Israel said that it will install a fifth "Iron Dome" battery before the end of the year, adding another installation to the country's missile defense system, which has proven itself this week, intercepting more than 150 rockets fired from the Gaza Strip.
The missile defense system, which can identify enemy rockets, determine if they pose a threat to populated areas, and destroy them within a matter of seconds, has been praised by Israel's leaders for saving hundreds of lives.
The system, however, comes with a steep price. Each interceptor missile, which includes a radar guidance system, costs $40,000. Israel has not disclosed how many missiles are required to take down an enemy rocket or how many interceptors it has fired, but experts estimate the country has fired $8 million worth of missiles in the past three days.
The Israelis are only trying to shoot down about a third of the rockets fired by militants, those on a trajectory towards populated areas, said Ben Goodlad, a senior aerospace and defense analyst at IHS Jane's. But of the rockets Iron Dome has targeted, the system is between 87 and 90 percent successful in destroying.
"That is an incredibly high success rate for the system," he said. "What isn't clear is how many interceptor missiles are fired. There may be two, three, or four fired at a one time to take down a rocket."
Palestinian militants working out of the Gaza Strip, a ribbon of coastline controlled by Hamas, have for years been stockpiling short- and medium-range rockets, built at a fraction of the cost of the Iron Dome missiles and then stored in highly populated areas near hospitals and schools.
Hamas is considered by the U.S. and Europe Union as a terrorist organization.
Militants this week fired rockets further into Israel than ever before, targeting the country's two largest cities, Tel Aviv and Jerusalem, but there were no casualties in those cities. Three Israelis were killed by rockets elsewhere in Israel.
"We are very pleased with the interception rates," aerial defense commander Brig. Gen. Shachar Shochet told reporters on Thursday. "We have intercepted dozens of Grad and Qassam rockets fired by Hamas and other groups, and prevented serious harm to our civilians."
Defense Minister Ehud Barak said the country the system had saved lives.
"No other country in the world has technology like the Iron Dome," Barak said. "Had the system not existed, many civilians would be in harm's way. However, the system is not a 100 percent foolproof defense, and does not absolve citizens of their duty to closely follow instructions given by Homefront Command."
The system is not perfect, and can be breeched by a large volley of rockets fired at once, a problem of "saturation," said former White House counterterrorism adviser and ABC News consultant Dick Clark.
Israel, therefore, plans to target the rocket stockpiles rather than continue to shoot down individual missiles. Israel has called up more than 60,000 reserve soldiers and appears to be planning a ground strike in Gaza soon.
Currently four mobile batteries equipped with sophisticated radar technology and missiles and on-board radar, are combined to create a shield over the country.
In 2006, 4,000 rockets were fired at Israel during a war with Lebanon that left 44 civilians dead. In response, the Israeli Defense Forces and Israeli defense manufacturer Rafael Advanced Defense Systems began developing Iron Dome.
In 2010, after tests proved effective, the United States began funding the program in part. Earlier this year, Congress authorized $600 million for the program, with instructions that the U.S. would eventually begin co-production of the system.