For the second time in a month an Israeli Merkava tank used its APS (Active Protection System) to defeat an incoming missile. The first incident, three weeks ago, involved an RPG warhead (an unguided rocket propelled grenade fired from a metal tube balanced on the shoulder). But this time it was an ATGM (Anti-Tank Guided Missile), possibly a modern Russian system like the Kornet E. This is a laser guided missile with a range of 5,000 meters. The 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 earlier incident 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.