Ukraine's Patriots aren't hard to find, and Russia's gunning for them with one of its best weapons — Putin's prized Kinzhals

• Ukraine's Patriots aren't hard to find, and Russia appears to be using one of its best weapons to hunt them.
• Russia lost one, but possibly as many as seven, of its tough-to-kill Kinzhals this month.
• The Patriot has its limits, but its best chance of taking out a Kinzhal is when it's the target, an expert said.

Russia's hunting the newest addition to Ukraine's air defenses with its advanced Kinzhal missiles, a weapon until recently hailed as unbeatable, in a major test of the US-made systems.

The American-made Patriot batteries defending Ukraine's cities, though they are considered to be among the most advanced in the world, are not that difficult to find. The radars emit telltale frequencies that Russia can detect, and Russia is targeting these batteries with one of its best and hardest to kill missiles.

The good news for Ukraine, a missile defense expert said, is the Patriot is very capable and has the best chance of killing the Kinzhal when it's the missile's target, but there's still limits to what it can do.

The US and Ukrainian militaries recently confirmed that earlier this month, in a first, a MIM-104 "Patriot" Air Defense Battery took out a KH-47M2 Kinzhal, an advanced maneuverable air-launched ballistic missile that the Russians have often and incorrectly touted as an unstoppable hypersonic weapon.

CNN, citing US officials, reported the deadly missile was targeting the Patriot, noting that officials suspect the Russians detected signals emissions that allowed them to target the system. It backfired though and resulted in the loss of the missile.

Russia has denied losing one of its prized "super weapons."

On Tuesday, there was another air battle, though much larger and more intense than the last. The details of the fight are still somewhat disputed and unverified, but it's clear it was a rough night in Kyiv as a salvo of Russian missiles screamed toward their targets.

Russia has claimed it destroyed a US Patriot system near Kyiv with a Kinzhal, indicating in an online update that the battery was the intended target. The defense ministry said "all assigned targets have been hit," adding that "a high-precision strike by a hypersonic missile system Kinzhal in the city of Kyiv hit a US-made Patriot anti-aircraft missile system."

Russia's claims it took out a Patriot with a Kinzhal were undercut by a Ukrainian announcement saying that all six of the Kinzhal missiles launched were shot down, along with at least a dozen other missiles.

A later CNN report citing a US official said a Patriot battery was likely damaged but not, as the Russians claimed, destroyed. Damage assessments are reportedly ongoing, but Reuters reported the damage appears minimal.

The reported kills during the overnight air battle would put Russia's total Kinzhal losses in less than a month at seven and, like the reported damage to a Patriot system, are a reminder that nothing is invincible. Neither the US Department of Defense nor the Ukrainian defense ministry responded to Insider's request for comment on the attack or clarification on what exactly happened.

Ukraine presently has just two Patriot air defense batteries in its arsenal, one from the US and another provided by European partners. These systems, which first arrived in April, fill a critical capability gap, targeting threats Kyiv's forces were previously unable to defend against, but the limited number means Ukraine can't really afford to lose one.

Yet, "it's always going to be at risk," Ian Williams, the deputy director of the Missile Defense Project at the Center for Strategic and International Studies, told Insider. "There's always a chance that the Patriot will get hit."

Missile defense is never flawless, and though it's difficult to take out an entire battery, all it takes is a successful strike to the phased-array radar to potentially render the system useless.

And in the electronic warfare space, the Patriot radar emits a signature that stands out among the noise. It could also be detected and tracked visibly via other surveillance, such as satellites or overhead drones.

Patriots are 'pretty easy to spot'

Russia has said the Patriot is a fair target, and in general,"if a radar is radiating," as it does when it's on and tracking targets, "no matter what radar it is, it typically is pretty easy to spot if you have the right equipment," Williams explained.

For the May 4 engagement, US officials suspect that Russian signals intelligence tracked the Patriot to its position outside of Kyiv.

The Patriot also presents a decent-sized target on the battlefield, as each battery consists of several launchers, command and control components, and a power station, among other things, as well as up to several dozen personnel. And it's not anywhere near as mobile as some of Ukraine's smaller shoot-and-scoot systems.

An attempt could be made to move it, but "evading an attack is really about tactics," like relying on effective early warning systems and radiating only when needed, Williams said, noting these options "minimize opportunities for Russian aircraft equipped with anti-radiation missiles to get in there and start taking shots at them, which they are always trying to do" to end Ukraine's defenses key to keeping Russian missiles and planes at bay.

