Experimental product "Tempest" on the slipway. Photo Wikimedia Commons
From August 1957 to December 1960, flight tests of the promising intercontinental cruise missile (ICR) "350" / La-350 / "Tempest" were carried out at the Kapustin Yar test site. In accordance with the tactical and technical requirements, this product had to show the highest flight performance. To accomplish this task, a lot of organizations and institutes had to be involved in the development of the project, which had to find and master promising solutions, materials and technologies.
Development of the "Buri" began in 1954 in accordance with the Resolution of the Council of Ministers on the creation of two intercontinental-range missile systems. The development of a complex with a cruise missile was entrusted to OKB-301 S.A. Lavochkin. The chief designer of the "350" theme was N. S. Chernyakov, scientific supervisor - M.V. Keldysh. At all stages, it was planned to involve a lot of other organizations and specialists in the project.
About three years were spent on the research and development part of the project with the search for basic solutions and subsequent design. The technical documentation for the "Bure" was prepared in 1957, which made it possible to launch the production of an experimental batch of missiles for future tests.
The Tempest project proposed the construction of a two-stage ground-based missile system. The first stage included two side blocks with liquid propellant rocket engines. Marching, equipped with wings, empennage, controls and warhead, was performed using a ramjet engine. The flight was to be carried out according to the commands of the control system, which included inertial navigation means and the AN-2Sh astrocorrection system. The warhead is a nuclear charge weighing 2350 kg.
Launch configuration of the rocket. Graphics Testpilot.ru
The total length of the product "350" in the launch configuration reached 19 m. The diameter of the sustainer stage was 2,2 m, of the blocks of the first stage - 1,6 m. The delta wing span reached 7,75 m. The mass of the rocket exceeded 97 tons, of which 34,68, 3,2 tons fell on the marching stage. According to the requirements, the speed of the sustainer stage on the trajectory was supposed to reach 7,5 M. The required flight range was 6,5 thousand km. During the tests, we got a range of approx. XNUMX thousand km
The problem of loads
Speed requirements imposed the most serious restrictions on the strength of the structure and on its resistance to various loads, incl. thermal. To study these issues, in 1954, NII-1 developed and built a supersonic wind tunnel with the ability to study heating and heat transfer. In 1957, NII-1 began operation of the Ts-12T gas-dynamic thermal stand, in which a full-size rocket model with all the equipment could be placed. This made it possible to study the effect of loads on the entire product assembly.
Calculations and studies have shown that in flight, the leading edge of the wing and air intake, as well as the engine channel, can warm up to 420 ° C. The outer skin temperature was lower, approx. 350 ° C, which was associated with the discharge of part of the thermal energy into the environment.
Based on the results of such studies, a search for suitable materials and technologies was carried out. Several grades of titanium and heat-resistant stainless steel were chosen for the manufacture of the airframe. In VIAM and MVTU them. Bauman developed technologies for processing and welding such metals and alloys. New non-metallic materials were also developed for use in seals, glazing, coatings, etc. In particular, the Leningrad State Optical Institute has developed a technology for manufacturing large-sized quartz panels. They were intended to form a flashlight above the astrocorrection sensors.
Launcher with a rocket in position. Photo Wikimedia Commons
Taking into account the requirements, design loads and available technologies, an advanced airframe design was developed. The rocket fuselage was made cylindrical with a variable section. In the bow there was a supersonic diffuser with a conical central body, inside which there was a compartment for the warhead. The engine air duct ran along the center of the airframe, and a cooled compartment of control devices and fuel tanks were located around it.
The blocks of the first stage were supposed to provide acceleration to 3M and also faced the problem of heating. In this regard, they were built from the same materials as the marching stage, but differed in a simpler design. They were made in the form of cylindrical units with conical head fairings. Almost the entire volume was given over to fuel and oxidizer tanks; in the tail were liquid rocket engines.
To obtain the required flight characteristics, the first stage needed two engines with a thrust of 68 tons each. The development of such products was entrusted to OKB-2 NII-88 under the leadership of A.M. Isaeva. The bureau already had a preliminary design of the engine with a thrust of 17 tons, and it was decided to use it in the context of the "Tempest". The new product received the designation C2.1100.
The new engine was made according to a four-chamber scheme; cameras and part of the piping were borrowed from the existing project. He had to use TG-02 fuel and AI-27I oxidizer. The supply of components to the combustion chambers was to be carried out by a turbo pump unit. Also, the engine was equipped with a separate circuit for isopropyl nitrate: it had to enter the gas generator and decompose into a steam gas, which set the TNA in motion. Each chamber of the C2.1100 engine, according to calculations, gave 17 tons of thrust - a total of 68 tons required.
The process of lifting the rocket to the launch position. Photo Testpilot.ru
The second stage ramjet engine was developed at OKB-670 M.M. Bondaryuk. Despite the seeming simplicity of the design, the creation of such an engine was particularly difficult. It was required to find materials corresponding to thermal loads from fuel combustion, to work out aerodynamic processes at the inlet and inside the engine, and also to solve a lot of other problems. By 1957, all these problems had been successfully resolved, resulting in a supersonic ramjet engine running on kerosene and giving 7,55 tons of thrust in cruising mode.
