What are the disadvantages of a missile

The rocket

Generally

The rocket is a missile that carries all the means necessary to generate its thrust energy and does not depend on the presence of an atmosphere (see recoil principle). It essentially consists of the engine and fuel cells. The cells supply the engine with the necessary fuel, which burns it and ejects it through a nozzle (red), thus providing an opposite thrust that moves the rocket forward (blue).

Recoil principle

Mass particles (the burned fuel) (red) flow out of the nozzle of an engine. Since, according to Newton, a reaction (the outflow) is followed by a counter-reaction, an opposing force acts on the rocket (the recoil) (blue). It is precisely this force that moves the rocket forward.

This principle works independently of an atmosphere, which means that a rocket can also maneuver in space.

Drive types

Only the two most common types of drive are presented here: that Liquid rocket engine and the Solid rocket engine.

  • Liquid rocket engine

    With such an engine, the actual fuel (1) (Alcohol, kerosene, hydrogen ...) and an oxidizer (2) (Oxygen) stored separately. The oxidizer is necessary to make the fuel burn. Both components are usually strongly cooled in order to bring them into liquid form in order to increase the amount carried.

    After opening the valves, the two components are pumped using centrifugal pumps (3) produced by a turbine (5) via a gas generator (4) are driven into the combustion chamber (6) pumped.

    Before combustion, the fuel or the oxidizer are often conducted in lines over the nozzle and over the combustion chamber (turquoise) in order to cool it and prevent it from melting. These are heated at the same time.

    Fuel and oxidizer are injected into the combustion chamber (6), they ignite (purple) as soon as they come into contact with each other (self-reacting fuels) or are triggered by a flame generator (7) (similar to a spark plug in a car) ignited. The mixture expands suddenly as a result of the explosion. It then flows through the nozzle (8) out.

    The faster the outflow speed, the higher the increase in speed of the rocket (see recoil principle).

    The liquid rocket engine is used in most rockets (e.g. Saturn, Soyuz, Ariane, Space Shuttle in some cases) because the combustion can be interrupted and reactivated. The disadvantage is the complex technology (centrifugal pumps, cooling, separate cells) that is required for this.

  • Solid rocket engine

    With these engines, the fuel is carried in solid form. The solid contains the actual fuel and an oxidizer in chemical form.

    The ignition is carried out once by an ignition cartridge or an electric igniter (9). Then gradually the solid ignites (10) and flows through the nozzle (8) from (purple).

    The disadvantage of these engines is that once ignited, they cannot be stopped. The advantage is in the easier-to-use technology. No complex cooling mechanisms and pumps are required.

    Solid propellants are used, for example, in the two boosters of the space shuttle, which provide the take-off thrust.

control

Controlling a rocket during launch is difficult because it is subjected to very large forces during the launch phase. Since rockets usually consist of several engines, you can add more or less fuel to a nozzle by regulating the fuel pumps. This results in different outflow velocities (asymmetry of the thrust force) at the nozzles, which steers the rocket in a different direction.
The control in space takes place by means of small thrusters, which serve as a recoil by emitting small amounts of fuel and maneuver the rocket accordingly.

The Apollo capsule, for example, has a number of maneuver nozzles with which it can maneuver in all spatial axes.

Multi-stage missiles

This type of rocket consists of several rocket stages (each consisting of fuel cells and engine), which are separated one after the other as soon as their fuel supply is exhausted. This reduces the mass of the rocket and allows higher speeds and thus higher orbits to be achieved.
The Saturn V, for example, consists of 3 rocket stages.