The 15P696 mobile combat missile system developed in Leningrad became the forerunner of the legendary "Pioneer"
The first prototype of a self-propelled launcher of the 15P696 complex in field tests. Photo from the site
"Land submarines" - what can be hidden behind this strange, at first glance, term? Academician Boris Chertok, one of those people who created the domestic missile industry, called by this phrase mobile ground missile systems - a unique weapon, which the main opponent of the USSR in the Cold War could not copy.
Moreover, the term coined by Academician Chertok hides much more than just an analogy with submarine missile carriers. The United States, having failed to restore parity in the field of ground-based intercontinental ballistic missiles, after the creation in the Soviet Union of such missiles as the UR-100 and R-36 family and its successor, relied on nuclear submarines. It is clear that the submarine, which is very difficult to locate in the ocean, is an almost ideal site for storing and launching ballistic missiles. Moreover, they can be made not too long-range - it is enough to swim to the shores of a potential enemy, and from there even a medium-range missile will hit almost any place.
Unable to create an equally powerful nuclear missile fleet, the Soviet Union found its answer to the American approach - mobile missile systems. It is no coincidence that the Molodets railway combat missile system frightened the overseas strategists so much that they insisted on its categorical disarmament. But no less a problem for reconnaissance and, accordingly, targeting ballistic missiles, are mobile complexes on an automobile chassis. Go find such a special vehicle on the vast expanses of Russia, even if it is twice the size of an ordinary truck! And satellite systems cannot always help with this …
Self-propelled launcher of the 15P696 mobile missile system with the RT-15 missile in a combat position. Photo from the site
But the creation of mobile strategic missile systems would be impossible without the appearance of solid-propellant missiles. They, lighter and more reliable in operation, made it possible to develop and launch into serial production "land submarines" of the domestic Strategic Missile Forces. And one of the first experiments in this direction was a mobile ground missile system on a tracked chassis 15P696 with the RT-15 rocket - the first (along with the "mother" RT-2) serial solid-propellant medium-range missile in the USSR.
Liquid to the detriment of solid
Despite the fact that before the start of World War II and during it, the priority in development, and most importantly, in the practical use of rockets on solid-fuel engines belonged to the Soviet Union, after the war it lost it. This happened for a number of reasons, but the main one was that the gunpowder on which the shells of the legendary Katyushas flew were completely unsuitable for large missiles. They perfectly accelerated missiles if their active phase of flight took seconds. But when it came to heavy rockets, in which the active section takes tens, if not hundreds of seconds, domestic solid-propellant rocket engines (solid propellant rocket motors) were not up to par. In addition, in comparison with liquid-propellant rocket engines, they had an insufficient specific thrust impulse at that time.
The RT-15 solid-propellant rocket in a shipping container at the Arsenal plant. Photo from the site
All this led to the fact that in the Soviet Union, which received in its hands, albeit heavily thinned out by the allies, but still very informative documents and samples concerning German rocket technology, they relied on liquid engines. It was on them that the first Soviet ballistic and operational-tactical missiles with nuclear warheads took off. At first, American intercontinental ballistic missiles also flew on the same engines. But - only at the beginning. Here is how Boris Chertok talks about it in his book of memoirs "Rockets and People":
"Since the time of the classical works of the pioneers of rocket technology, it has been considered an unshakable truth that solid propellants - a variety of propellants - are used in those cases" when you need a simple, cheap, short-term propulsive device. " Long-range missiles should only use liquid propellants. This continued until the early 1950s, when the Jet Propulsion Laboratory at the California Institute of Technology developed a composite solid propellant. It was not gunpowder at all. The only thing common with gunpowders was that the fuel did not require an external oxidizer - it was contained in the composition of the fuel itself.
The blended solid propellant, invented in the United States, by its energy characteristics far surpassed all grades of our gunpowders used in rocket artillery. The powerful American chemical industry, at the prompting of the rocket scientists, assessed the prospects of the discovery and developed a technology for large-scale production.
Mixed solid rocket fuel is a mechanical mixture of solid fine particles of an oxidizer, metal powder or its hydride, evenly distributed in an organic polymer, and contains up to 10–12 components. Oxygen-rich salts of nitric (nitrates) and perchloric (perchlorates) acids and organic nitro compounds are used as oxidants.
The main fuel is metal in the form of highly dispersed powders. The cheapest and most widespread fuel is aluminum powder. Mixed fuels, even with a well-established technology, remain much more expensive in comparison with liquid components with the best energy performance.