Another potential solution is the use of decoys. Ukraine has successfully used decoys, such as wooden units, to trick attackers in the visible spectrum and protect its US-made High Mobility Artillery Rocket Systems (HIMARS).

"That's the kind of simple, low-tech thing that has been surprisingly effective in this war," Williams said. The Ukrainians may need a higher-end solution though to best the Russians out hunting for the Patriot's electronic signature.

Throughout the war, Russian forces have consistently sought to suppress and eliminate Ukrainian air defenses holding Russian aircraft at risk and threatening their ability to conduct air operations.

Ukraine's defenders have done well at protecting systems from threats like Russia's Kh-31 anti-radiation missiles designed to target radar systems, and overall system losses, Williams noted, have been lower than expected. But Russia is now gunning for its newly added systems with a missile that's tough to kill.

Putin claimed the Kinzhal can "overcome all existing and, I think, prospective anti-aircraft and anti-missile defense systems." Ukraine is proving that wrong, but it's still a formidable threat.

The Kinzhal, which is the Russian word for "Dagger," is known as the Killjoy among NATO forces. It's an advanced Russian system that shares design features with the Iskander short-range ballistic missile. It was adapted to be launched from the MiG-31, a high-speed Russian combat aircraft, at speed and altitude, and the missile's erratic flight path and hypersonic speeds complicate interception.

'Probably the best time' to take the shot

The Patriot, components of which are manufactured by US defense giants Lockheed Martin, Raytheon, and Boeing, has been significantly improved and upgraded since the controversies when it was first put to the test in combat decades ago, but, again, missile defense is not perfect and no system is batting a thousand.

Tom Karako, the director of the Missile Defense Project at CSIS, recently told Insider that the Patriot's ability to bring a missile down and the degree of difficulty in doing so depends on a number of different factors, specifically "what the heck the missile was doing at that exact couple-second window when the interceptor was in the basket."

When Patriot is the target, some of the features of the Kinzhal that make it particularly difficult for defenders, such as its ability to maneuver in flight, potentially become less of a problem.

In an intercept situation, "the closer you are to the target, the more kinematic flexibility you have to make that engagement," Williams told Insider, explaining that the missile eventually has to "stop maneuvering and bear down, and you have sort of maximum flexibility" if you're close to the target or are the target.

"The further you are away" from the intended target, he said, "then the physics get a little more challenging."

Talking about the reported May 4 intercept, Williams said that "if it was going for the Patriot itself, that is probably the best time to take that shot." That would be the optimal engagement scenario, he said, although intercepts become significantly more challenging in a barrage situation like the most recent engagement.

Russia can't afford to throw Kinzhals away

In the first intercept of a Kinzhal missile, the Patriot reportedly fired off multiple interceptors to bring it down. There aren't a lot of details on the second engagement of multiple Kinzhals, but photos and videos from that battle showed several surface-to-air missiles in flight.

Though this is standard shot doctrine and Ukraine seems to be using its Patriots sparingly, really only using them for high-end threats, Kyiv's forces have a limited supply of surface-to-air missiles, including Patriot interceptors, and it looks like Russia is attempting to overwhelm their defenses and strained arsenal.

Airpower and air defense experts have repeatedly emphasized the need to keep Ukraine supplied with Western SAMs, arguing this is critical to preventing the Russian air force from overrunning Ukrainian forces.

A diminished Ukrainian air defense capability would not only leave "Ukraine at greater risk from Russian missile attack but raise the prospects of the Russian Air Force resuming penetrating sorties into Ukrainian airspace," Williams wrote in a recent CSIS analysis.

He asserted that "to the extent possible, replenishing Ukraine's air defense capacity should remain a priority for Western military aid for the foreseeable future."

That said, Russia is estimated to have only a limited supply of Kinzhals and likely can't produce them in any significant quantity, a problem possibly exacerbated by industry constraints, consequences, in part, of Russia's aggressive invasion of its neighbor last year. Russia has faced significant shortages in its precision-guided munitions stockpiles that have forced it to turn to cheaper yet less effective alternatives like Iran-made exploding drones.

Ukraine's Patriot capacity, Williams suspects, "is actually bigger and deeper than these kinds of ballistic missiles." If that's the case, Russia can't really afford to throw them away gunning for Ukraine's Patriots, especially half a dozen of the missiles at a time.