History Of Liquid Propellant Rocket

Rocket engines are one of the most difficult and complex machinery made by mankind. The first working liquid-fueled rocket engine was developed by an american scientist Dr Robert Hutchings Goddard in 1926, that rocket traveled 45 feet during 2.5 second.


The rocket consists of two tanks, one is oxidizer tank and another one is fuel tank. The fuel and oxidizer are separately stored in these two tanks. They are in the form of liquid the combination of the fuel and oxidizer are called propellant. In liquid propellant rockets the fuel and oxidizer are in the form of liquids, so these rockets are called liquid propellant rockets. 

Turbo Pump

Couple of turbo pumps were used for pumping oxidizer and fuel to the combustion chamber.

Combustion Chamber

The fuel and oxidizer mixture are burning inside the combustion chamber.

Read Also: Sea Dragon: The Biggest Rocket Ever Designed

Fuel Injector

It convert liquid fuel and oxidizer mixture into small droplets and spray inside the combustion chamber.


With the help of electrical signal it generates spark and burn the propellant.


Nozzle is used for expand and accelerate the combustion gas.


Now, let's see the working principle of the rocket.

With the help of turbo pumps, the fuel and oxidizer are pumped into the injector. The injector convert the liquid propellant into small droplet and spray into the combustion chamber. The flow of the injector are controllable even we can increase or decrease the flow amount of the propellant with the help of electrical signal. The igniter generates sparks due to the ignition the combustion takes place when combustion takes place in combustion chamber. Very high pressure and high temperature gases are produced. The highly heated products of combustion gases are then allowed to expand in the nozzle section. In the nozzle pressure, energy of gas is converted into kinetic energy. So these gases are coming out with very high velocity. Due to the gases coming out with very high velocity from the nozzle, a force or thrust will produce in opposite direction. This thrust propels the rocket or the rocket will move forward.

Read Also: Do You Know: How The First Spy Satellites Worked?

Advantages Of Liquid Propellant Rocket

Let's see what are the advantages of liquid propellant rocket.

  • The combustion process are controllable, it can be increase or decrease.
  • The flow of the propellant speed regulation is possible.
  • It is more economical for long range operations.
  • The accidents can be rectified at any stage.

Disadvantages Of Liquid Propellant Rocket

Let's see what are the disadvantages of the rocket:

  • They are more complicated in construction.
  • The manufacturing cost is high.
  • The size and weight of the engine is more comparing with solid propellant rocket.

Why oxidizers are stored inside the rocket?

Most type of burning in engines on earth use oxygen that is easily available on the earth atmosphere but in the space there is no atmosphere to provide oxygen or other oxidizer so rocket need to carry their own oxidizers.