Ukraine says it shot down Russian Kinzhal missiles. What is the hypersonic weapon?
Ukraine has Patriot missile defence system that may have thwarted Russian strikes
Ukraine is claiming to have achieved a rare feat in warfare: the shooting down of sophisticated Russian hypersonic Kinzhal missiles.
The Russian air force fired six Kh-47M2 Kinzhals at targets in Kyiv, Ukraine's capital, early Tuesday, a weapon it has used sparingly since the early months of its invasion of its neighbour in February 2022.
Ukraine has not said if the U.S.-supplied Patriot missiles were used to thwart some or all of the attempted strikes, but it happened 10 days after the military said it brought down another Kinzhal, over Kyiv, using a Patriot missile defence system. The Pentagon also credited the Patriot system for thwarting the strike on May 6.
If a Patriot missile was able to intercept a Kinzhal, it's a significant development in air defence, according to experts.
Here's a look at what makes the Kinzhal different from other missiles Russia is using against Ukraine and why the ability to blow it out of the sky, before it strikes, is a big deal.
How is the Kinzhal different from other missiles?
The Kinzhal, which means "dagger" in Russian, is an air-launched ballistic missile.
When Russian President Vladimir Putin unveiled the weapons in 2018, he said they could penetrate both existing and future missile defence systems.
The Kinzhal is the cousin of the 9K720 Iskander-M — a short-range, ground-launched ballistic missile that Russia has used somewhat frequently throughout the war.
It's referred to as a hypersonic missile, meaning it travels at least five times faster than the speed of sound. Russia claims the Kinzhal can reach Mach 10 — that's 10 times the speed of sound, or 12,350 km/h — within a range of 2,000 kilometres.
Russia uses a modified MiG-31 fighter jet to launch the eight-metre-long missile from the air, something that helps boost its speed, said Sidharth Kaushal, a research fellow at the Royal United Services Institute, a defence and security think-tank in London.
But he called Russia's hypersonic description a "bit of conscious misdirection."
"It does fly at hypersonic speeds, but typically what we would mean when we use the term is something that's highly manoeuvrable at hypersonic speed," he said.
Tom Karako, a senior fellow and director of the Missile Defence Project at the Center for Strategic and International Studies (CSIS) in Washington, D.C., agrees that Russia's claims of the Kinzhal's hypersonic manoeuvrability may be exaggerated compared to that of weapons typically referred to as hypersonic, such as a cruise or a boost glide missile.
"[It] may or may not have been at hypersonic speeds, but it's nevertheless a sophisticated and challenging intercept problem," he said.
Why is it so hard to shoot down?
First of all, it's hard to intercept because of the altitude it flies at, which is between 30 to 40 kilometres above ground, Kaushal said, meaning it's above the range of many lower-tier air defence interceptors but also below that of ballistic missile defence systems that operate at much higher altitudes, such as the U.S. THAAD (Terminal High Altitude Area Defence) system.
"So, they can't necessarily intercept the missile in mid-course, but it can do so as it's descending towards its target," he said.
But the difficulty doesn't end there.
When the Kinzhal is in its terminal phase and descending rapidly toward a target, it releases six decoys that "mimic the radar signature of the warhead itself," Kaushal said.
"If an air defence system on the ground is firing interceptors, in principle, it may eliminate decoys rather than the warhead they're actually going for," he said.
Is this a success story?
Although Russia has used dozens of its small supply of Kinzhals over the course of the war, the May 6 interception — and possibly those on Tuesday as well — mark the first time Ukraine has been able to destroy this type of missile.
It would be "a testament to the capabilities of the system" if a Patriot missile system was able to intercept Kinzhal missiles, Karako of CSIS said, adding they "appear to have arrived just in time."
The United States, along with Germany and the Netherlands, donated Patriot missile defence systems that arrived in Ukraine last month.
Karako said he doesn't think it's necessarily going to change the course of the conflict for the Ukrainians, but it could "preclude them from taking bigger strategic hits."
But the possible success of the interceptions may have also come at a cost. Russia claims one of the six Kinzhals fired overnight was not intercepted and struck a Patriot system in Kyiv, which the Russian military said it was targeting.
According to CNN, the U.S. Defence Department is assessing whether a Patriot system was damaged in the assault.
As for Russia, both Karako and Kaushal point out that Russia's supply of Kinzhals is limited, and it's not easy to replace them.
Kaushal said there were already a number of constraints limiting Russia's production of missiles before the war — including one major component manufacturer declaring bankruptcy — but export controls are also inhibiting its ability to acquire parts to make both Kinzhal and Iskander missiles, which have also been depleted over the course of the war.
"Whatever it was they felt they were targeting was worth the expenditure of a high-value missile," he said.