. They thought that all you had to do was fire at least seven rockets simultaneously at the same area being guarded by one Iron Dome battery. Islamic terrorists did this last August. One rocket got through, and killed an Israeli civilian. This “saturation” tactic is a problem with all air defense systems. But the saturation attacks turned out to be no more effective than firing many more rockets over an extended period. During two periods of intense rocket attacks last April and August, Islamic terrorists in Gaza fired over 300 rockets, most of them longer range ones aimed a large Israeli towns. For all this, they killed one Israeli. The Iron Dome system detected and shot down about 90 percent of the missiles that were headed for inhabited areas. That means only about a tenth of one percent of the Palestinian rockets were getting through to areas with people and buildings. Most of those rockets did not kill anyone,

Worse, Palestinians in northern Gaza could see Iron Dome in action, as those few rockets that were headed for an urban area, were knocked out of the sky by interceptor missiles. None of the Palestinian media will mention Iron Dome, but over the last two months Israeli intelligence has collected a lot of communications chatter in Gaza, and it indicates a demoralized population. Hamas had made much of how eventually the rockets being brought into Gaza by the thousands would bring Israel to its knees. Iron Dome in action has spoiled any enthusiasm for rockets destroying Israel. The rockets are now seen as a liability. The rockets can't hurt Israel much, and the Israelis shoot back, doing a lot more damage that the Palestinian rockets.

Israel has bought seven batteries of Iron Dome, to be delivered over the next two years. Two are in service, and a third will be ready by the end of the year. Each battery has radar and control equipment, and four missile launchers. Each battery costs about $37 million, which includes over fifty missiles.

During tests, Iron Dome detected and shot down BM-21 (122mm) and Kassam (crude models made inside Gaza) rockets. Iron Dome uses two radars to quickly calculate the trajectory of the incoming rocket and do nothing if the rocket trajectory indicates it is going to land in an uninhabited area. But if the computers predict a rocket coming down in an inhabited area, a $40,000 guided missile is fired to intercept the rocket.

This makes the system cost-effective. That's because Hezbollah fired 4,000 rockets in 2006, and Palestinian terrorists in Gaza have fired over six thousand Kassam rockets in the past eight years, and the Israelis know where each of them landed. Over 90 percent of these rockets landed in uninhabited areas, and the few that did hit inhabited areas cause few casualties. Still, a thousand interceptor missiles used against another major attack would cost $40 million. But that would save large quantities of military equipment and avoid many dead and injured troops and civilian. Israel already has a radar system in place that gives some warning of approaching rockets. Iron Dome currently uses that system, in addition to another, more specialized radar in southern Israel.

Over the last eight years, the Palestinians have had to fire about 250 rockets to kill one Israeli. With only two of seven Iron Dome batteries deployed, that has gone up to 300. With more Iron Dome batteries in action, it will take even more Palestinian rockets to do any damage.

Firing salvos of rockets at once is more difficult, and dangerous, than firing one or two at a time. The larger number of rockets takes longer to set up, and makes it easier for the Israelis to spot the preparations and fire a Hellfire missile. Moreover, the Iron Dome system control software can be tweaked to handle more simultaneous targets, and the fire control hardware can be upgraded as well. So the new terrorist tactic won’t remain successful for long.