At the dsei-2021 International Defense Exhibition held in the UK not long ago, Diehl systems of Germany introduced an air-to-air missile concept with stealth design. This air-to-air missile is a rectangular body, which applies the ultra long edge strip and wing body fusion technology, reflecting the development trend of air-to-air missile to stealth in the future. In September this year, a weapon concept called long-range air-to-air missile (lraam) was unveiled at the annual meeting of the US Air Force Association. With its unique front and rear two-stage structure layout, this missile has aroused speculation about its range. Before and after that, Russia demonstrated the new r-37m hypersonic air-to-air missile mounted on the Su-35 fighter. As an improved version of the r-37 missile with a range of 400 km, the r-37m has a longer range and shows a diversified development trend of carrier aircraft. Why have countries around the world repeatedly introduced new air-to-air missile concepts? What is the positioning and development of air-to-air missiles in air combat? See the expert interpretation. MiG-31 fighter that launches r-37m air-to-air missiles. The evolution of air-to-air missiles ■ Zhang Huishang Hongbo After more than 70 years of rapid development, air-to-air missiles have become the main weapon to seize air control in modern war The world's first air-to-air missile was the x-4 air-to-air missile developed by Germany at the end of World War II. The missile is launched by aircraft, using radio command guidance and solid rocket motor. These technologies were high-tech at that time, but they could not be used in actual combat because of their immature technology. After World War II, air-to-air missiles developed rapidly and equipped the army in the mid-1950s, forming the first generation of air-to-air missile family. The typical products of this generation of infrared guided air-to-air missiles include the aim-9b "rattlesnake" of the United States and the K-13 of the Soviet Union. They all use uncooled lead sulfide infrared detectors and ultra-small electron tube amplifiers for signal processing. They can only be detected behind the tail of the target, and the effective attack range is only 2 ~ 3 kilometers behind the tail of the target. This generation of radar guided air-to-air missiles is mainly semi-active radar guidance. Typical products such as American "sparrow" - 1 adopt radar beam guidance and have a small attack range. Therefore, the first generation air-to-air missile can only be used as an auxiliary weapon of machine gun. The representative products of the second generation of Infrared Air-to-Air Missiles include the American aim-9d "rattlesnake", the French "Matra" r550 and the Soviet r-60t. They were equipped with the army in the 1960s. The cooled lead sulfide detector was used to improve the sensitivity, and the transistor circuit was used for signal processing. While reducing the weight, the reliability and service life of the missile were improved. The infrared proximity fuze was used. Typical radar guided air-to-air missiles include American "sparrow" - 3a and British "firelight", which adopt rotating wing aerodynamic layout and continuous wave semi-active radar guidance. The attack envelope of this kind of missile has been expanded, but it can only attack in the rear hemisphere or intercept small maneuvering targets head-on. Aim-9x air-to-air missile. In the 1960s, American aircraft designers and air force decision makers believed that missiles determine everything, "take-off search lock launch missile disengage" will become the basic mode of air combat. Therefore, the second-generation jet fighters of the US air force, such as the F-105 "Lei Gong" and the F-4C "ghost", were not equipped with air guns at first and used missiles as air combat weapons. As a result, they were "slapped in the face" by reality. During the Vietnam War, the U.S. air-to-air missile hit rate was very low, and the "sparrow" - 3 launched 589, only 55 hit. The rattlesnake also lost its end after launch. In front of the MIG aircraft dominated by air guns and supplemented by missiles in the Vietnamese air force, the US aircraft equipped with only air-to-air missiles was once hit and had to reinstall air guns. The typical products of the Third Generation Infrared Air-to-Air Missiles include American aim-9l "rattlesnake" and Israeli "strange snake" - 3, which began to equip troops in the early 1980s. This generation of Infrared Air-to-Air Missile uses gyro rudder as tilt stabilization device, uses InSb cooling detector with higher sensitivity, and uses laser or radio proximity fuze to realize omni-directional attack. Although the forward attack distance is only 2km ~ 3km, the lateral attack ability is greatly improved. In the 1990s, improved Infrared Air-to-Air Missiles came out one after another, such as American aim-9m "rattlesnake" and Russian R-73. With the support of digital processing technology, laser proximity fuze or radio fuze, they not only realize omni-directional attack on the target, but also have certain anti-interference ability. The third generation radar guided air-to-air missiles include Russian r-27, American sparrow-3b, British Sky flash, etc. they adopt single pulse semi-active radar seeker, which has forward interception capability, certain anti-jamming capability and down looking and down shooting capability. The performance of air-to-air missile in this period can basically meet the requirements of over the horizon air combat. In 1982, Israel launched a large-scale land air coordinated raid to destroy the surface to air missile positions deployed by Syria in the Bekaa Valley. In the two-day air battle, the Israeli air force launched 56 aim-9l and 3 aim-9p air-to-air missiles and shot down 41 enemy fighters, with a hit rate of 69%. Since then, the air combat mode has entered the high-tech era and turned a new page in the history of world air combat. The typical products of the Fourth Generation Infrared Air-to-Air Missile include aim-9x of the United States, asraam of Britain, IRIS-T of Germany, and "strange snake" - 4 / 5 of Israel. This kind of missile adopts technologies such as infrared imaging detection, post launch interception and thrust vector control. The tracking, mobility and anti-interference are greatly improved, the launch mode is more flexible, and the attack envelope is greatly expanded. The fourth generation radar air-to-air missiles include American aim-120, European "meteor", Russian R-77, etc. This kind of missile usually has a conventional aerodynamic layout and adopts compound guidance methods such as midway command, inertial guidance and radar active terminal guidance. The embedded computer is equipped with powerful software, which can carry out over the horizon omni-directional attack. It has a variety of anti-jamming measures and flexible launch methods, which can realize "no matter after launch" and effectively intercept a variety of aircraft. In 1994, a