After the Second World War new ways were formed on further weapon development with allowance for obtained experience. In the course of the war it became evident that destruction of strategic objects of military and economical potential in the enemy rear is extremely important. These tasks were placed on long-range bombers. Creation of nuclear weapon demonstrated its unique striking capabilities. An aspiration rose to develop a kind of weapon which later would named as a strategic offensive weapon.

One of the basic elements of the SOW is a family of various carriers of nuclear charges. The first specimens of this kind were USA bombers B-29, number of which grew rapidly. The threat of new military blocs and plans of attack on the USSR was a reason to take extraordinary measures on defense capacity assurance of the country, and the main goal was - to create the nuclear weapon.

In 1953 the nuclear charge was tested in the USSR, and thus the first basic element of the SOW appeared. The next necessary step - creation of NC carriers. The main requirements for them were: long range close to the intercontinental one, weight-lifting capacity of more than one ton, firing accuracy (deviation from the impact point) of no more than several kilometers. These requirements could be met by then bombers except the range. This shortage could be compensated by location of the base aerodromes closer to targets, and it was done by the USA AF.

This way was unacceptable for the USSR because of absence of heavy bombers until beginning of fifties and bases for them near borders of possible opponents. Besides, the serious disadvantage of bombers was very long time of target reaching and vulnerability to the AD. So, both the USA and USSR in the first after-war years had come to a decision to create long-range ballistic missiles.

During the Second World War the armies of belligerent powers used reactive missiles on smokeless powder. But their main characteristics were lower by one-two orders than requirements for the SOW carriers, therefore it was impossible to create the LRBM on the basis of their improvement.

The specialists turned their attention to the fact that utilization of engines burning liquid propellants may considerably increase both speed and range of rockets owing to much higher power potential of liquid propellants. Correspondingly, the rockets with LRE have better mass characteristics.

The most intensive investigations and development of LRE and rockets with LRE were conducted in Germany, beginning from the thirties of the last century. Creation of A-4 rocket in the first half of forties was an outstanding achievement on the way of new weapon development. The single specimen of a rocket from the times of the war ending, which may be evaluated as a prototype of the LRBM was the Germany rocket A-4 known also as V-2. The A-4 rocket used such liquid propellants as ethanol and liquid oxygen (LOX). Both USA and USSR concentrated their attention on this rocket and took measures for acquisition of all available data and materials in order to use an experience of Germany for creation of the LRBM as fully as possible.

The soviet specialists began study of the German rocket technology on a territory of the East Europe. This activity was concluded in 1946 by release of the government order on development of the research institutes, design offices, test centers and allocation of experimental plants. These measures allowed creation of all conditions required for development of the new weapon in the USSR in the shortest time.

FIRST GENERATION

The main organization on LRBM was NII-88 headed by S.P.Korolyov. Under his management and use of an experience of German experts the A-4 rocket was reconstructed under designation R-1. Then R-2 rocket was designed, the first strategic missile R-5 was drafted and its version R-5M as a nuclear ammunition carrier.

The propellant which used the liquid oxygen in rockets R-1, R-2 and R-5M was convenient for the first LRBM. The oxygen is a strong oxidizer, and mixing with an efficient fuel it brings a high specific impulse. The propellant LOX+ ethanol is not toxic, and this facilitates development and handling of engines and rockets. Both components are rather inexpensive and mass-produced. These advantages determined propellant selection for the first LRBM and ICBM.

However, a well-known disadvantage of this propellant is that the LOX shall be continuously kept at the combat position in the frosted-up steaming tanks. Because of that, an application of the LOX-based propellant is not advisable for military rockets or missiles. The rocket cannot stay for a long time in loaded state, and the ground tanks shall be replenished at an oxygen-produced plant close to the rocket. Consequently, the launch complex becomes cumbersome and hardly camouflaged. The pre-launch processing of such rocket is complicated and protracted. As a result, the wartime readiness of this rocket complex is extremely low.

Another disadvantage of R-2, R-5, R-7 and R-9 rockets was utilization of systems of the side radio-correction and range radio-control of a distance which were not protected against external interference. They required disposition of two radars and a station of radio-control at the launch site.

Taking all this into account, the Administration of the Head of Jet Armament which was a customer and user of missiles put a requirement that the future missiles would be protected against interferences, be veiled and be ready for a launch to the maximum extent.

