In the mid-fifties of the last century, France began to create its own strategic nuclear forces. In 1962, it was decided to create a ground-based component of the "nuclear triad" and the corresponding weapons. Soon, the basic requirements for the necessary weapons were determined and design work began. The first result of the new program was the emergence of the S-2 medium-range ballistic missile (MRBM). The appearance of these weapons made it possible to significantly increase the potential of nuclear forces in deterring a potential adversary.
The decision to create land-based missile systems appeared in February 1962. Its appearance was associated with the desire of official Paris to create all the necessary components of nuclear forces and get rid of the existing dependence on third countries. In addition, the delay in work on the subject of submarine ballistic missiles turned out to be an additional incentive. According to the 1962 plan, in the early seventies, the first military bases with silo launchers for medium-range missiles were to appear on French territory. The number of deployed missiles on duty was to exceed fifty. Strategic ground missile forces were to be subordinate to the command of the air force.
One of the surviving museum samples of the S-2 MRBM. Photo Rbase.new-factoria.ru
By the beginning of the sixties, French scientists and designers had accumulated some experience in the creation and operation of missiles of various classes. In particular, there were already some developments on the subject of short- and medium-range ballistic missiles. The existing ideas and solutions were planned to be used in the development of a new project. At the same time, it was required to create and work out some new concepts, technologies, etc. Due to the high complexity, leading industrial enterprises were involved in the work. Société nationale industrielle aérospatiale (later Aérospatiale) was appointed the lead developer. Nord Aviation, Sud Aviation and other organizations also took part in the project.
The French industry already had some experience in the creation of missiles, but the development of a project of a full-fledged combat complex was associated with noticeable difficulties. Because of this, it was decided to form the general appearance of the rocket and the systems necessary for it, and then test these ideas with the help of prototype technology demonstrators. The first version of an experimental rocket, designed for certain tests, received the symbol S-112.
Work on the S-112 project continued until 1966. After completion of development, the industry produced a prototype of such a rocket. Especially for testing new weapons, the Biscarossus test site was built, equipped with a silo launcher. It is noteworthy that this test site later underwent several upgrades, thanks to which it is still used today. In 1966, the first test launch of the S-112 product was carried out at the test site. This was the first launch of a French missile from a silo.
S-112 was the implementation of the ideas that underpinned the entire program for the creation of a new MRBM. It was a two-stage ballistic missile with solid fuel engines. The length of the product was 12.5 m, the diameter was 1.5 m. The launch weight reached 25 tons. An autonomous control system was used to monitor the maintenance of the required course. An experimental rocket was launched from a special silo with a launch pad. Used the so-called. gas-dynamic start with leaving the launcher due to the thrust of the main engine.
Tail section of the first stage. Photo Rbase.new-factoria.ru
Based on the test results of the S-112 missile, the French industry presented an updated draft of a promising weapon. In 1967, the S-01 rocket entered trials. In terms of size and weight, it almost did not differ from its predecessor, however, more advanced equipment samples were used in its design. In addition, there were noticeable design improvements aimed at improving the technical and operational characteristics.
The S-01 rocket compares favorably with the S-112, but still could not suit the customer. For this reason, the design work was continued. By the end of 1968, the authors of the project presented a new version of the missile system with the symbol S-02. In December, the first launch of an experimental S-02 rocket took place. Over the next few years, 12 more prototype rockets were used. As the tests were carried out, the design was fine-tuned with the correction of the identified shortcomings and an increase in the main characteristics. In the later stages of testing, the S-02 project was renamed S-2. It was under this name that the rocket was put into service and put into mass production.
To fulfill the requirements, it was proposed to build a rocket according to a two-stage scheme and equip it with solid-propellant engines. All this had a corresponding effect on the design of the main units of the product. The S-02 / S-2 rocket was a product with a total length of 14.8 m with a cylindrical body of large elongation. The rocket head fairing, which served as the warhead body, received a complex shape, formed by two conical and one cylindrical surfaces. The tail section of the first stage had aerodynamic stabilizers.
