In the above photo, an unmanned boat is equipped with a fixed launch system and carries two AIM-9 "Sidewinder" series infrared guided air-to-air missiles. The appearance of this type of air-to-air missile on unmanned boats has indeed attracted a lot of attention. The AIM-9 air-to-air missile is a short-range infrared guided air-to-air missile developed by the United States in the 1950s, nicknamed the "Sidewinder". It is also one of the world's largest and most widely used air-to-air missiles in practical applications. The two missiles in the photo are the export model AIM-9P air-to-air missiles of the AIM-9 Sidewinder, which have appeared multiple times in regional conflicts in recent years. In the case of ammunition shortage, this type of air-to-air missile is often used as a guest ship to air missile. At the beginning of design, tactical missiles have clear exclusive combat purposes. Missiles with different combat purposes have significant differences in their technical and operational indicators, but in some cases, they can still "guest star" in other roles. Many missiles have played "guest appearances" before. The Israeli "Spike" - NLOS anti tank missile can "guest star" long-range precision shells, while the US "Standard-6" air defense missile can "guest star" supersonic anti-ship missiles and land attack missiles. Generally speaking, in emergency situations, missile "guest appearances" can solve urgent problems and even play a role in turning the tide of the war. However, the "guest appearance" of missiles requires certain conditions. Combat personnel must have a thorough understanding of the performance of the missiles used in order to achieve flexible application. In addition, after the change of missile launch platform, it is necessary to solve the adaptation problems of launch environment and guidance system. When the missile makes a guest appearance, both the launch environment and the combat environment have changed, some of which directly affect the performance of the missile. For example, air-to-air missiles were originally launched from high-speed and stable fighter jets, but now they are launched from low-speed platforms on the swaying and salt spray eroded sea surface, which poses new challenges to the missile's launch equipment, initial attitude adjustment, and other aspects. The launched air-to-air missile needs to track low altitude flying targets in the background of sea clutter, which also poses new requirements for the missile's guidance head and anti-interference capability. In recent years, missile "guest appearances" have become a common practice among warring parties in regional conflicts. Behind it is not only a change in the launch platform, but also a reflection of the trend of modern warfare towards integration, low cost, and decentralization. In the future, more missiles may embark on the path of "guest appearances". (Looking into the New Era)