The studies on possibility to create the LRBM with engines operating on storable high-temperature propellants began. Assimilation of these propellants was quite difficult, but they allowed prolonged stay of the rocket in the loaded state with considerable increase of its wartime readiness.

The persistent advocate of the idea to use the storable propellants for missiles was M.K. Yangel, the former Deputy Chief Designer of OKB- 1 in beginning of fifties, and then Director and Chief Engineer of NII-88. Namely in NII-88 an effectiveness of various propellants was investigated in the framework of a special scientific-research program. In that time the first Soviet tactical missile R-11 with a storable propellant was developed. It has the same range as the R-1, but two times higher operational readiness.

Creation of this missile had proved possibility and advisability to develop the LRBM with storable propellants.

SECOND GENERATION

During development of the first missiles designed by OKB-586 a possibility became evident to perfect them significantly. In particular, the potential of high-temperature propellant was not used in full measure, the time of stay duration in loaded state did not exceed one month. To bring the missile into the full readiness for a launch some tens of minutes or even hours was required depending on initial state.

This is why the OKB-586 made a proposal in the end of fifties to update all the three kinds of its missiles with designations R-22, R-24 and R-26. The first figure indicated the second step in elaboration of these missiles, the second one reflected a continuity of the preceding respective missile. The main new property of each updated missile was an encapsulated design and possibility to stay in the loaded state within up to one year. Besides, the proposed technological and design improvements provided considerable reduction of overall dimensions, lift-off mass and recurring cost.

The government was not able to accept this proposal, since at that moment preparation of five plants were in full swing for mass production of missiles R-12, R-14 and R-16. An exception was made for the R-26 missile, elaboration of which was assigned to the OKB-586 in May 1960 for replacement of R-16 missile. But some then events influenced a fate of the R-26 missile.

The USA were creating the high-temperature silo-based Titan-2 ICBM that was able to carry a nuclear charge of great power. The USSR was in possession of superpower thermonuclear charge, but there was no corresponding carrier. The missile design offices began elaboration of heavy and superheavy missiles.

In the OKB-1 a three-stage global missile GR-1 was designed.
The OKB-52, strengthened by design offices of V.M.Myasishchev and S.A.Lavochkin transferred to it jointly with nearby plants and technical documentation from OKB-1 and OKB-586 proposed three types of missiles: UR-100, UR-200 and UR-500. Here the letters "UR" means "Universal Rocket", and figures indicate a range of the missile's lift-off mass.

The light class missile UR-100 with the lift-off mass lesser almost by 3 times and with the charge power lesser by 1.5 times in comparison with the R-16 missile was proposed also as an anti-missile weapon.
The medium class missile UR-200 was of the same lift-off mass as R-16. The proposal was to use it also for injecting anti-satellite means as well as means of global sea reconnaissance into the Earth orbit.

The UR-500 missile of around 600t lift-off mass was able to carry the PU of around 20t mass and also solve some space tasks.
In the strategic plan of the country leadership two tasks had been formed: to increase as soon as possible a total number of ICBM (the USA in 1962 had 3 times higher fleet) and to create a missile that could carry the most powerful NC among existing ones, penetrate through the AMD to be developed and stay long time in loaded state at maximum battle readiness.

For solution of the first task the UR-100 missile was chosen. It was manufactured under an up-to-date technology, intended for a service in an encapsulated state condition inside a TLC, and was able be stored for several years inside a SL of simplified type.
Solution of the second task was imposed upon the new R-36 missile under development by OKB-586 in two versions - ballistic (8K67) and global one (8K69).

The super-heavy rockets were transferred into a space category. The further development of R-26 and UR-200 was stopped. However, all the innovative technical solutions of the R-26 rocket were used at creation of powerful R-36 missile.

THIRD GENERATION

In the end of the sixties - beginning of seventies a qualitative leap occurred in creation of strategic missile complexes. Many research institutes (NII) and design offices (KB) from various branches of industry had developed miniature digital computing devices, command instruments of high accuracy for control and targeting systems, nuclear charges of high specific characteristics, advanced propulsion systems, new schemes of launchers strengthening. A great amount of theoretical and experimental works was performed in the dynamics of rockets. These combined effects was a basis for creating the third generation of ICBM. The leadership of the country took a decision to modernize the missile complexes R-36 and UR-100 that composed the main potential of Strategic Missile Forces. The developers of these complexes were charged with a task to submit their technical proposals on competitive basis.
In 1967-1968 a couple of scientific research works was performed with allowance for the latest scientific-technical achievements. As a result, the Yuzhnoye SDO jointly with a number of NII and KB had formulated five basic principles of the impending modernization of strategic missile complexes, implementation of which should provide the qualitative increase of their combat effectiveness:

