Hypersonic weapons: All the hype about the new technology

Russia’s military had deployed a new offensive weapon, the Kinshal, for the first time. It is the harbinger of a new arms race in which China and North Korea are also leading the way.

Three weeks ago, the Russian air force attacked the village of Delyatin in western Ukraine with a Kinzhal („Dagger“) hypersonic missile, and another attack took place in the south of the country in the Mikolayiv region. So much for the undisputed facts; opinions differ as to whether an underground weapons depot was really hit in the west and a fuel depot in the south, and whether the Kinzhal is indeed a wonder weapon.

But it is also true that this was the first time the missile was used in combat operations after Russian President Vladimir Putin proudly presented it four years ago. The two hits were probably also intended as a gesture of superiority with regard to NATO missile defence. Putin thus made good on his threatening gesture that Russian hypersonic weapons would „hit like a meteorite, like a fireball“.

Extra boost from fighter jets

The Kinshal is a solid-fuel medium-range missile based on the converted short-range Iskander. According to official data, its payload is 480 kilograms and it can be equipped with a conventional or a nuclear warhead. Russia states that it has a range of 2,000 kilometres.

The term hypersonic is used to describe aircraft that fly faster than five times the speed of sound (Mach 5). The approximately eight-metre-long Kinzhal is said to travel at Mach 6. This high speed is only possible due to additional thrust that the missile achieves by releasing Mach 2.7 fast MiG-31 fighter jets.

In November 2020, NATO looked into the new hypersonic weapons, and a document produced at the time expressed doubts about the capabilities described by Russia. Perhaps the Kinzhal only reaches Mach 5.

Unpredictable trajectory

However, NATO also stresses the need to develop a defence against the new weapons. The trajectory of ground-launched ballistic missiles describes a parabola, making it largely predictable. In the case of the air-launched and therefore „semi-ballistic“ Kinzhal, however, this is complicated.

The lower the hypersonic rocket flies, the later it can be detected by radar because of the curvature of the earth. Its kinetic energy, released into the airflow, creates an undulating trajectory that further complicates interception measures.

In addition, the Kinzhal is supposed to be manoeuvrable and fly unpredictable patterns, which could make interception by enemy missile defence systems impossible. There is no experience with this yet, which is another reason why the current missions in Ukraine are significant.

Avangard missile glider

Putin’s announcement in 2018 that the country had hypersonic weapons fuelled an arms race in which Russia is leading. As of 2019, the country also claims to have developed the Avangard hypersonic glider ready for use, which travels part of its trajectory in the stratosphere and is said by Russia to reach Mach 20.

Such a Hypersonic Glide Vehicle (HGV) is transported into orbit by a ballistic missile at an altitude of up to a hundred kilometres, from where it glides close to the target. The warhead is then released and, supported by the Earth’s gravitational pull, hurtles to the ground from a great height.

This also distinguishes the Avangard from the Kinzhal, which receives thrust from a rocket engine until impact.

US development lagging behind

Hypersonic weapons are supposed to close the gap between guided cruise missiles and fast but unguided ballistic missiles. Russia is not the only country with the technology. China already brought the DF-ZF missile glider to series-production readiness two years ago. North Korea carried out a third hypersonic test flight with a glider in January, and Pakistan may also be supported by China in its development. For the USA, after several setbacks in development, a finished system is not expected until next year at the earliest. India, Japan, Great Britain, France and Australia are also said to be working on it.

In addition to the missiles and gliders described above, so-called scram jets also fall into the category of hypersonic weapons. These are rockets with a so-called ramjet engine into which fuel is injected at high air compression. Unlike a jet turbine, however, there are no moving parts such as shovels.

The scram missile also does not function like a glider, but – similar to the Kinzhal – carries the warhead all the way to the target. The propulsion system is designed for cruise missiles; Russia claims to have equipped its submarine-launched Zirkon missiles with it. However, there are doubts about this.

Good detection by satellites

By flying temporarily in the stratosphere, missile gliders like the Avangard can reach any point on Earth. Attacks can therefore come from unforeseen directions, requiring a completely new deployment of missile defence systems – if they respond at all to projectiles travelling at such high speeds.

However, hypersonic weapons are up to 2,000 degrees Celsius hot because of their extreme speed. This creates a trail of ionised gas and emits an intense light in the infrared range, which is why the missiles and gliders are very easy to identify and track by military satellites.

Physicist David Wright and materials scientist Cameron Tracy draw attention to this in a recent article in the German science magazine Spektrum. The radiation could only be prevented if the missiles flew at less than Mach 6, which in turn would allow them to be countered by enemy missile defences.

Not a revolutionary development

The scientists also dispel the assumption that hypersonic weapons reach their target faster than ballistic intercontinental missiles, because these can also reach speeds of up to Mach 20. However, in order to save energy, they are directed towards the target in a high arc and only need more time to arrive for this reason.

However, a ballistic missile can fly at a lower altitude on a „lowered trajectory“ just as well, Wright and Tracy write. According to their calculations, a warhead would be delivered in this way with the same or even shorter flight time compared to a hypersonic weapon.

Finally, the scientists also have doubts about the touted advantage of the manoeuvrability of hypersonic weapons. According to them, one problem is the large forces required for each course change of the gliders, which must also be supersonic. Such manoeuvres reduced the speed and thus also the range considerably.

Changed perception of attackability

So there is some evidence that the capabilities of the new weapons are currently overestimated. However, despite its expected advantages, the technology has changed the political perception of attackability, security researcher Dominika Kunertova wrote last year in the Neue Züricher Zeitung.

Moreover, hypersonic weapons harbour the danger of nuclear escalation, because an attacked state cannot tell whether the zigzagging missiles, whose target cannot be precisely identified, are equipped with conventional or nuclear warheads.

The major powers should therefore include hypersonic weapons in future arms control agreements to limit their proliferation, Kunertova writes.

No treaty on the disarmament of medium-range missiles

The question is, however, which conventions are meant by this. In 2019, then US President Donald Trump terminated the INF Treaty, which had aimed to limit land-based intermediate-range missiles since the 1980s.

In view of Russia’s war of aggression on Ukraine, the confidence-building measures with the conclusion of new arms control agreements, which other experts also longed for, no longer seem realistic. Moreover, China, with its lead in hypersonic weapons, is unlikely to be persuaded to join. The government in Beijing has so far not been involved in any of the agreements in question.

So, after 40 years, there is again the threat of a medium-range arms race with the danger of nuclear war, but this time in the hypersonic range.

Image: A Russian MiG with a Kinzhal missile (MoD Moscow).

Autor: Matthias Monroy

Knowledge worker, activist, editor of the German civil rights journal Bürgerrechte & Polizei/CILIP.