June 28, 2011:
After several years of development, the U.S. is sending an APS (Active Protection System) that combines the ability to destroy incoming rockets and missiles, as well as detect snipers and automatically point the vehicles' remote control machine-gun at the shooter. But there's more. The Iron Curtain APS (or IC APS) is different from earlier models in that it fires projectiles, to destroy incoming missiles or rockets, from close to the vehicle. The sensors and anti-projectile weapons are mounted on rails that go around the top of the vehicle (usually an MRAP) and the front of the engine compartment. The intercepting projectiles are fired downward. IC APS will be merged with CrossCue, a sniper detection system based on the older Boomerang. Together, they weigh less than half as much as current APS systems (which tend to weigh about a ton).
Meanwhile, the older APS systems are proving themselves in combat. Well, at least one of them is. Earlier this year, Israeli Merkava tanks used APS to defeat an incoming RPG rockets and anti-tank missiles. This was the first known combat success for APS. The first incident involved an RPG warhead (an unguided rocket propelled grenade fired from a metal tube balanced on the shoulder). Less than a month later, another APS took care of an ATGM (Anti-Tank Guided Missile). The ATGM was a modern Russian system, the Kornet E (a laser-guided missile with a range of 5,000 meters). The Kornet E launcher has a thermal sight for use at night or in fog. The missile's warhead can penetrate enough modern tank armor to render the side armor of the Israeli Merkava tank vulnerable. The missile weighs 8.2 kg (18 pounds) and the launcher 19 kg (42 pounds). The system was introduced in 1994 and has been sold to Syria (who apparently passed them on to Hezbollah and Hamas).
All this came a year after first equipping Merkava tanks with APS. The APS use occurred automatically, and the crew didn't realize the RPG warhead had been stopped until after it was over. That, however, is how APS is supposed to work. This first combat use is a big deal, because APS has been around for nearly three decades, but demand, and sales, have been slow. The main purpose of APS is to stop ATGMs, but on less heavily armored vehicles, stopping RPG type warheads is important as well. The Israeli Trophy APS uses better, more reliable, and more expensive technology than the original Russian Drozd (or its successors, like Arena) APS. For about $300,000 per system, Trophy will protect a vehicle from ATGMs (Anti-Tank Guided Missiles) as well as RPGs (which are much more common in combat zones.) Israel is the first Western nation to have a lot of their tanks shot up by modern ATGMs, and apparently fears the situation will only get worse.
Israel first encountered ATGMs, on a large scale, in the 1973 Arab-Israeli war. But these were the clumsy, first generation missiles that turned out to be more smoke than fire. More recent ATGM designs have proved more reliable and effective, but no nation, except Israel, has yet made a major commitment to APS. That may now change, simply because one RPG and one ATGM have been downed.
Most APS consist of a radar to detect incoming missiles, and small rockets to rush out and disable the incoming threat. A complete system weighs about a ton. Russia pioneered the development of these anti-missile systems. The first one, the Drozd, entered active service in 1983, mainly for defense against American ATGMs. These the Russians feared a great deal, as American troops had a lot of them, and the Russians knew these missiles (like TOW) worked. Russia went on to improve their anti-missile systems, but was never able to export many of them. This was largely because these systems were expensive (over $100,000 per vehicle), no one trusted Russian hi-tech that much, and new tanks, like the American M-1, were seen as a bigger threat than ATGMs.