By Dan Williams
JERUSALEM (Reuters) - A new Israeli air shield against rockets more powerful than those intercepted by Iron Dome in the Gaza conflict passed its first field test last week after being rushed through development, officials said on Sunday.
They said that David's Sling, billed as Israel's answer to the longer-range missiles of Lebanese Hezbollah guerrillas and Syria, shot down a target rocket in a secret November 20 desert trial that coincided with fierce shelling exchanges between Israel and Palestinians in the Gaza Strip.
Worried about deteriorating security on the fronts with Gaza, Lebanon and Syria, and the international showdown over the disputed nuclear program of arch-foe Iran, Israel has been accelerating work on its multi-tier missile shield, with extensive help from the United States.
A source in Israel's defense industries said David's Sling was originally scheduled for live trials in 2013, and that this was brought forward "given the general sense of urgency".
David's Sling uses technology similar to that of the Iron Dome system, which Israel says had a 90 percent success rate, intercepting 421 of the rockets fired from Gaza in eight days of fighting that ended in a ceasefire on Wednesday.
Also known as Magic Wand, David's Sling is being made by Israel's state-owned Rafael Advanced Defense Systems Ltd and U.S. firm Raytheon Co.
"The completion of the program will be a significant layer for Israel's multi-tiered anti-missile defense system," Defense Minister Ehud Barak said in a statement
Iron Dome is the lowest of the tiers, tackling the guerrilla rockets of Gaza and Hezbollah. It was originally meant to handle ranges of up to 70 km (45 miles), but designers say this is being expanded to some 250 km (155 miles).
The top-most tier is Israel's Arrow ballistic interceptor, designed to shoot down long-range Iranian and Syrian missiles at atmospheric altitudes - high enough so that any non-conventional warheads they might carry would be safely destroyed.
David's Sling would serve as a bridge between Iron Dome and Arrow, Israeli officials say, blocking out rockets that prove too fast and powerful for Iron Dome, or any ballistic missiles that are missed by Arrow.
Israel has already deployed the second generation of Arrow, known as Arrow II, as well as Iron Dome. The latter, also manufactured by Rafael, shot down hundreds of Palestinian rockets during the Gaza fighting of November 14 to 22.
Sayyed Hassan Nasrallah, leader of Hezbollah, which has been armed and funded by Iran, warned Israel on Sunday that thousands of rockets would rain down on Tel Aviv and cities across the Jewish state if it attacked Lebanon.
The Fajr-5s, with a range of some 75 km - able to strike Tel Aviv or Jerusalem - and 175 kg (386 lb) warheads, are the most powerful and long-range rockets to have been fired from Gaza.
But Hezbollah, which fought Israel to a standstill in a 34-day war six years ago, says it has been re-arming since then and has a far deadlier arsenal than Hamas, Gaza's Islamist rulers.
Like Iron Dome and Arrow, David's Sling has drawn interest from foreign clients, especially as the nascent system is also billed as being capable of intercepting cruise missiles.
Among potential customers have been at least two former Soviet satellite states in the Balkans, their diplomats told Reuters on condition neither they nor their countries would be named.
A recently retired Israeli defense official who has been briefed on the international contacts over David's Sling linked the Balkan interest to worries about Russian cruise missiles.
"There's a big bear next door that they want to keep away from their door," the Israeli ex-official said.
(Writing by Dan Williams; Editing by Alison Williams)