The major portion of weight in satellite launch vehicles is contributed by fuel. Thus, vehicles have to carry a large weight of fuel during their course of journey. Earlier Satellite Launch Vehicles (SLV) used to be of a single stage vehicles. Such SLVs used to be very heavy as well as expensive in terms of its fuel consumption.
To overcome this problem of launch vehicles carrying heavy load during its entire journey, it is provided with more than one stage. In multistage the weight of the vehicle can be reduced step by step, after its launching.
- In multistage SLVs, as the journey of the launch vehicle progresses and the vehicle achieves a specific velocity and a certain height, the fuel of the first stage is exhausted and the empty fuel tank gets detached from the main body of the launch vehicle and falls back into a sea or on unpopulated land.
- As the fuel in the first stage is exhausted, the engine in the next stage is ignited.
- However, the weight of the launch vehicle is now less than what it was earlier and hence it can move with higher velocity.
Thus, it saves fuel consumption. Hence, it is beneficial to use a multistage satellite launch vehicle