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Are Active Protection Systems Coming of Age?

Trophy armor protection system is successfully combat-tested

The modern battlefield changed again recently, though with all the recent developments in the Muslim world it would have been easy to miss what is one of the most significant developments in new military technology. On March 1, 2011, an Israeli Defense Force (IDF) Merkava 4 Main Battle Tank (MBT) on a mission near the border of the Gaza Strip was engaged by a Hamas anti-tank guided missile (ATGM) team. Armed with the Russian-made 9M133 Kornet-E (NATO Name – AT-14 Spriggan) ATGM, the Hamas team fired a missile at the Merkava, knowing full well that if the heavy ATGM hit, it would likely destroy the MBT and kill the crew. But just before impact, the missile was destroyed and the tank continued on undamaged. For the first time in actual combat, a battlefield tactical missile had been engaged by an active protection system (APS), and destroyed. And like the very first intercept by the Patriot PAC-2 against an Iraqi SCUD missile back in 1991, this engagement looks to have massive effects on future battlefield protection systems.

The duel between guns and armor has been a long one, with the past few decades generally showing armor as the winner. However, the last few years have seen penetration warheads and projectiles regaining their primacy, as large warhead missiles and hypervelocity kinetic penetrators are now able to defeat even the most advanced armor systems, like those of the M1 Abrams MBT. During Operation Iraqi Freedom in 2003 and the 2006 Israeli-Hezbollah War in Southern Lebanon, Russian-made heavy ATGMs like Kornet disabled or destroyed a number of U.S. M1 Abrams and Israeli Merkava 3 MBTs. For the IDF, this was more than enough to suggest that the days of invulnerability for heavy laminate armor systems like Chobham may be at an end, and that a new kind of protection system is needed.

Merkava with Trophy APS

A Merkava displays two of the flat phased array antennas either side of the turret, along with the two countermeasure launchers above and to the rear of them. The panels behind the countermeasure launchers are to protect the MBT crew from any backblast. Photo courtesy of Rafael Advanced

Enter the ASPRO-A Trophy APS, developed jointly by Rafael Advanced Defense Systems and Israel Aircraft Industries’ Elta Group. The Trophy APS is composed of an Elta EL/M2133 radar with four flat-panel phased array antennas with a 360-degree field-of-view around the vehicle being protected, tied to a computer that aims the countermeasure launchers. When the radar detects an incoming threat missile or projectile and the computer classifies it as “hostile” and “dangerous,” the Trophy APS then fires a spray of multiple explosively-formed projectiles from one of two trainable launchers. The projectiles  strike the incoming round, often destroying it completely if thin-skinned rocket-propelled ordnance like missiles and RPGs. In fact, in a series of tests run by the U.S. Department of Defense (DoD) Office of Force Transformation (OFT – Project “Sheriff”) in 2006, Trophy was judged the most effective of seven APS systems tested, hitting 30 out of 30 targets.

To be sure, ASPRO-A/Trophy is not the only active protection system in development or on the market. There are at least 10 other soft kill or hard kill active protections systems in various stages of development, but Trophy was the first to be tested successfully in combat. While Trophy is hardly a perfect system, improved versions are already in the pipeline. A version called “Trophy Light” for light and medium tactical and armored vehicles has been in development for several years. There is also work ongoing to address the known shortcomings of the existing Trophy system. The most important of these is that even “Trophy Light” weighs nearly 1,000 pounds, and the standard ASPRO-A system tips the scales at almost 1800 pounds. Keeping weight, volume, and costs under control will be key parameters for the engineers in Israel. Another problem with the existing Trophy system is its inability at present to deal with long-rod penetrators fired by main battle tanks. One possible solution may be derived from U.S. work on the 25mm XM-25 grenade launcher, which uses time-fused ammunition to explode over the heads of enemies. Using such technology, it might be possible to detonate a small charge next to an incoming long-rod penetrator, snapping it in half (they are long and thin) prior to striking the armor of the target vehicle.

For centuries, since the first use of armor to protect men in battle, there has been a continuing conflict between penetration and protection. There have been times when one or the other appears dominant and perhaps has won the battle for good. But history tells us that new technologies will always arrive, swinging the pendulum the other way. Laminate/composite armor systems (Chobam, etc.) gave way to hypervelocity/large warhead systems in the past decade. Now APS-type systems may be turning the balance back to protection. It will be interesting to see what develops next, and where.


John D. Gresham lives in Fairfax, Va. He is an author, researcher, game designer, photographer,...