Submarine launched ballistic missile: mysterious "underwater Epee" ■ Li Bozhen, Wang Shiyun, Ma Yubin Submarine launched ballistic missile usually refers to the ballistic missile launched by submarine. It has the advantages of flexible launch platform, strong survival and penetration ability and so on. When its range is long enough, its warhead equivalent is large enough, its strike accuracy is high enough, and it can be used to strike strategic targets, it becomes a submarine launched strategic ballistic missile. Submarine launched strategic ballistic missiles are usually equipped with nuclear warheads. Their huge damage power and concealment constitute the secondary nuclear strike capability of all countries. Therefore, all countries attach great importance to the research and development of submarine launched ballistic missiles. Any country that has made key progress in this regard will attract the attention of the world. In August last year, the South Korean Navy held a handover and listing ceremony for the diesel electric submarine anchanghao shimayama, which attracted much attention from the outside world. One reason is that the boat is equipped with a 6-unit vertical launch system, which can launch submarine launched ballistic missiles made by South Korea. In October of the same year, another new submarine launched ballistic missile launched by North Korea also attracted much attention. So, what is the current development process of submarine launched ballistic missiles in various countries? What is its future development trend? See the interpretation. It is not easy to change from land-based launch to submarine launch The development history of submarine launched ballistic missile is relatively short. In 1955, the US Navy first launched the design and development of such missiles. In the 1960s, with the successful test firing of Polaris A1, submarine launched ballistic missiles appeared on the world military stage. During the cold war, submarine launched ballistic missiles became the heavyweight weapons developed by the two camps, and achieved a series of results. With the development of submarine R & D technology, submarine launched ballistic missile with high concealment and tactical abruptness has become an important part of underwater nuclear power. Compared with land-based nuclear force and air-based nuclear force, underwater nuclear force with submarine launched ballistic missile as its pillar has stronger concealment and survivability, which is one of the important reasons why it has become an index of secondary nuclear strike capability. After decades of development, less than ten countries have mastered the technology of such a heavyweight weapon. Why? In addition to political and economic factors, the main reason is that the relevant technical threshold is too high. The research and development of submarine launched missiles is very difficult. Judging from the research and development of countries around the world, many submarine launched missiles are developed from land-based missiles. It seems that it is only changing ground launch to water launch, but technicians have a lot of difficulties to break through. First, missiles should be miniaturized. The internal space of submarines is limited, especially most submarine launched ballistic missiles adopt vertical launch mode. Due to the diameter of the hull, the size of the missile can not be too large. Second, the underwater launch situation is complex. Whether it is wet launch, dry launch, hot launch or cold launch, we must deal with the relationship between launcher and missile, ignition timing and success rate. The missile has to pass through two media: water and air. How to reduce the resistance as much as possible, plan the trajectory in the water, and deal with the shallow water flow or surge on the sea surface have brought difficulties to the design. Third, the missile body should be strengthened and reinforced. Cold launch is the main launch mode of submarine launched ballistic missile at present. The missile has high exit speed and bears large overload and impact force, especially when operating in water. Only by strengthening and strengthening the missile body can it avoid deformation, rupture and leakage of the missile body. Especially in the special case of launching under ice, the reinforcement requirements of the projectile body will be higher. Fourth, the requirements for guidance are high. In order to ensure long-range strike effect, submarine launched ballistic missiles in various countries mostly adopt composite guidance mode. Not to mention the use of satellite guidance or starlight correction, even for inertial guidance systems, most countries do not have the ability to develop them. Fifth, composite materials are widely used. For strategic missiles, reducing structural mass and increasing missile range and power are consistent requirements. The application of composite materials can better meet this requirement. The three-stage engines of French M51 submarine launched ballistic missiles use composite materials. The first and second stage rocket engine shells of trident-2 submarine launched ballistic missile are also made of carbon fiber composites to reduce the mass of the missile. In addition, with the improvement of the defense capability of anti missile systems all over the world, the sea battle environment is more complex. Submarines carrying submarine launched ballistic missiles have to launch more in the fortress sea area, which puts forward higher requirements for the range and accuracy of missiles. On the other hand, as an important part of strategic deterrence, submarine launched ballistic missiles will not easily transfer and leak related technologies, which further increases the difficulty of submarine launched ballistic missile research and development. From missile R & D to matching launch platform, function improvement is like running a marathon Russian Dagong Vladimir submarine, which can launch multiple "Bulava" submarine launched ballistic missiles at the same time. The function of submarine launched ballistic missile is closely related not only to the technical performance of the missile itself, but also to the matching degree of the launch platform submarine. The launch environment of submarine launched ballistic missile is relatively complex, so the safety problems caused by missile falling after ejection or launch failure must be considered. At present, when submarine launched ballistic missiles are launched in various countries, they generally tilt out of the water. One of the purposes of this design is to prevent boat smashing. When developing Polaris A1, the United States did a lot of work before launching the missile with a real submarine, including underwater ejection scale model and full-scale model test, pool ejection tether test, offshore net support test, submarine fixed launch pad test, land and ship launch tube ejection model test The underwater launch tube ejects the model bomb equipped with a primary engine, and finally carries out the underwater launch missile test of the submarine. The purpose of launching this series of tests is to solve the problem of "matching missiles with submarines". This consideration is only one of the contents of matching submarine launched ballistic missiles with submarines. In fact, in the development process of submarine launched ballistic missile, it and submarine have been doing the multiple-choice question of "who will accommodate who". The Soviet Union's Golf class conventional power ballistic missile submarine is equipped with ss-n-5 missiles. Because the length of the launcher exceeds the diameter of the submarine pressure shell, the excess part is covered with the command platform enclosure, which makes the volume of the command platform enclosure of the submarine huge. Russia's "Bulava" submarine launched ballistic missile is developed from land-based "poplar" m missile. In order to adapt to the submarine platform, its bullet length is 9.5 meters shorter than that of "poplar" m, and the launch weight is also greatly reduced. Russian Brava submarine launched ballistic missile. In order to adapt to the launch environment of submarines, submarine launched ballistic missiles are relatively "short and fat" compared with their important technical source - land-based ballistic missiles. Reflected in the aspect ratio (the ratio of projectile length to diameter), the value is relatively small. The matching degree between the submarine and the missile affects the role of submarine launched ballistic missiles to a certain extent, and also more or less affects the deterrent effect of underwater nuclear forces in various countries. "Trident-2", "Brava" and French M51 submarine launched ballistic missiles, as important components of the nuclear forces of the United States, Russia and France, reflect the high level of submarine launched ballistic missile technology in the world in terms of technical performance. French M51 submarine launched ballistic missile. Us trident-2 submarine launched ballistic missile. Data picture The development of American "trident-2" submarine launched ballistic missile started earlier and its technology is relatively mature. "Bulava" is a new generation of Russian submarine launched ballistic missile. Using technologies such as rapid combustion boost and reducing the infrared characteristics of tail flame, it overcomes the shortcomings that it is easy to be detected by satellites and has strong penetration ability. In 2020, the success of four Russian "Bulava" volleys highlights its combat capability. The French submarine launched ballistic missile also started earlier. The M51 submarine launched ballistic missile in service adopts a high thrust engine, the shell is reinforced for the nuclear combat environment, and the miniaturized warhead can realize stable reentry. Like other weapons and equipment, the research and development of submarine launched ballistic missiles can not be done once and for all, but has been improving and upgrading. The competition among countries makes its function improve like running a marathon. With long-range missiles, we will then study ultra long-range and intercontinental missiles, and there are many models of short-range submarine launched ballistic missiles. In addition to the requirements for range and accuracy, the requirements for the number of launch tubes, the degree of silence of submarines and the comfort of living boats are also increasing. The first batch of anchanghao, shimayama, South Korea, has three groups of launch tubes with a total of 6 units. The second batch that has begun construction will be equipped with five groups of launch tubes with a total of 10 units. While maintaining their strike capability, some U.S. submarines began to reduce the number of launch tubes, and turned their attention to the living conditions on board, in order to obtain longer underwater navigation time. The development path is clear, and the future battlefield calls for stronger capabilities It is reported that at present, only the United States, Russia, Britain, France, China, India, North Korea and South Korea have mastered submarine launched ballistic missile technology. On the whole, the development path of submarine launched ballistic missiles is relatively clear in the future. Although submarine launched missiles must first meet certain sea conditions and have requirements for the size of waves, submarine speed and diving depth, under comprehensive consideration, submarine launched ballistic missiles are still the backbone of underwater nuclear forces. At present, the world's nuclear powers have deployed a large number of strategic nuclear warheads on ballistic missile nuclear submarines. Relevant data show that the rate of submarine based deployment of strategic offensive nuclear warheads in the United States and Russia has reached more than 60%, and this proportion is still increasing year by year; Britain announced in 1995 that it would deploy all its strategic nuclear warheads on nuclear submarines; France also deployed all its strategic nuclear forces on nuclear submarines at the end of the 20th century. From this point of view, in the future, submarine launched ballistic missiles will still be the top priority in the development of all countries. At present, the development trend of submarine launched ballistic missiles is mainly reflected in the following aspects: First, it has a larger range. The characteristics of submarines cruising around determine that it is difficult for the enemy to locate them. However, with the development of sensor technology, the possibility of submarine being detected increases. Today, when "discover and destroy" has become a reality, in order to make submarines move outside the opponent's attack range and increase the survival rate, it is necessary to increase the range of submarine launched ballistic missiles - try to complete the attack on enemy targets in the safe sea area under our control. The second is to shorten the flight time of the missile boost phase. At present, most of the anti missile defense systems established by various countries are aimed at intercepting missiles in the middle and end of flight, but at this stage, the missile flight speed is high and the interception effect is poor. In view of the relatively low flight speed of ballistic missiles in the boost phase, many countries began to plan to intercept enemy missiles in the boost phase. For submarine launched ballistic missiles, completing the boost phase flight in the shortest time and at the fastest speed has also become the key to the success or failure of their attack. Third, improve the attack efficiency of the warheads carried. In order to improve the strike efficiency of submarine launched ballistic missile, the designer gives it the ability of several air maneuvers and multi warhead separation. In the future, these capabilities will continue to rise with the improvement of the performance of the anti missile interception system. The reentry vehicle carrying the sub missile warhead to attack the target is equivalent to the "one foot at the door" when the submarine launched ballistic missile attacks. Improving its efficiency has become one of the most direct ways for countries to strengthen the underwater deterrence capability