Gremlin Hypersonic Guided Rocket (GZUR)

Russian developers together with the military in 2023 will begin joint state tests of the prospective Gremlin hypersonic missile. As the newspaper Izvestia writes, in the near future the developers intend to begin a new stage of bench firing tests of a ramjet engine of a prospective rocket, being developed under the designation Izdeliye 70 / "Product 70" [the Izdeliye nomenclature seemingly references the engine, and is seen in air-to-air missiles but not commonly among air-to-surface missiles]. In some documents, the product is called GZUR - GiperZvukovaya Upravliemaia Raketa - Hyper-Sonic Guided Rocket, but this is a generic category, rather than a term specific to and unique to this particular system.

“The name for this rocket, Gremlin, is so journalistic. So far, to be honest, they have not been officially reported. If you remember, recently there was a test of missiles on the Su-57, I would link such a sequence here,” said military expert Viktor Murakhovsky.

Gremlin is mythical creature from English folklore. Apparently, the term first appeared in the 1920s among British pilots and aircraft technicians, was recorded in print in 1929, and became widespread during World War II , including among the Americans. The first publication about the "phenomenon" of gremlins was a story in the Royal Air Force Journal on April 18, 1942. Gremlins are known to hate technology. Since World War II, all technical problems, from bicycles to spaceships, have been attributed to gremlins. They hate it and harm the people who use it in every possible way.

It's hard to believe, but the origin of the word "gremlins" is not lost in the mists of time. It has no Latin or Germanic roots and does not appear in bestiaries. Of unknown origin, OED says "probably formed by analogy with GOBLIN." Speculations in Barnhart are a possible dialectal survival of Old English gremman "to anger, vex" + the -lin of goblin. Today, one can often find theories that "gremlin" came from the Irish gruaimin - "evil little joker" or "bad-tempered little fellow" or from Fremlin's beer, which pilots allegedly loved to drink. The latest version seems to be the most plausible, because after two or three pints of beer on the plane, you can break anything.

In the short film Russian Rhapsody (1944), the American propaganda machine made a rather intricate movie. Hitler, angry at military failures, gets into a bomber and goes personally to take revenge on the accursed Russians. Suddenly, tiny multi-colored freaks appear on board, singing "We are Gremlins from Kremlin". Adolf tries to slaughter them, but they show him the mask of Stalin, scaring the dictator half to death. As a result, the gremlins destroy the plane, it falls and becomes Hitler's grave.

Gremlins are very small creatures, but one of their main abilities is the ability to shrink themselves even further. Gremlin is able to penetrate even the mechanism of a wrist watch and wedge a gear with his lifeless body. Even the most attentive person with a microscope can mistake a gremlin for a speck of dust - they can become so small. The second feature of gremlins is their analytical mindset. Studying the mechanism from the inside, they are able to detect the only detail, the incorrect functioning of which can lead to the complete destruction of the mechanism.

In terms of its dimensions, the Gremlin will be smaller than the previously adopted Kh-47M2 Dagger. Due to its small size, the GZUR can be used not only from the side of heavy bombers and MiG-31 interceptors. Long-range supersonic missile carrier Tu-22M, as well as fighters Su-57, Su-30SM and Su-35 can become its carriers. The size of the missile allows it to be placed in the internal compartment of the Russian "stealth fighter". Sseveral countries around the world are developing hypersonic weapons of various classes, including gliders, aeroballistic and cruise missiles. It is believed that such weapons will make it possible to more effectively hit different types of targets, since, due to the flight speed, it is difficult to intercept such ammunition with modern air defense systems.

The development of the Russian hypersonic missile "Gremlin" has been conducted by the Tactical Missile Corporation. the development work (ROC) "Gremlin" started in November 2018. Then the Ministry of Defense signed a contract for the execution of the order with the Tactical Missile Armament Corporation (KTRV).

The ducted rocket engine for the munition was created by the Soyuz Turaev Machine-Building Design Bureau. In 2020, the "product 70" was fired at the Ts-12 stand. This test stand was created for testing Soviet Storm intercontinental cruise missiles and was designed for many hours of testing rocket engines with simulated flight at high speeds and altitudes up to 25 km. Then it was used in numerous subsequent domestic developments of advanced weapons.