When poured into the rocket body, an internal combustion channel is formed. The engine casing is additionally protected from thermal effects by a layer of fuel. It became possible to create a solid propellant with a running time of tens and hundreds of seconds.
New equipment technology, greater safety, the ability of composite fuels to sustainably burn made it possible to manufacture large charges and thereby create a high value of the coefficient of mass perfection, despite the fact that the specific thrust impulse of solid propellants, even in the best mixed recipes, is significantly lower than that of modern rocket engines. - liquid propellant rocket engines. However, the constructive simplicity: the absence of a turbopump unit, complex fittings, pipelines - with a high density of solid fuel, it makes it possible to create a rocket with a higher Tsiolkovsky number."
The first American ICBM on solid fuel "Minuteman" in the museum. Photo from the site
So the Soviet Union lost its priority, first in the creation of intercontinental ballistic missiles, and then began to yield in strategic parity. After all, solid-propellant missiles can be produced much faster and cheaper than liquid-propellant ones, and the safety and reliability of solid propellants allow them to be kept on alert constantly, with the highest degree of readiness - within one minute! These are the characteristics that the first American solid-propellant ICBM "Minuteman" possessed, which began to enter the troops at the end of 1961. And this missile required an adequate response - which still had to be found …
Three impulses for Sergei Korolev
Looking ahead, I must say that the real answer to the "Minutemans" was a liquid "weaving" - the UR-100 rocket, developed in OKB-52 Vladimir Chelomey (you can read in detail about the history of the creation and adoption of this rocket here). But at the same time as the "weaving", the first solid-propellant Soviet missiles were developed and tested - and also as a response to the Minutemans. Moreover, they were created by a man who for a long time was accused of being too addicted to liquid engines - Sergei Korolev. Boris Chertok writes about it this way:
“Korolev received not one, but three impulses at once, which made him the first of our chief designers and missile strategists to rethink, to change the choice in which strategic missile weapons were guided exclusively by liquid-propellant missiles.
The first impetus for the start of work at OKB-1 on solid-propellant missiles was the abundant information poured at the beginning of 1958 about the intention of the Americans to create a new type of intercontinental three-stage missile. I don’t remember now when we received the first information about the Minutemans, but when I was on some business in Mishin’s office, I witnessed a conversation about the reliability of this information. Some of the designers reported to him on the correspondence of the information received to our then ideas about the capabilities of solid-propellant missiles. The general opinion turned out to be unanimous: it is impossible in our time to create a rocket with a launch mass of only 30 tons with a warhead mass of 0.5 tons for a range of 10,000 km. On that temporarily and calmed down. But not for long.
The second impetus for the start of work on solid-propellant missiles Boris Chertok calls the return to the rocket industry of "an old ally in the GIRD, RNII and NII-88" Yuri Pobedonostsev. And the third - the appearance in OKB-1 at Sergei Korolev of another old rocket engineer, Igor Sadovsky, who once worked in the "rocket" NII-88. Boris Chertok recalls:
“Sadovsky persuaded the volunteers and assembled a small 'illegal' group to prepare proposals for solid propellant ballistic missiles (BRTT). The main core is three young specialists: Verbin, Sungurov and Titov.
“The guys are still green, but very smart,” said Sadovsky. - I divided them into three main tasks: internal ballistics, external ballistics and construction. The previous hardware connections helped me, I managed to agree with Boris Petrovich Zhukov, the head of the Research Institute-125 (this is our main institute for rocket and special gunpowders), on a joint theoretical study so far. And at NII-125, our old general boss Pobedonostsev runs a laboratory, where they are already working not only on paper, but also experimenting on the creation of powder bombs of a new composition and large sizes. Sadovsky told Korolev about his "underground" activities.
Korolev immediately reached an agreement with Zhukov and Pobedonostsev on "going out of hiding," and the development of a medium-range solid-propellant missile project began.
A family of Soviet solid-propellant ballistic missiles. Photo from the site
Sergey Korolev managed to attract people to these works who, it would seem, could hardly find themselves in the rocket theme - employees of the former artillery design bureau of General Vasily Grabin, the creator of many legendary artillery systems of the Great Patriotic War (guns ZiS-2, ZiS-3 and others) … Nikita Khrushchev's fascination with missiles led to the fact that the artillery was driven to the margins of the arms industry, and the former design bureaus and research institutes on this topic were handed out to missilemen. So Korolev had about a hundred specialists at his disposal, who enthusiastically took up the idea of working with powder solid-propellant rocket engines, which was quite understandable to them.