1. Increase of survival probability of the missile complexes in any conditions of combat actions, including nuclear or non-nuclear attacks, with following launches of missiles for a guaranteed back strike at targets of potential aggressors.
2. Increase of probability to hit the most important objects and economical regions at a territory of potential enemy protected by fortification means, as well as by upgraded CMD system in conditions of both back or preventive strike.
3. Increase of a stay of missile complexes in an autonomous mode both in the menacing time and after non-destructive strike.
4. Reduction of time required to put the MC on duty, as well as reduction of time for performing any service operations at simultaneous reduction of attending personnel for all service phases.
5. Increase of the guaranteed service life and inter-maintenance period.

These principles formed the basis of technical proposals for elaboration of three strategic stationary MC with silo-based missiles and high grade of protection against NE factors:

- R-36M MC with a liquid missile equipped with the SWH having 10 WHU or monoblock PU with charges of considerably higher power than SWH WHU (2 versions);
- MR-UR100 MC with a liquid missile equipped with the SWH having 4 WHU unified with WHU of R-36M MC and monoblock PU with more powerful charge than SWH WHU;
- RT-23 MC with a solid propellant missile equipped with 10 WHU

The first two complexes were planned to replace existing complexes
with heavy missile 8K67 and light missile 8K84. The third complex could be created depending on readiness of production of solid propellant mixture, large-scale blocks from them, shells and nozzle assembly of SRM from polymer composite material.
The specificity of combat tasks, conditions of combat application of the ICBM and their mass-scale deployment required to update such characteristics as:

- effectiveness of warhead payloads;
- firing accuracy and battle readiness;
- protection of launch devices;
- service properties;
- reliability and guaranteed service life

The technical proposals on modernization of liquid MC were submitted by Yuzhnoye SDO in 1968. The improved in 1969 proposals were based on following main principles realized in subsequent designs:

- elaboration of autonomous CS on the basis of digital computer, and a complex of command instruments of higher accuracy;
- creation of a multi-unit split-up warhead with individual targeting of WHU;
- elaboration of a complex of counter-missile defense penetration aids, including fault warheads operationable both outside and inside the atmosphere;
- full ampoulization (encapsulation) of the missile's propellant systems;
- constant service of the missile inside the transport-launch container, arrangement of all technological equipment and instrumentation necessary for the duty and launch on the TLP;
- mortar type launch of the missile out of the TLP installed in the SL;
- startup of the 1st stage engines in weightlessness environment after ejection out of the TLC;
- principally novel scheme of the missile mounting in the SL - suspending inside the damping system secured in the upper part of the silo;
- unification of the LD and CC structural elements.

The most principal moment in selection of the MC development way was decision on elaboration of the missile's CS on the basis of an onboard digital computer that in combination with the ground digital instrumentation installed on the TLC is a central control unit solving all mathematical and logical tasks with high accuracy, reliability and speed. Application of the ODC allowed provision of:

- solution of the full navigational task and reduction of methodical errors of the CS;
- possibility to increase the firing accuracy through determination and account of systematic instrumental errors;
- timely remote retargeting of missiles during the duty for any in advance listed objects;
- increase of CMC reliability owing to timely reception of information about the battle readiness of the missile, systems of TLC and CD, provision of timely exposure and elimination of malfunctions;
- full automatization of a control for all systems of the LD, TLC and missile during duty of the complex and launch of the missile.

The azimuthal targeting is provided by the fully automatic CS, without utilization of the ground geodetic network. The targeting system uses an automatic gyrocompass and quantized optical gyrometer, both in the LD. It provides preliminary determination of the azimuth's basic direction at beginning of the duty and its keeping in the course of the duty, including conditions of the nuclear attack against the launch area, as well as restoration of the azimuth's basic direction after attack.
The proposals were considered by the Defense Council in August 1969. Their great promise and validity were a foundation for a decision to charge the Yuzhnoye SDO with modernization of both complexes designated as R-36M and MR-UR100 with missiles 15A14 and 15A15, respectively.
The conceptual design of 15A14 missile was elaborated in December 1969.
The 15A15 missile, conceptual design of which was elaborated in September 1970, was designed and developed under maximum utilization of technical solutions proven already for the 15A14 missile. The high degree of succession promoted an acceleration of 15A15 development. The flight tests of both missiles began practically simultaneously.