Diagram of a silo launcher. Figure Capcomespace.net
The casings of both stages, which also served as engine casings, were made of light and heat-resistant steel alloy. The wall thickness varied from 8 to 18 mm. Outside, the body carried an additional coating that protects it from the effects of hot gases at the start. Also, this coating was supposed to improve protection against the damaging factors of enemy nuclear weapons used against a silo with an S-2 missile.
The first stage of the rocket, which had its own designation SEP 902, was a cylindrical block with a diameter of 1.5 m and a length of 6, 9 m. There were fixed aerodynamic stabilizers on the rear of the hull. The tail bottom had holes for installing four nozzles. The own weight of the first stage structure was 2.7 tons. Most of the internal space was filled with a solid fuel charge of the Izolan 29/9 type with a mass of 16 tons. The charge was made by casting and fastened to the engine housing. The P16 solid fuel engine, which was part of the first stage design, had four conical nozzles made of high temperature alloy. To control the roll, pitch and yaw, the nozzles could deviate from the initial position according to the commands of the guidance system. A 16-ton charge of solid fuel allowed the engine to run for 77 seconds.
The second stage, or SP 903, was similar to the SP 902 product, but differed in smaller dimensions and a different composition of equipment, as well as the presence of an instrument compartment. With a diameter of 1.5 m, the second stage had a length of only 5.2 m. The design of the stage weighed 1 ton, the fuel charge accounted for 10 tons. The nozzle apparatus and control systems of the second stage were similar to those used in the first. There were also counter-thrust nozzles used when dropping the warhead. 10 tons of fuel provided 53 from the P10 engine operation. A cylindrical body of the instrument compartment was attached to the head of the second stage, which contained all the necessary equipment for control in flight.
The two stages were connected to each other using a special adapter, which included power elements and a cylindrical sheathing. The separation of the stages was carried out by means of preliminary pressurization of the interstage compartment and an extended pyrocharge. The latter was supposed to destroy the adapter, and the increased pressure facilitated this process, also simplifying the divergence of the separated stages.
General view of the launch complex. Photo Network54.com
The S-2 MRBM received an autonomous inertial guidance system, standard for such a weapon of its time. A set of gyroscopes and special sensors located in the instrument compartment of the second stage were supposed to track the change in the position of the rocket, determining its trajectory. When moving away from the required trajectory, the computing device had to generate commands for the steering machines that control the rotation of the nozzles. The aerodynamic stabilizers of the first stage were rigidly installed and were not used in the control system. Also, automation was responsible for separating the stages at a given time and dropping the warhead. The control system worked only on the active part of the trajectory.
For the S-2 missile, a special warhead of the MR 31 type was developed. It had a nuclear charge with a capacity of 120 kt and a mass of 700 kg. A detonation system was used, which ensures the operation of the warhead upon contact with the ground or at a given height. The warhead was placed in its own complex-shaped body and was equipped with ablative protection against temperature loads. An additional fairing covering the warhead was not provided for by the project.
The S-2 rocket had a length of 14.8 m and a body diameter of 1.5 m. The span of the tail fins reached 2.62 m. The launch weight was 31.9 tons. Two-stage solid-propellant engines made it possible to send a detachable warhead to a range of up to 3000 km. The circular probable deviation was 1 km. During the flight, the rocket rose to an altitude of 600 km.
A silo launcher was developed specifically for the new medium-range missile. This complex was a structure made of reinforced concrete with a height of about 24 m. On the surface there were only a concrete platform for the head of the mine and a movable cover with a thickness of 1, 4 m and a weight of 140 tons. To service a rocket or launch complex, the cover could be opened hydraulically. In combat use, a powder pressure accumulator was used for this. The main unit of the silo was a cylindrical channel for installing a rocket. The complex also included an elevator shaft and some other blocks. The design of the launcher gave a fairly high level of protection against an enemy nuclear strike.
The head of the rocket in the launcher. Photo Network54.com
In the combat position, the rocket with its tail compartment rested on the ring-shaped launch pad. The table was held in place by a system of cables, pulleys and hydraulic jacks, which were responsible for moving and leveling it. The central part of the rocket was additionally supported by several annular units, which also served as platforms for placing technicians during maintenance. To access the sites, there were several passages connecting the central volume of the launcher with the elevator shaft.
