Work on the P-20 project started in the spring of 1956. The objective of this project was to create a new projectile aircraft capable of speeding up to 3200 km / h, rising to a height of about 20 km, and covering distances of at least 2000-3000 km. 19 April 1956, OKB-240, headed by S.V. Ilyushin received a technical task for the development of such weapons. The project received the symbol P-20 and the code "Falcon". Initially, the Sokol system was proposed for use as a strike weapon for promising submarines. In 1957, there was an order to start work on the P-20C missile, which was planned to be used as part of the ground-based missile system, and later work began on the ship’s variant of the system and reconnaissance unmanned aerial vehicle.
Before designers OKB-240 was set a rather difficult task. To create a new rocket, it was necessary to conduct a large amount of research and development work that made it possible to form the overall look of a promising rocket. In search of the optimal appearance of the product, engineers had to carry out theoretical studies, as well as carry out tests of various models of promising technology. At the same time, in the early stages of check-ups, unusual techniques were used.
Mockup of the P-20 rocket during throwing tests. Probably the beginning of 1960. Photo Militaryrussia.ru
Due to the absence of wind tunnels suitable for testing a rocket with a flight speed exceeding 3000 km / h, it was decided to use non-standard techniques. During the tests, large-caliber artillery guns and a launcher that simulated a projectile were used. The model was placed in a special detachable pan, similar to that used with sabot projectiles, after which it was fired from a cannon. Shooting a model was carried out on a set of wooden frames with paper, equipped with electrical sensors. Behind such "targets" there was a mound, catching models.
The projectile projectile charge allowed the rocket model to be accelerated to the required speeds. With frames with sensors, cine, etc. flight stability studies, aerodynamic characteristics of the model, the influence of various forces, etc. were conducted. Such “artillery” model checks made it possible to check several variants of the missile's appearance and select the one that best meets the requirements.
The next stage of inspections was carried out using large-scale mock-ups of the rocket. Such products with a mass of about 200 kg were equipped with a set of special equipment and had their own solid propellant engine. During the tests, the aircraft raised such a model to a height of the order of 10-11 km, where the discharge occurred. After dropping from the carrier, the model turned on the engine and in a few seconds accelerated to the required speeds of the order of 2800-3000 km / h.
During the tests, the main features of the technical appearance of the rocket were identified. The product P-20 was supposed to get a cylindrical fuselage of high elongation with a frontal air intake of a cruise engine with a conical central body. It was proposed to equip the rocket with a middle swept wing of a large sweep and small elongation. According to some reports, folding wing hinges were designed as part of the wing design, designed to reduce the size of the product. In the tail of the fuselage should have been located two keels and all-rotary stabilizers. To control the flight of the rocket, it was proposed to use the ailerons of the wing, the rotary stabilizer and the rudders on the vertical tail.
The need to launch from a submarine or (later) from a ground-based launcher, as well as high requirements for flight speed led to the formation of an appropriate composition of the power plant. For the start, it was proposed to use two discharged solid-fuel engines PRD-39, each with 200-240. These devices were to be installed under the wing and discharged after the production of fuel.
A propulsive jet engine (ramjet) was proposed as a mid-flight power plant. A characteristic feature of the P-20 project was the use of a relatively long engine, which occupied almost the entire internal volume of the hull. For this reason, almost all units of control systems, warheads, fuel tanks, etc. placed in a small space between the walls of the engine and skin of the fuselage. In addition, some units contained the central body of the air intake.
It was proposed to use autopilot with inertial navigation system and astrocorrection to control the rocket throughout the flight. The development of the Sokol-A control complex was entrusted to SRI-303. Such equipment was supposed to ensure that the missile reached the target area with an acceptable deviation even at the maximum flight range. The terms of reference required a QUO of no more than 3 km. In the future, the creation of an active radar homing head capable of significantly increasing the accuracy of hitting the target was not excluded.
The calculation of the flight task, the introduction of data into the missile control system and the control of the launcher were to be carried out using the Sokol-P equipment. This system was to be installed on the submarine along with other units of the missile complex.
The absence of homing systems capable of searching for a target and attacking it could be compensated for by the relatively high power of the warhead. Product P-20 was supposed to carry a special combat unit of the type "46" developed by KB-11. The power of this ammunition was 1-3 MT, weight - 3 t.
The P-20 rocket had particularly high requirements with respect to the flight range, due to which it had to carry a large amount of fuel and have the appropriate dimensions. The total length of the product was 21 m, the maximum diameter of the fuselage was 2 m. The launch engines had a length of 5,4 m and a diameter of 1,1 m. The wing in the flight position had to have a span of 7,4 m. The firing span was 4 m. 21 level t.
For the use of the new rocket it was proposed to use a set of tools intended for installation on a submarine carrier. For the transportation of the missile it was proposed to use a container of length 22 m (according to other data, 25 m) and an external diameter 4,6 m, mounted on the deck of the submarine. One of the ends was supposed to be in the form of a sliding cover. Next to it, it was proposed to install rails and a starter.
The rocket was to be loaded into a container with an electric trolley. Floating to the surface, the submarine had to open the container and take the cart with the rocket to the rail launcher. Also at this time made the layout of the rocket wing. The rail launcher, together with the trolley and the rocket, had to rise to the starting angle 16 ° and be fixed in that position. After that, you could start, then remove all starters and perform diving. According to calculations, no more than 6,5 min were required for the launch preparation, launch of the rocket, and equipment folding.