NATO warplane patrolling Bosnia and Herzegovina launched three air-to-air missiles within four minutes and shot down three fry G-4 attack aircraft, setting a record of "killing three people with one aircraft". Asraam air-to-air missile. Long, fast, accurate and flexible, the strong support of key technologies helps the leapfrog development of air-to-air missiles Weapon development is inseparable from scientific and technological support. Looking at the more advanced air-to-air missiles in various countries in the world, they usually have the following technical characteristics: The range is getting farther and farther. With the rapid development of airborne radar and battlefield early warning reconnaissance system, the perception ability of fighters and unmanned aerial vehicles has been greatly extended. In addition, the IFF system is becoming more and more mature, and over the horizon air combat has become an important mode of confrontation. In order to find, launch and destroy the enemy first, all countries put forward higher requirements for the range of air-to-air missiles. In recent years, the number of medium range, medium long range and long-range air-to-air missile projects in the United States is much more than that of short-range combat air-to-air missile projects, and even puts forward requirements for over the horizon attack on small advanced capability missile (sacm) projects. The aim-120d extended range projectile of the United States has a range of 160 km and is still actively developing aim-260 with an expected range of twice its range to achieve the so-called "penetrating air control". The meteor jointly developed by six European countries is the world's first air-to-air missile using solid rocket ramjet, with a maximum range of 150 km. The Russian k-77m uses an enhanced dual pulse engine with a range of nearly 200 kilometers. The range of the k-37m is said to be 300 km ~ 400 km. Su-35 fighter with R-77 air-to-air missile. Faster and faster. The fourth generation fighters generally have supersonic cruise and high mobility. In order to effectively strike such targets, it is necessary to have a faster flight speed than the target. At present, the maximum flight speed of air-to-air missiles can reach more than five times the speed of sound. Russian Su-35 fighters will be equipped with a new type of r-37m hypersonic air-to-air missile, the Russian news reported. The missile is mainly used to attack large targets, such as enemy bombers, early warning aircraft, tankers, etc. the maximum speed can exceed 6 times the sound speed. After launching, the missile does not need to continuously illuminate the target with airborne radar. The missile flies with the help of inertial automatic guidance according to the parameters. After approaching the target, the active radar guidance head is turned on, and the target is locked to launch an attack. Facing the high speed of r-37m exceeding Mach 6, once the fighter is locked, it is almost impossible to escape. A Typhoon fighter that launches IRIS-T air-to-air missiles. The accuracy is getting higher and higher. Limited by size and weight, the warhead of air-to-air missile is only thousands of grams to tens of kilograms, and the effective killing radius is usually only a few meters to more than ten meters. At the same time, all kinds of artificial photoelectric and electronic interference and background interference such as sun, cloud, rain, fog and ground / sea clutter will affect the detection, locking and tracking of air-to-air missiles. In order to destroy the target, the missile must have high guidance accuracy and anti-jamming ability. The first mock exam technology is difficult to meet the operational requirements. Therefore, the new generation of air-to-air missiles mostly use multi-mode guidance technology to improve the hit accuracy. The multi-mode seeker can be composed of different kinds of detection systems (infrared, radar, laser, etc.), the same kind of different wave band detection systems or the same kind of different systems (active radar, semi-active radar, passive radar). Common multimode seeker includes optical dual (multi) band seeker, active radar / infrared dual-mode seeker, active / passive radar composite seeker and so on. The launch mode is becoming more and more flexible. Due to the high-speed movement of launch platform and target, the air combat situation changes rapidly. In order to gain an advantage in battle, air-to-air missiles must be launched in a flexible way. The first generation air-to-air missile has high requirements for the battle position of the carrier aircraft, and it is difficult to capture good launch opportunities in actual combat; The second generation air-to-air missile improves its flexibility and can attack in a large range from the tail of the target; The third generation air-to-air missile technology is becoming more and more mature, with all-altitude, all-round and all-weather combat capability; The fourth generation air-to-air missiles have realized "discovery and launch", and air combat has really entered the era of beyond visual range. At present, air-to-air missiles all over the world regard "omnidirectional launch" as an important development index, that is, the missile can be launched backward, attack the target behind the carrier, or realize "over shoulder launch". Python (strange snake) air-to-air missile. Small, networked, multi-purpose, cross domain and intelligent, air-to-air missiles can be expected in the future Miniaturization. In order to meet the requirements of high-density embedded mounting of the fourth generation stealth fighter and improve the combat effectiveness of the carrier, there is a strong demand for miniaturized air-to-air missiles. In addition, with the emergence of cooperative operation between UAV and UAV and UAV swarm operation mode, UAVs that go deep into the enemy's depth to implement assault also need to carry small air-to-air missiles. From the development of foreign military equipment, after the missile interception technology is gradually mature, the miniaturized interceptor will become an important air combat weapon of the next generation of fighter. This small interceptor does not occupy the aircraft hanging point and launches micro interceptors. It mainly intercepts incoming air-to-air missiles or surface to air missiles. It is estimated that its weight is 10kg ~ 15kg and its length is within 1m ~ 1.5m. It can be launched from the existing chaff and infrared decoy projectile dispensers. Networking. With the improvement of network information system, modern air combat has also changed from early platform confrontation to network-based system confrontation. Air to air missiles need to be deeply integrated with the whole combat system, have the ability of network information acquisition and network guidance, and make comprehensive use of ground radar, airborne radar, early warning aircraft and even space-based satellites to obtain target information,