Intercontinental RS-26 capable of performing medium-range missile missions
On the eve of the 55th anniversary of the creation of the Strategic Missile Forces (Strategic Missile Forces), rearmament is in full swing. The current pace, of course, is not comparable to the Soviet ones in the second half of the 70s and early 80s, when the troops received more than 200 missiles a year - intercontinental SS-17, SS-18, SS-19, medium-range SS-20. But these are no longer the crumbs of the 90s, when four Topol-Ms were commissioned a year.
As of January 2014, the Strategic Missile Forces were armed with 311 launchers (PU) of intercontinental ballistic missiles (ICBMs). The species includes three missile armies: 27th Guards (headquarters in Vladimir), 31st (in Orenburg), 33rd Guards (in Omsk). The most modern complexes are equipped with the 27th Guards - 96 newest mine-based and mobile-based Topol-M missile systems, as well as RS-24 Yars. The army consists of five divisions, the most powerful and numerous is the 60th missile division, which is armed with 100 ICBM launchers and 300 nuclear warheads.
RS-26 is the first swallow of the new, fifth generation. Let me note right away: all estimates regarding the design and tactical and technical characteristics of the new missile are conjectural and are based on rather scant information leaked to the press from representatives of the Ministry of Defense, the government or the president. Calculations are simple, theoretical directions for the development of missile weapons, which we are now observing, have long been known both in the United States and in the USSR, they have been created since the 60s.
"Bus" and "Blue Angels"
In November 1962, the US Navy's Special Project Office (SPO), together with the Air Force, began conceptual preparation of new combat equipment for ICBMs and submarine ballistic missiles (SLBMs). The plans of the two departments were to create a single combat unit (CU) of a new type for ICBMs "Minuteman" and SLBM "Polaris" B-3. Two options were considered, differing in the method of rearing the warheads. The first received the code name Mailman and assumed the creation of the so-called Bus - a platform with a guidance system and a propulsion system, from which the warheads were sequentially separated at the calculated points of the trajectory and then made an uncontrolled flight to the target.
The second method, called the Blue Angels, involved equipping each warhead with its own propulsion and guidance system. The first version later became the classic design of the MIRV MIRV, the second has been safely forgotten. Of course, the Blue Angels option has its drawbacks, one of which is the impossibility of dividing warheads, like the Bus option, up to 10-14, and theoretically up to 30 warheads. In the mid-80s, the Americans quite seriously assumed that there was a version of the Soviet SS-18 missile with thirty low-yield warheads (150 kt). Technically, the Blue Angels variant can be designed with no more than four individual targeting warheads. The main advantage of such a missile and the warhead disengagement method was the ability to actively maneuver throughout the flight, including the extra-atmospheric and atmospheric sections. In addition, there were opportunities for attacking targets along low-altitude flat trajectories (NT).
Back in 1988, the Lockheed company, commissioned by the Navy, carried out theoretical calculations of flat launch trajectories for the Trident-2 SLBM over short distances - two to three thousand kilometers for “soft” targets. Calculations were made according to the types of trajectories from NT-60 to NT-180 at a distance of 2000 kilometers and from NT-95 to NT-370 at 3000 (the index means the height of the apogee of the trajectory). The research results were partially published and the corresponding conclusion was made: firing a D-5 rocket at NT at short distances is possible even with a 40 percent reduction in flight time. But such an opportunity will come at a high cost. Since most of the rocket's flight along NT will take place in dense layers of the atmosphere, it is necessary to increase the platform acceleration speed from 6.5 to 8.7, and in some cases even to 9.2 kilometers per second. And this can only be done with a reduced number of warheads, that is, from one to three. At the same time, the accuracy of shooting is significantly deteriorating, the CEP increases by orders of magnitude - up to 6400 meters when firing at 2000 kilometers and 7700 meters - by 3000.
In terms of rational or optimal use of the cast weight, the Bus circuit looks better than the Blue Angels. In the latter, it is required to equip each warhead with an individual guidance system, its own remote control system, fuel and oxidizer tanks. In the absence of active means of defense in the supra-atmospheric space, the Blue Angels scheme was not that technically difficult or unrealizable, but unnecessary for that time. Actually, this is the only reason why the designers put it on the table half a century ago. Due to the physical principles on which the upper stage of the new missile is built, it is devoid of the drawbacks inherent in modern ICBMs and SLBMs with classical MIRVed missiles.
ICBMs based on SLBM technology
The domestic missile received its own formal name for international agreements RS-26 "Rubezh". In the West, according to the tradition that has developed over decades, it was assigned the SS-X-29 index. This name was given to the "Rubezh" by inheritance from the RS-24, after the "Yars" in NATO was named SS-27 Mod 2.
A draft design for a new rocket was prepared by the Moscow Institute of Heat Engineering (MIT). Full-scale development is underway between 2006 and 2009. In 2008, MIT and the Minsk Wheel Tractor Plant (MZKT) signed a contract for the preparation of the MZKT 79291 transporter for a mobile PU of the new complex. This wheeled conveyor is much smaller in size than the previous MZKT 79221, created specifically for Topol-M and Yars, and has a slightly lower carrying capacity - 50 tons versus 80. It is not difficult to calculate the starting weight of the new rocket: it should not exceed 32 tons. As for the dimensions of the transport and launch container: if there are no special restrictions on the diameter, then its length should not exceed 13 meters. Apparently, it was the dimensions of the new missile, and not the range of test launches, that caused the American side to worry about Russia's compliance with the treaty on intermediate and short-range missiles (INF). Some experts have suggested that a new small-sized ICBM is being developed in the Russian Federation on the basis of the Speed project, which was closed in 1991. It was the range of test launches that drew attention to the foreign media.