When deploying serial missile systems, silo launchers were built at a distance of about 400 m from each other and connected to command posts. Each command post, using multiple redundant communication facilities, could control nine launchers. To protect against enemy attacks, the command post was at great depth and had amortization means. A duty crew of two officers was supposed to monitor the condition of the missiles and control their launch.
It was proposed to store the S-2 missiles disassembled, with each unit being in a separate sealed container. To store containers with steps and warheads, special underground warehouses had to be built. Before the rocket was put on duty, containers with two stages were to be sent for assembly. Further, the missile without a warhead was sent to the mine and loaded into it. Only after that it could be equipped with a warhead transported separately. Then the cover of the mine was closed, and control was transferred to the duty officers.
In accordance with the plans of 1962, up to 54 MRBMs of a new type were supposed to be on alert at the same time. Even before the completion of work on the creation of the required weapons, it was decided to cut the number of deployed missiles in half. The reasons for the reduction of missiles to 27 units were difficulties with the simultaneous release of land and sea-based weapons. In addition, some economic difficulties began to appear, forcing plans to reduce the production of military equipment and weapons.
Rocket transporter. Photo Capcomespace.net
In 1967, even before the start of the S-02 missile tests, the construction of infrastructure and launchers for a new compound, which was to operate a promising weapon, began. The missile connection was proposed to be deployed to the Albion plateau. It was assumed that over the next few years, 27 silo launchers will be built, united in three groups of nine units each. The installations of each group were to be controlled from their own command post. In addition, it was required to build warehouses for storing weapons, an assembly workshop and other necessary facilities. The new formation was deployed on the basis of the Saint-Cristol airbase. 2,000 soldiers and officers were supposed to work at the base. The compound was designated brigade 05.200.
At the end of 1968, the program underwent another cut. It was decided to abandon the third group, leaving only two with 18 launchers. In addition, at the same time, an indication appeared about the beginning of the development of a new medium-range missile, which in the foreseeable future was supposed to replace the S-02 / S-2. In parallel with the construction of new facilities, the industry continued to test and fine-tune the rocket.
All the necessary tests of the S-02 product were completed in 1971, after which it was put into service under the name S-2. There was also an order for the supply of serial missiles. In August of the same year, the first serial S-2 MRBMs were transferred to the troops. Soon they were put on duty. The first missiles of the second group were loaded into the launchers about a year later. In September 1973, the first tests of a serial rocket took place. It is noteworthy that the first combat training launch of the serial S-2 was made not at the missile base of the armed forces, but at the Biscarossus training ground.
Over the next few years, the missile unit, subordinate to the command of the Air Force, conducted five more training launches, during which they worked out the work when receiving an order, and also studied the features of the operation of the missiles. In addition, the duty crews of the missile systems every day, seven days a week, were expecting an order to use their weapons, ensuring the country's security.
Warhead transporter. Photo Capcomespace.net
Until the spring of 1978, the S-2 medium-range ballistic missile remained the only weapon of its class in service with the ground component of the French strategic nuclear forces. In April 78, one of the groups of the 05.200 brigade, stationed on the Albion plateau, began to receive the latest S-3 missiles. The complete replacement of old missiles continued until the summer of 1980. After that, only new types of missiles were in the old mine complexes. Operation of the S-2 was discontinued due to obsolescence.
The total release of S-02 / S-2 missiles did not exceed several dozen. 13 missiles were assembled for testing. Another 18 products could be on duty at a time. In addition, there was a certain stock of missiles and warheads stored separately from each other. Warheads MR 31 were put into mass production in 1970 and were produced until 1980. During the tests and training launches, almost two dozen missiles were used. Most of the remaining products were later disposed of as unnecessary. Only a few missiles lost their nuclear warheads and solid fuel, after which they became museum exhibits.
The S-2 MRBM became the first weapon of its class created in France. For several years, missiles of this type were on duty and at any moment could be used to strike a potential enemy. However, the S-2 project had some problems, which soon led to the development of a new missile with improved characteristics. As a result, since the beginning of the eighties, the ground component of the French strategic nuclear forces has completely switched to S-3 medium-range ballistic missiles.
