“Object 4202” is a symbol of the latest Russian project in the field of modern military hypersonic aircraft. According to authoritative foreign analytical centers, its successful implementation can offset the advantages in the field of strategic weapons that the United States intends to gain over Russia as a result of the deployment of a global missile defense system.
How aircraft are classified by flight speed
According to their speed characteristics, aircraft are divided into subsonic, supersonic and hypersonic. Moreover, their flight speeds are usually expressed in the form of dimensionless quantities that are multiples of the so-called. Mach number, named after the Austrian physicist Ernst Mach, and denoted by the Latin letter M. Mach number is a dimensionless quantity and can be simplified can be defined as the ratio of the speed of an aircraft to the speed of sound in air at a given height. Therefore, the speed of an aircraft in 1 M (or M = 1) means that it flies at the speed of sound. It should be remembered that with height the speed of sound decreases, therefore, a value of 1 M at different heights will correspond to different values, expressed in km / h. So, at the speed of 1 M the earth corresponds to 1224 km / h, and at an altitude of 11 km - 1062 km / h.
The speeds of supersonic aircraft cannot exceed 5 M (or M = 5), while hypersonic aircraft fly just at speeds above 5 M. Moreover, they can also maneuver using aerodynamic forces arising during flight in the air, and also plan for distances much larger than at hypersonic speeds.
Physical grounds for the allocation of hypersonic aircraft
The 5 M boundary between supersonic and hypersonic aircraft was not chosen by chance. The fact is that when this speed is reached, the nature of the course of aerodynamic and gasdynamic processes, respectively, near the aircraft body and inside its jet engine changes significantly. First, the boundary layer of air flowing around the aircraft, at a speed of 5 M, is heated to a temperature of several thousand degrees (especially in front of the frontal part of the aircraft), and the gas molecules that make up the air begin to decay into ions (dissociate). The physicochemical properties of such an ionized gas are significantly different from the properties of ordinary air, it tends to enter into chemical reactions with the surface of the aircraft, intense convection and radiation heat exchange occurs between it and the flowing stream. Therefore, the thermal protection of the aircraft should not be worse than that of the American "space shuttles" or the Soviet "Buran".
In addition, hypersonic aircraft need a very special jet engine design, which is not similar to any of the known types. The fact is that in the well-known aircraft engines of supersonic aircraft, the flow rate of air taken from the atmosphere during the formation of a fuel-air mixture inevitably decreases to subsonic (otherwise it is impossible to enter the right amount of fuel into the air). In hypersonic aircraft, such a decrease in the air flow rate is unacceptable - due to the law of energy conversion, this will cause such an overheating of the engine structural elements that no known material can handle.
Design features
The hypersonic aircraft engine (in its simplest version) is similar to two articulated funnels, one of which serves as an air intake (the narrow part is a kind of compressor combined with a fuel injector and also acts as a combustion chamber), and the second funnel is a nozzle for the exit of burnt gases creating cravings. Such an engine can be placed only under the fuselage of the aircraft, which creates a certain appearance of hypersonic devices.
However, such an engine cannot operate at speeds less than 5-6 M, since the compressed stream simply does not warm up to the temperatures necessary for complete combustion of the fuel. Therefore, the most realistic way to accelerate a hypersonic aircraft to the required engine starting speed (at least at the present stage) is to use a detachable accelerator as the first stage, sometimes in combination with an accelerator aircraft. The photo below shows the American X-52 hypersonic aircraft mounted under the wing of the B-52 strategic bomber.
State of work on hypersonic aircraft in the USA
The United States has long begun developing new types of offensive weapons. First of all, these are hypersonic aircraft. So, within the framework of the DARPA Falcon Project, a rocket glider, designated HTV-2, is being developed, as well as projects of Boeing corporation hypersonic devices (X-43, X-51) equipped with ramjet engines like the one shown in the photo above. They are capable of carrying warheads weighing up to 450 kg, which can be either nuclear warheads or volumetric explosion bombs adjacent to them in power, capable of destroying the enemy’s protected CP.
The Boeing X-51 project will be able to reach speeds of up to 6400 km / h. For the first time this device was lifted in May 2010. There were two unsuccessful starts that ended in the destruction of the glider. After separation from the carrier aircraft, the device is accelerated by an additional booster made on the basis of a military tactical missile. Only upon reaching a speed of 5400 km / h does the jet engine of the aircraft itself turn on, which accelerates it to marching speed.
What have we lost from Soviet hypersonic developments
Of course, Russia had to fend off such a threat. Today, the corresponding Soviet developments are brought to mind. In the 80s of the last century, we had advanced developments in this area and even a finished product - the X-90 rocket plan of the Gala project. According to experts, the X-90 was successfully launched from an aircraft specially adapted for this purpose, and accelerated to 5400 km / h, which is the boundary of hypersound. But then came the "blessed liberals 90s", and the project was closed.
Russian response to Washington
Recently, the famous British military research center Janes Information Group published information that in February last year in Russia at the Dombarovsky training ground (Orenburg region) flight tests of hypersonic aircraft under the symbol Yu-71 (Yu-71) were conducted. Object 4202, which, according to the same center, is a generalized symbol for all Russian hypersonic developments, is part of our missile program.
But formally, it is not ordered by the military department from industry, but by the Federal Space Agency of the Russian Federation, which in modern conditions is not an odd “cover” for this work. The head performer of the ROC on the subject “Object 4202” is “NPO Mashinostroyenie” from Reutov, Moscow Region (the former missile design bureau of General Designer Vladimir Chelomey, who was the main developer of cruise missiles and medium-range ballistic missiles in the USSR).
By the way, on the site of this enterprise there is information that back in the late 50s of the last century, the MP-1 aircraft was created in the design bureau, capable of maneuvering in the atmosphere using aerodynamic rudders with hypersonic speeds. Its successful launch was carried out in 1961! So the theme “Object 4202” has a long history.
Prospects for the Russian "hypersound"
From a number of sources it is known that since the beginning of the 2000s, Russia began work on a “military hypersound” and is planning to install the Yu-71 product on a promising Sarmat ballistic missile. The new Russian hypersonic object 4202 is capable of accelerating to a speed of 11, 000 km / h and can carry a conventional or nuclear warhead. At such gigantic speeds, the device can maneuver while in the atmosphere at altitudes of 40 to 50 km. Therefore, it is impossible to intercept any of the latest missile defense systems.
And although the warheads of modern intercontinental ballistic missiles also reach hypersonic speeds in flight, their trajectories can be calculated, which means they can be intercepted by missile defense systems. The product Yu-71 (object 4202) is capable, unlike them, of maneuvering along a complex unpredictable trajectory, changing course and height, so it is almost impossible to intercept it.
Moreover, there is reason to believe that the first tests of the 4202 facility took place back in 2004. It was then that the deputy chief of the general staff of the Armed Forces of the Russian Federation Baluevsky reported at a press conference about tests of a hypersonic aircraft maneuvering in course and height.