FOURTH GENERATION

Rocket complexes of the fourth generation were created as a basis of strategic nuclear forces to support the military strategic parity for 1990-2000 period and as basic complexes for creation of the counteraction measures against the propagandized anti-missile defense system (AMDS) with the space-based elements. Operations of further improvement of the technical performances of liquid-propellant intercontinental ballistic missiles (ICBM) and successful completion of the cycles of long research and experimental development works of solid-propellant ICBM (their performances were not worse than the performances of the best world samples) were of the same importance in creation of the above complexes.

A basic task was to provide invulnerability in the counteraction to the missiles with very high shooting accuracy. It has led to creation of new directions in the domestic practice:

- creation of the missiles that can start directly in the conditions of nuclear attack of the area given;
- creation of mobile solid-propellant missiles with such vitality which could be achieved due to their mobility and indefinite location.

Both directions have been realized in development works of "Yuzhnoye" SDO. The following new decisions have been realized in practice:

- the control system (CS) with a stable element base and with diagram-algorithmic protection which provides working ability in the nuclear burst conditions;
- a multifunctional cover along all missile length for protection from harmful and destructive effects;
- command devices of continuous operation that provided high combat readiness;
- direct guidance methods which provide calculation of the mission during the flight;
- thermal regulation systems which are needed at continuous CS operation in the launcher.

The following items have been introduced in the solid-propellant missiles of the fourth generation:

- new methods of flight control: a chamber gas "blowing" system, a swinging nozzle and deviations of the main section;
- probes of the nozzle blocks which are foldable in the initial position;
- new types of propellants with unique power and operational performances and with optimum forms of charges on their basis;
- optimum designs of cruise solid-propellant rocket engines (SPRE): bodies of a "cocoon" type, central nozzles which are partially submerged;
- new structural thermal protective and erosion-resistant materials.

Application of the above complexes was a basis for negotiations and achievement of a new agreement for real reduction of the strategic offensive armament (SOA).
At present, "Yuzhnoye" SDO provides guarantee maintenance of the above complexes independently of their location and state belonging.

UNFINISHED DEVELOPMENTS

Some Yuzhnoye SDO project proposals and developments of strategic weapon were not embodied in the samples adopted for service by the USSR Strategic Rocket Forces, Navy, and Air Forces. The reasons and phases in which the developments were terminated were different.
As mentioned above, the technical proposals on R-22 and R-24 liquid propellant medium range missiles and R-46 heavy ICBM were not accepted. With the purpose of acceleration of development of R-14 and B-16 missiles, is the phase of Preliminary Design, the work on R-15 missile of D-3 system and R-21 missile of D-4 system for equipping the submarine of 639 project was terminated and the design documentation was transferred to SKB-385.

Because of inexpediency, the development of military version of R-56 rocket was terminated after the issue of Preliminary Design.
The further development of R-37 light class rocket in the PD phase and R-26 light class rocket before flight testing was stopped as the decision was made to create UR-100 and R-36 rocket complexes.
Because of insufficient, by GURVO assessment, combat effectiveness, after the PD issue and mock-up manufacture, the work on small-size one-stage ICBM R-38[8K610] was terminated.

The solid-propellant rockets developments encountered big difficulties. In the period since 1966 till 1973, many times, due to insufficient effectiveness of combat equipment and high cost of the rocket complexes, the PD of RT-21 [15Zh41] with three basing options and of RT-22 [15Zh43] with railway and silo types of launch were rejected. Temporary failures during the flight tests were the reason for termination of series production and all the work on RT-20P rocket complex with 8KE9 rocket. All the working documentation, design, methodological, and report materials were transferred to Moscow Institute of Thermal Engineering that was developing at that time "Temp-2C" rocket [15Zh42] according to analogous technical requirements.

Many times the requirements to RT-23 [15Zh44 and 15Zh52] rocket complex were changed, these rockets were never adopted for service despite the positive results of complete cycle of test development and flight tests. The last unfinished developments of combat rocket complexes of Yuzhnoye SDO were "Krechet", "Kopye-R", and RT-2PM2.

In 1991 the initial concepts were developed for the rocket complexes of fifth generation R-36M3 (Ikar) and RT-23M (Ermak), but the talks on START-2 and the break down of the USSR stopped their further development.