Since the beginning of the tests, the rocket has passed four flight tests. The first two - from the start at the Plesetsk cosmodrome on the target at the Kura test site. The second pair - October 24, 2012 and June 6, 2013 - from the start at the Kapustin Yar training ground against the target at the Sary-Shagan training ground. In the first case, the launch range is 5800 kilometers, in the second - just over 2000 kilometers. Perhaps these were test launches along a flat trajectory in order to check the characteristics of the rocket. There is no need to specifically create an IRBM and thus unilaterally withdraw from the INF Treaty, if any task set by the IRBM can be performed by an ICBM. Let us remind you that the minimum launch range for the RSD-10 (SS-20) is 600 kilometers, for the Topol (SS-25) - 1000 kilometers.
Ballistic missiles use solid fuels of two classes - 1.1 and 1.3. The energy content of fuel type 1.1 is higher than 1.3, so that for a given launch and throw weight, the missile launch range in the first case will be greater. Fuel of class 1.1 also has better technological properties, increased mechanical strength, resistance to cracking and grain formation. Thus, it is less susceptible to accidental ignition. At the same time, 1.1 fuel is more prone to detonation and is close to conventional explosives in sensitivity. Since the safety requirements in the terms of reference for ICBMs are much stricter than those for SLBMs, the former use class 1.3 fuel (Minuteman and Topol). In SLBM - 1.1 ("Trident-2" and "Bulava").
Most likely, MIT completed a new ICBM based on SLBM technologies. The rocket is not intended for installation in a mine (silo), only a mobile version was developed. As a result, the terms of reference did not impose requirements on it for increased shock resistance, since there is no need to withstand the shock load on a silo with a missile at close nuclear explosions, like the MX, Minuteman or SS-24 missiles, which were developed in two versions - mobile (BZHRK) and mine. Excessive weight of "Topol" is also a consequence of the two-way basing.
This is the same unified ICBM and SLBM missile based on Bulava, promised a few years ago. There are the first two steps from it, the third one consists of three separate steps of a smaller diameter (up to 0.8 m), connected in a package that fits into the common midship of the Bulava, two meters long. More than 3, 6 meters should not be in order for the improved ICBM to fit into a standard transport and launch container. They may be packaged in a single carbon fiber fairing, although this is not necessary at all. Suffice it to recall the SS-20 missile. Even for SLBMs, this is an optional condition (let's look at the R-27U). Probably, each stage is equipped with a 3D39 liquid-propellant engine powered by high-boiling fuel components. Fuel - dimethylhydrazine (heptyl, UDMH), oxidizing agent - nitrogen tetroxide.
Previously, this engine was used as a remote control unit for the R-29 RM SLBM breeding unit, having proven itself well. It is he who has all the necessary characteristics and will fit into the midsection of 0.8 meters. In general, it should be noted that liquid-propellant rocket engines have a number of undeniable advantages over solid-propellant (solid propellant rocket engines). This is, first of all, the possibility of multiple switching on, changing the amount of thrust in a wide range, and roll control. The most famous SLBMs - "Trident-1" and "Trident-2" in the area of operation of the first and second stages are not controlled by roll at all. Control takes place only in two planes in pitch and yaw. The third stage is already engaged in correcting the errors accumulated in the roll over the first 120 seconds of the flight, which makes a turn to the required angle.
The active section of the rocket should be lengthened up to the entry into the dense layers of the atmosphere up to 25-27 minutes. But this does not mean that the main engine of the third combat stage is running all the time. Only for a short time will the orientation engines be turned on to give the impulse necessary to evade GBI and SM-3 anti-missile missiles at altitudes ranging from 300 to 100 kilometers. The evolution of the warhead in the plane perpendicular to the velocity vector, in any case, even at very small values, will lead to the disruption of the anti-missile guidance. When entering the dense layers of the atmosphere from about 80 kilometers and below, the combat stage is no longer controlled by shunting rocket engines, but by aerodynamic surfaces - stabilizers. It is from this height that active braking of the RV BR with large values of negative accelerations occurs. In a short time - less than a minute - the speed of the warhead drops from seven to less than three kilometers per second. Therefore, it would be nice to briefly turn on the remote control for additional acceleration in order to go beyond the maximum operating modes of the second-tier air defense system THAAD.
The new complex from the end of this year will begin to enter the troops only in a mobile version. The 7th Guards from Vypolzov and the 29th Guards Irkutsk divisions will definitely receive it instead of the old Topol. From 2020, the rearmament of the 13th Dombarovskaya and 62nd Uzhurskaya divisions will begin with the new RC RS-28 "Sarmat" (SS-X-30). In total, it is planned to deploy at least 50 new ICBMs.
According to Western experts, the Russian group will consist of a little less than 250 ICBM launchers, of which only 78 launchers with monoblock missiles. The rest of the launchers will receive three new types of ICBMs - RS-24, RS-26 and RS-28, equipped with MIRVs. Old Soviet intercontinental missiles will be history by that time. In turn, the United States plans to leave in service 400 retirement age Minuteman ICBM launchers with monoblock warheads by 2040.