Final Answer:
The AIM-120 rocket motor's propulsion is prevented by the absence of a rocket motor. The AIM-120 utilizes a solid rocket motor for initial acceleration, but once the rocket motor burns out, the missile transitions to its sustainment phase, during which it relies on its air-breathing ramjet engine for propulsion.
Step-by-step explanation:
The AIM-120 Advanced Medium-Range Air-to-Air Missile (AMRAAM) employs a dual-mode propulsion system to optimize performance during different phases of its flight. In the initial phase, the rocket motor provides the necessary thrust for acceleration. However, once the rocket motor exhausts its propellant, it becomes non-propulsive. This is a crucial design feature to maximize the missile's range and effectiveness.
The sustainer phase follows the rocket motor phase, and this is where the AIM-120's air-breathing ramjet engine comes into play. Unlike traditional rocket motors, a ramjet engine relies on the intake of air from the atmosphere to support combustion. This air-breathing capability allows the missile to achieve sustained high-speed flight over a more extended range compared to rocket-only systems. The transition from rocket motor to ramjet engine contributes to the AIM-120's versatility and effectiveness in engaging targets at varying distances.
In conclusion, the AIM-120 missile is equipped with a propulsion system that strategically combines a rocket motor for initial acceleration and an air-breathing ramjet engine for sustained flight. This dual-mode propulsion design enhances the missile's overall performance and adaptability in engaging aerial threats.