Army photo

The past — A Stryker, fitted with cage-style “slat armor” to stop RPGs, patrols Mosul back in 2006.

WASHINGTON: This year, the Army will fire live anti-tank warheads at two rival Active Protection Systems to assess how best to protect lightweight armored vehicles like its 8×8 Stryker. The contenders in this “live fire characterization activity” – it isn’t officially a test – will be the German Rheinmetall Active Defense System (ADS) and the Israeli Rafael Trophy Vehicle Protection System (VPS). Not participating, our sources tell us, is the American Artis Iron Curtain, which was the Army’s original pick to protect the Stryker but was subsequently rejected after Army testers found it wanting.

Now, the Rheinmetall ADS and the Rafael Trophy VPS won’t be installed on actual Stryker vehicles. Instead, they’ll be set up on specially designed armored targets. That will allow the Army to measure precisely what damage, if any, gets through the active protection systems from different kinds of attacks.

Rheimentall

Rheinmetall Active Defense System destroys an incoming threat at the last instant, by design

“The Army intends to conduct live fire characterization activities with the two hard-kill active protection systems on platform agnostic test rigs,” said Ashley John, spokesperson for the Program Executive Officer – Ground Combat Systems (PEO-GCS), in an email to Breaking Defense. “The performance data collected on these two systems will help determine potential suitability for ground combat vehicles, to include Stryker.”

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How the Trophy Active Protection System works (Rafael graphic)

A “hard kill” system, like ADS and VPS, is one that physically shoots down incoming anti-tank missiles and rockets. “Soft kill” decoys and jamming, by contrast, just  make the enemy miss. Hard-kill has worked well on heavy tanks. Israel, Russia and the US all use it. But, as the Army has painfully discovered, it’s much harder to get it to work on lighter vehicles – which need protection the most. For the Stryker in particular, while the reliable, affordable vehicle has become an Army workhorse around the world — with variants carrying everything from infantry to anti-aircraft missiles, 30mm cannon, jammers, and even lasers — the service has struggled for years to make it more survivable in high-intensity combat.

What’s the hold-up? Historically, hard-kill Active Protection Systems are heavy and bulky; they need a lot of electrical power to run radars and targeting computers; and when they intercept incoming warheads, they may cause them to prematurely detonate or burst into shrapnel – “residual penetration” that a heavily armored tank can shrug off, but which a Stryker or other lightly armored vehicle cannot.

The Germans and Israelis have taken different approaches to solving this problem. Rheinmetall’s ADS uses a large number of small explosive charges distributed around the vehicle, computer-controlled to detonate at the precise millisecond to cut apart incoming warheads just before they detonate. Rafael’s Trophy uses a compact missile launcher, which lobs mini-missiles at incoming anti-tank missiles and rockets to intercept them further out. There’s a big debate over which of the two approaches is safer, both for the vehicle being protected and for foot troops or nearby civilians.

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How Rheinmetall’s Active Defense System (ADS) stops incoming anti-tank warheads.

Rheinmetall has not made public which countries, if any, use its ADS. Rafael’s Trophy has a 10-year track record in Israel. It’s been in combat on Israeli Merkava tanks since 2011 and was picked for the American M1 Abrams in 2018.

Just this week, Rafael and its American partner, Leonardo DRS, announced they had completed urgent deliveries of enough systems to protect every M1 Abrams in four Army brigades. How many is that? While the Army and the contractors are leery of giving exact figures, a typical Armored Brigade Combat Team has six tank companies with a total of 84 Abrams, plus backup vehicles in case of breakdowns. With enough Trophy APS now delivered for four brigades, that would bring the total close to 400 systems – and a further contract for spare Trophies is in the works.

But the current Trophy APS is a multi-ton system. So while it’s been installed successfully on 60-plus-ton main battle tanks – Abrams and Merkava – the usual set of radars and launchers just doesn’t fit on lighter vehicles like the 30-ton M2 Bradley or the 20-ton Stryker.

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Rheinmetall Active Defense System installed on a Fuchs wheeled armored vehicle

By contrast, “distributed systems” like Rheinmetall’s ADS or Artis’s Iron Curtain rely on smaller sensors and relatively tiny, lightweight explosive charges. That means they can be installed on lighter vehicles – potentially even unarmored trucks.

Currently, the Army is buying a rival Israel active protection system for its Bradleys, Elbit’s Iron Fist-Light. But to compete for Bradley and Stryker, Rafael and Leonardo have developed a slimmed-down variant of Trophy, the Trophy Vehicle Protection System, that they say is up to 40 percent lighter. (The exact weight depends on how it’s installed on a specific vehicle). The latest version of Trophy VPS also requires less power to operate its radars and other electronics, a big bonus for vehicles like Bradley whose aging electrical systems are already overloaded.

Yet, the companies claim Trophy VPS performs just as well in testing as the full-size version. It even carries the same number of mini-missiles as the original, which is crucial, because that allows it to shoot down the same number of incoming threats before running out of ammo. But almost every other component has been modernized and miniaturized. Since Trophy system was first used in combat in 2011, sensors, processors, and power systems have all gotten lighter. The new components also consume less power, which lets the power supply shrink even more. The companies have even streamlined the wiring and used new, lighter-weight materials in the physical structure.

The resulting lightweight Trophy was first tested, to our knowledge, in Israel in 2018, installed on a M2 Bradley chassis. The US Army did at least some testing in 2019 to see how Trophy VPS would work on Stryker. But Trophy’s greatest test will come this year, in a head-to-head comparison with Rheinmetall’s ADS.