All this led to the fact that gradually the work, scattered and seemingly unrelated to each other, concentrated and began to acquire real features. And then, as Boris Chertov writes, “in November 1959, Korolev's penetrating power and annoying information from overseas worked at the highest level. A government decree was issued on the development of a missile for a range of 2500 km using ballistic powder charges with a warhead mass of 800 kg. The missile was named RT-1. It was a government decree on the creation in the Soviet Union of a solid-propellant missile launcher, the chief designer of which was Korolev. Immediately after the release of the decree, it was assigned the index 8K95”.
Solid "two"
Work on the RT-1 solid-propellant rocket lasted more than three years - and ended, it would seem, in failure. A total of nine missiles were launched, but the results of these tests remained unsatisfactory. In fact, it turned out that the "gunmen" only managed to create another medium-range missile - in addition to the already existing R-12 and R-14, developed in OKB-586 of Mikhail Yangel. It was clear that the military would refuse to accept it for service, and it was necessary to take steps to prevent the topic from being completely closed.
The RT-2 solid-propellant rocket on a transport vehicle during the November parade in Moscow. Photo from the site
Sergei Korolev found such a solution by submitting to the government and obtaining approval for the project of the RT-2 solid-propellant rocket, which is completely new for the Soviet rocket industry. Another quote from the memoirs of Academician Chertok:
“Starting to work on a new topic, Korolev showed the breadth of the problem, which sometimes annoyed high officials. He did not tolerate the principle "let's start, and then we'll figure it out", which was sometimes followed by very authoritative figures. From the very beginning of work on a new problem, Korolev strove to attract as many new organizations, competent specialists as possible, and encouraged the development of several alternative options in order to achieve one goal.
This method of wide coverage of the problem often led to the fact that “on the way” to the final goal, other, previously unplanned tasks were solved.
The decree on the creation of an intercontinental solid-propellant rocket RT-2 can serve as an example of such a broad scope of the problem. On the way to the final task, two more were solved: of the three stages of the intercontinental missile, there were missiles of medium and "shorter" range. The decree of 1961-04-04, issued before the end of the tests of the RT-1 (8K95) rocket, took a long time to prepare. Korolev patiently conducted difficult, tedious negotiations with people new to him and leaders of not always loyal departments. The decree approved and adopted for implementation the original project, which provided for three interrelated solutions for solid-fuel engines, which made it possible to create three mutually complementary missile systems:
1. Intercontinental missile complex RT-2, silo and land-based, with a three-stage solid-fuel composite rocket, at a range of at least 10 thousand kilometers with an inertial control system. The rocket of the RT-2 complex was originally intended for a unified warhead with the same warhead that was developed for the R-9 and R-16, with a capacity of 1.65 megatons. Korolev was the chief designer of the missile system.
2. A medium-range missile system - up to 5000 kilometers, ground-based using the first and third stages 8K98. This missile was assigned the index 8K97. The chief designer of the medium-range complex was appointed the chief designer of the Perm Mechanical Engineering Design Bureau Mikhail Tsirulnikov, he was also the developer of the first and third stage engines for the 8K98.
3. RT-15 mobile missile system, on a caterpillar track, with a possible launch from mines, at a distance of up to 2500 kilometers. The mobile launch rocket was assigned the index 8K96. For it, the engines of the second and third stages 8K98 were used. TsKB-7 was the lead organization for the development of the mobile complex, and Pyotr Tyurin was the chief designer. TsKB-7 (soon renamed KB "Arsenal") by the beginning of work on rocketry had extensive experience in creating artillery systems for the Navy. For all three missile systems, Korolev was the chairman of the Council of Chief Designers."
An early prototype of a self-propelled launcher for the RT-15 rocket. Photo from the site
The project of a solid-propellant intercontinental ballistic missile, on which the "royal" OKB-1 worked, eventually grew into the RT-2 rocket and its modernized version RT-2P. The first was put into service in 1968, the second replaced it in 1972 and remained on alert until 1994. And although the total number of deployed "twos" did not exceed 60, and they did not become a real counterweight to the Minuteman, they played their role, proving that solid-propellant engines are quite suitable for intercontinental missiles.
But the fate of the RT-15 turned out to be much more difficult. Although the rocket successfully passed flight-design tests and was even accepted for trial operation, in the end it never reached service. The main reason was that the designers of TsKB-7 failed to bring the RT-15 control system to a satisfactory state. But as a demonstration of the possibility of creating a mobile missile system "tag" played its role. And in fact, she paved the way for the next complex 15P645 - the famous "Pioneer" developed by the Moscow Institute of Heat Engineering under the leadership of Academician Alexander Nadiradze.