In the middle of 1956, it was decided to develop a submarine carrier of the promising P-20 Sokol missile. Based on the multipurpose nuclear submarine of the 627A project, it was proposed to develop the P-627A project. Unlike the base submarine, the new one had to carry a long-range cruise missile with a special warhead. The task of such a submarine was the attack areal surface and coastal targets. The development of the P-627A project was entrusted to SKB-143 (now the Malachite SPMBM).
The overall design of the existing submarine has not changed significantly. All the improvements concerned only the installation of launch systems and instruments for controlling the missile complex. So, behind the cabin on a sturdy body was installed transport container for one rocket. The cover of the container was directed to the stern, and the rocket was to be positioned in the direction of the submarine’s movement. Behind the container on the deck it was planned to mount the launcher means intended for lifting the rocket to the starting angle. It was proposed to launch the rocket forward, through the wheelhouse.
The P-627A project was based on an existing submarine, which allowed speeding up work to a certain extent. In particular, in March 1957 of the year, before the completion of the development of a new project, the preparation for the construction of a new type of head submarine began. The work was carried out at the plant number XXUMX (Severodvinsk).
It was assumed that the project P-627A will be built only one submarine, which will become the platform for testing the new missile system. The new submarine of the 20 project was to be the serial carrier of the P-653 rocket, intended for full service as part of the navy. The development of this submarine started in the middle of the 1958 year. By the end of SKB-143 prepared a set of working drawings and handed it to the manufacturer. The new project was based on the design of the submarine type "627A", but now the submarine had to carry two containers for missiles. Both containers, as well as in the basic project, should have been located behind the cabin.
Requirements for the strength of containers and the need for quick firing of both missiles led to the emergence of the original design of the container lids. The lids were connected to a stern fairing swinging around a vertical axis. When turning the fairing to the right by 30 °, it was possible to take the rocket out of the left container and vice versa. Due to this and other features of launch vehicles, the 653 submarine needed no more than 10 minutes to ascend, launch both missiles and dive.
It was originally planned to build four submarines project 653. Subsequently, the command of the Navy, becoming interested in the new submarine and the P-20 rocket, expressed a desire to receive 18 boats. The lead ship of the series was to join the Navy in 1962 year, the rest - by the end of the decade.
In 1957, a proposal was made to develop a land version of the Sokol missile - P-20C. From the base product for submarines, it was supposed to differ mainly in the composition of the launch vehicles. The rocket should be transported on a special automotive vehicle, and for launch it was proposed to install a truss structure with a guide length of 16,7 m. Before launching, it should be raised to an angle of 10-16 degrees.
In 1959, a proposal appeared to develop a ship version of the P-20 missile system. The possibility of installing such missiles on nuclear cruisers of the 63 project, as well as a promising long-range strike cruiser, was considered. These ships could carry from two to eight missiles in several launchers.
At the end of 1959, the start was given to the development of a prospective reconnaissance unmanned aerial vehicle based on the P-20 rocket. By the middle of the next decade, it was necessary to present a system capable of conducting surface reconnaissance at a distance of up to 1500 km. The equipment of the new UAV should have been able to find surface objects, determine their coordinates, course and speed, and then transmit the data to the submarine carrier.
Long range strike cruiser with P-20 missiles. Figure Militaryrussia.ru
By the end of 1959, the P-20 project was ready for the start of tests related to the launch of mock-ups and high-grade missiles. A missile system based on the groundwork of the P-20C project was installed at the Faustovo proving ground. In the first tests, full-size rocket models with solid-propellant starting engines were to be used. In the course of these inspections, it was planned to study the work of the launching power plant and the missile derailment from the guide.
The first launch of the P-20 rocket was launched in December 1959. In January, 1960 launched another layout. In parallel with the conduct of the first tests, the assembly of a full-fledged prototype with a full set of onboard equipment was carried out. By the beginning of February, the assembly of this product was completed on 90%, but completion was not carried out.
February 5 The 1960 of the year was issued by a resolution of the Council of Ministers, which stopped work on the P-20 rocket project and complexes based on it. By this time, several new cruise missiles for the Navy had been created in our country, which had already reached the testing stage or had been adopted. Further work on the product P-20 "Falcon" was considered impractical. The project was closed, the documentation went to the archive, and the unfinished prototype for flight tests was disposed of.
The closure of the P-20 project led to the cessation of work on several related projects. Thus, the construction of the head submarine P-XNUMHA stopped. Already finished submarine units were used in the construction of the K-627 - the last boat of the 50A project. The plans for the construction of submarines project 627 were canceled. Also, shipbuilders had to revise plans for arming promising ships.
In the course of the Sokol П-20 project, the OKB-240 specialists carried out a large amount of various studies and tests, which allowed to solve several complex design problems. However, they did not manage to verify the correctness of the solutions found. By the time the project was closed, only flip tests of the two mock-ups were conducted, and the full-fledged flight model was not even built. For this reason, a full-fledged evaluation of the Sokol project is not possible, although the available information suggests that completing the work and equipping the fleet with a P-20 rocket would significantly increase its strike power.
Shirokorad A.B. Weapons of the domestic fleet. 1945-2000. - Minsk: “Harvest”, 2001
Yakubovich N.V. Unknown Ilyushin. Triumphs of the domestic aviation industry. - M .: Eksmo, Yauza, 2012