July 15, 2019:
In mid-2019 the U.S. Army confirmed that it is officially “still looking” for a suitable APS (Active Protection System) for its Stryker wheeled armored vehicles. Tests of lightweight versions the Israeli Trophy and the similar German ADS (Active Defense System) revealed problems with both systems when used on Stryker. The Trophy and ADS developers are seeking to address the problems encountered with Stryker which is, compared to heavier tracked armored vehicles like the M2 IFV (Infantry Fighting Vehicle) and M1 tank, less able to carry the extra weight of an APS and supply the electrical power required. These are not new problems and Israeli APS developers have developed several lighter APS systems that, of necessity, feature lower levels of protection and power consumption. These also tend to provide less protection.
There may be another solution. Earlier in 2019, the army announced it was developing a master defense system for vehicles that will control one or more APS systems, each with different capabilities. This effort was influenced by the failure to find a suitable APS for Stryker and similar light armored vehicles used by the marines. Noting existing efforts to develop lightweight APS systems the Americans came up with MAPS (Modular Active Protection Systems). This was already being developed by an American firm before the army picked up on it. MAPS is designed to link different types of sensors (such as built-in sensors found on the most modern tanks) with defensive systems for different types of threats. This would make it easier for a MAPS equipped vehicle to upgrade APS capabilities quickly.
The current MAPS has only one APS capability; to disable wireless electronic guidance systems of incoming ATGMs (anti-tank guided missiles). MAPS has done very well with this capability. The next step is to integrate a module that handles the non-electronic (or wireless electronic) guidance systems found in many common portable anti-tank weapons (like RPGs/rocket-propelled grenades and wire-guided TOW ATGM) that are still around.
During the recent (2012-18) fighting in Syria RPGs and TOW systems (both the U.S. original or the Iranian copy) were a major cause of damage to (or destruction of) even the most modern tanks, like the Russian T-90. MAPS is being developed to not only deal with more types of threats but to make it easier to update as with new threats, including those no one has thought up yet, show up. Thus the main feature of MAPS is the modularity that allows rapid updating of APS defenses on MAPS equipped vehicles. Meanwhile, the most effective APS out there concentrates on detecting and destroying any slow (sub-sonic) moving object coming at a tank. Supersonic objects are shells fired from a cannon, including the cannon mounted on tanks and these tend to be defeated by passive systems (composite armor and explosive bricks).
American firm Lockheed is trying to perfect the next generation APS using the MAPS approach. So far U.S. efforts have been coming in second to Israeli APS designs. Aside from world-class engineers and scientists, Israel has a unique advantage; their vehicles are under constant attack by anti-tank weapons. This threat adds urgency for Israeli firms developing APS defenses as well as “reality checks” from enemy use of missiles, RPGs and other weapons against new Israeli APS.
Other nations are accepting the fact that tiny Israel is the leader when it comes to APS. In 2018 the U.S. Army arranged to upgrade 261 of its M1 tanks with the Israeli Trophy APS and that was completed in a year. Trophy had already been tested on the M1. Trophy has been around for a decade and has gained considerable combat experience. The U.S. noted that Western tanks, like the M1 and Leopard 2 are vulnerable to the weapons Trophy defeats. This was demonstrated recently in northwest Syria where Turkey lost many German designed Leopard 2 and older American M60 tanks to Russian Kornet ATGMs. Russia also lost many T-90s to ATGMs as well. Had the Turks or Russians been using Trophy they would have reduced those losses considerably.
Because Israel has been a pioneer in APS development there are several Israeli firms developing and selling APS gear. One of those firms created the Iron Fist APS, which lost out to Trophy in the competition to get the lucrative contracts to equip Israeli tanks. In response, the Iron Fist manufacturer (IMI), despite losing out in 2010 to Trophy (from Rafael), continued development without government funding. As a result, Iron Fist developed into an APS that is lighter, more compact, easier to install and, on paper at least, has more features. Thus Iron Fist will be equipping lighter American armored vehicles like the M2. Iron Fist contains heat sensing as well as radar to detect threats and that includes rifle and machine-gun fire. Those weapons cannot damage armored vehicles but it is useful for the crew to know where the fire is coming from. The German ADS system is similar to Iron Fist and has been competitive, at least during realistic testing by prospective buyers.
A full-size Iron Fist installation can also jam guidance systems on some missiles and has a lower false-alarm rate. The lightweight version of Iron Fist has fewer features but this system can be installed on much lighter vehicles like trucks. While Iron Fist has not been proven in combat like Trophy the manufacturer says it has worked well in tests and that was enough to encourage the American and Dutch armies to evaluate it on some of their armored vehicles. The Israeli army also selected Iron Fist for its Nemer heavy IFV.
In 2018 Iron Fist replaced a similar American developed APS called Iron Curtain that was going to be used on Stryker. Iron Curtain was created by American firm Artis which began development in 2005 and was part of a Department of Defense effort to catch up in APS development. That did not work out and by 2018 Artis was dropped as a contender because the developers had not solved some key reliability issues.
Until recently Trophy was the only APS most people heard about. That is largely because Trophy was the first APS to perform frequently and successfully in combat. In 2010 the first battalion of Israeli Merkava tanks was equipped with Trophy. Then in 2011 Trophy defeated incoming missiles and rockets in combat for the first time. This included modern ATGMs like the Russian Kornet. A few weeks before the ATGM intercept Trophy defeated an RPG warhead, which is an unguided rocket-propelled grenade fired from a metal tube balanced on the shoulder. As it was designed to do, Trophy operated automatically and the crew didn't realize the incoming RPG warhead or missile had been stopped until after it was over. That is how APS is supposed to work and Trophy has proved to be the most reliable and effective APS out there. By 2012 Israel was convinced sufficiently to equip all the Merkava tanks in an armor brigade with the Trophy APS. Now the U.S. Army is equipping three brigades with Trophy for the 58 ton M1 tanks as well as some 27 ton M2 IFV (Infantry Fighting Vehicles) with a lighter APS. The 19 ton Stryker is still waiting for an APS that works for smaller, lighter armored vehicles.