A "Prymotochnie Raketnyj Dvigateli" [ducted rocket engine] is not a rocket engine, but a jet engine. In fact, there is a fundamental difference here - a jet engine runs on atmospheric oxygen, a rocket engine - on an oxidizer that is carried with it. And they are mainly used on cruise missiles. Direct-flow motors cannot operate at low speeds - they need an incoming air flow to operate. So ordinary planes that take off and land at zero speed are not for them. But cruise missiles with a jettisonable upper stage (booster) are just that. The difference from a turbojet engine (turbojet) is in the absence of a turbine and a compressor driven by it, which injects air into the combustion chamber. In a ramjet engine, the pressure in the combustion chamber is created by the oncoming air flow, for which purpose it is accelerated with an accelerator (or, in American terms, a booster) to the appropriate speed ("Pick-up Mach" is called in Russian and is equal to this M about 1.5).

The currently known configurations of cruise missiles with supersonic ramjet engine (SPVRD) are based on the maximum integration of the sustainer stage and the launch and acceleration stage (SRC). The presence of the SRS is dictated by the fact that the SPVRD is effective only at high flight speeds, when its own thrust exceeds the aerodynamic drag of the rocket. The fulfillment of this condition entails the need for the rocket layout to allocate significant volumes for the placement of the SRC, and with severe overall restrictions on the placement of rocket weapons on the carrier, the rationality of the layout will be determined by the efficiency of using the available volume.

The desire to achieve effective use of this volume has led to the emergence of a so-called combined or integral unit on the basis of ramjet and accelerating engines, when the internal volume of the SPVJE combustion chamber is used to accommodate the accelerating engine. There are known methods of combining the sustainer SPVRD and the starting engine into a single system, when, for example, the solid fuel charge of the accelerating engine is directly cast into the SPVRD combustion chamber. This type of engine received the designation IRR (Integral RocRet Pamjet - combined rocket-ramjet engine or KRPD).

But the placement of the SRC inside the SPVRD combustion chamber has the following disadvantages: an increase in the mass of the sustainer stage due to the increase in the SPVRJ mass due to an unjustified increase in the length of the combustion chamber; unfavorable centering of the rocket in the area of its acceleration; and an increase in the mass of the rocket due to the need to ensure the strength of the rocket body during buckling from the CPC thrust force.

Technical details about the ammunition have not yet been disclosed. The Western military analytical publication Jane's Missiles & Rockets, back in 2017, suggested that it would reach six meters in length and weigh about 1,500 kilograms.

The new Russian development in terms of its technical characteristics will be in many ways similar to the Kh-32 air-launched cruise missile adopted in 2016, Konstantin Sivkov, a corresponding member of the Russian Academy of Missile and Artillery Sciences , suggested in an interview with PolitRussia. “Basically, this is a version of the anti-ship hypersonic missile for the Su-57 fighter, which will give it multi-role fighter functions. The rocket will weigh about 1.5 tons, and its flight speed is about six times the speed of sound. In this regard, it is comparable to our Kh-32 air-to-surface cruise missile, which, with a launch mass of about 6.5 tons, has about the same speed, ”the expert explains.

It is known that the size of the new missile is smaller than the Kh-47M2 "Dagger" hypersonic aeroballistic missile, which is carried by MiG-31K fighters. It is assumed that "Gremlin" will be included in the range of weapons for heavy fighters Su-30SM, Su-35 and Su-57. In this case, the ammunition can be placed in the internal arms of the Su-57 fighter. Presumably, the tests of this combat aircraft with the mass-dimensional mock-ups of the Gremlin have already taken place and were successful.

According to unconfirmed reports, the Gremlin's flight range will be 1.5 thousand kilometers. The rocket will be able to reach speeds of up to Mach 6. The subcontracts concluded by KTRV under the agreement for the Gremlin R&D Center also mention the seeker head (GOS) "Gran K-02" developed by JSC UPKB Detal Ural Design Bureau. It is known that a variant of this active-passive seeker is used on modernized anti-ship missiles. It is capable of providing the GZUR with the ability to defeat not only land, but also surface targets, including moving ones.

Earlier it became known that by the end of 2021 it is planned to complete state tests of the Zircon hypersonic cruise missile, and from 2022 to begin serial deliveries of ammunition to the fleet. Within the framework of state tests, it is planned to launch Zircons from submarines. It has not yet been disclosed whether the missile will have a variant with a nuclear warhead. Modern ammunition for long-range and strategic aviation is most often developed simultaneously with conventional and special warheads.