The NII-1 MAP branch under the leadership of I.M. Lisovich and T.N. Tolstousov. This project used the existing developments of different organizations. In particular, back in the forties, research on this topic was carried out by specialists from NII-88.
The goal of the NII-1 MAP project was to create a system capable of automatically finding the indicated stars, tracking their position and determining its own coordinates from it. For this it was required to solve several auxiliary tasks, such as the creation of the so-called. artificial vertical or providing noise immunity in all conditions. We also had to develop a calculating machine capable of converting astro-correction data into commands for the autopilot.
Back in 1952, before the start of work on the MKR "350", a prototype of the astronavigation system was manufactured. Its tests on the Il-12 plane showed high accuracy of keeping the flight direction. In 1954-55. this system has been refined and retested. The flying laboratory based on the Tu-16 flew at altitudes of 10-11 km at a speed of 800 km / h, and within 5-6 hours of flight, an error accumulated within 4-6 km.
The complex is ready to start. Photo Testpilot.ru
After certain modifications, the electromechanical navigation system with inertial devices and astro-correction was ready for installation on experimental rockets. In 1957, the production of pilot batches of such equipment for installation on prototype rockets began.
Confirmed by tests
The first launch of the "Tempest" was planned for August 1, 1957, but did not take place. Malfunctions in the isopropyl nitrate supply system prevented a regular start of the first stage engine. Fortunately, the engine instrumentation worked correctly and the rocket was not damaged. After the necessary modifications, on September 1, she was again prepared for flight. This time, the rocket left the launcher, but the control system prematurely gave the command to reset the gas rudders of the first stage. The rocket lost control and fell.
Then there were three more unsuccessful launches, in which the flight lasted no more than 60-80 seconds. In May 1958, the Tempest took off for the first time in a regular manner, took a given altitude, dropped the first stage blocks and turned on the ramjet engine. The speed of the sustainer stage reached M = 3. Then there were five more launches with failures at the start or at different parts of the trajectory. The next four flights were successful and showed that the rocket can accelerate to 3,2M, fly at a range of 5500 km and perform maneuvers, incl. turn by 180 °.
In March 1960, the last flight failure occurred with the loss of a rocket. Then, in March and December, we carried out two launches at targets at the Kamchatka ranges. In the first case, "The Tempest" in 121 minutes. flew to the target area, after which it could not go into a dive. The next and final flight was completely successful. At a distance of 6425 km, the product deviated from the target by 4-7 km.
Rocket in the first seconds of flight. Photo Militaryrussia.ru
In recent flights, experienced rockets with an improved propulsion system were used. They used the C2.1150 LPRE with increased thrust and the more compact RD-012U ramjet engine.
Reserve for the future
In the early stages of testing, the Tempest MKR faced various technical and design problems. They managed to cope with them, and in the future, the rocket showed a high level of performance - and the ability to solve real combat missions. As a result of further refinement, improvement and introduction of new components, the 350 rocket could well become an effective and successful strategic weapons.
However, in 1960 - according to various sources, in February or December - the Council of Ministers ordered to stop work on the "Storm" theme. The country's leadership decided that intercontinental cruise missiles are inferior to ballistic complexes in terms of their capabilities and potential. The simultaneous development of the two directions was considered impossible and inexpedient.
"The Tempest" did not go through the entire process of fine-tuning and did not enter service with our army. However, even in this case, the project yielded the most noticeable results. To develop a new MCR, it was necessary to build a number of research facilities and carry out a lot of research. A large amount of information was collected on the aerodynamics of high supersonic speeds, thermal processes, etc.
Model of the complex in the museum. Photo FAS
In addition, new materials and technologies were created. Most of these results of the "Tempest" project were subsequently successfully used to create new samples. aviation and rocketry. So, titanium, heat-resistant steels and other materials for the "Buri" are still actively used in the designs of aviation and other equipment. Modern technologies for the manufacture of such structures directly go back to the developments of VIAM and MVTU in the mid-fifties.
Some solutions of the C2.1100 project were later used in new rocket engine projects. The experience of creating the RD-012 / 012U ramjet engines was also useful in the development of a number of new products, such as some anti-aircraft missiles. Some of the developments of the past can be applied to the creation of modern hypersonic weapons.
The development of the "Earth" system was of great importance for our rocket and aviation technology. Astronavigation clearly demonstrated its capabilities and, thanks to this, subsequently found application in a host of new projects. In particular, it ensures high firing accuracy of intercontinental ballistic missiles.
Thus, the Tempest / 350 / La-350 project could not solve its main task, and the Soviet army did not receive a fundamentally new strategic weapon with the highest characteristics. At the same time, this project left a lot of scientific data and technical experience, which contributed to the further development of a number of areas. This means that the Tempest - despite the unsuccessful completion of the project - was not created in vain and brought great benefits, even if indirectly.