Rockets or Launch Vehicles:

Every flight into space begins with a rocket launching. The rocket can lift a satellite or spaceship  carrying human beings and equipment into space. Therefore,  it is also called launch vehicle. The rocket has been known to mankind  for centuries. Rockets used as firecrackers are a common sight on festive occasions  in our country. But the rockets that launch space whicles use highly advanced technology, and, of course, they are far more  

When  the  fuel  in the rocket is set tofire, a stream of hot gases is expelled at a high speed from its rear end (Fig).  As  ireaction to  the thrust of  the,gases,  the rocket moves in the opposite direction. As  long as the  fuel  in the rocket burns, shooting out gases, the rocket continues to accelerate forward, and acquires great speed. No single  rocket fired  from the earth can attain in one go the high speeneeded  to orbit the earth, or to escape its pull. Higher speeds are  reached by using big and small rockets, in stages. in the launch vehicle. As  the large rocket soars into space and uses up its fuel, lt IS separated from the smaller  rocket and drops off. The smaller  rocket already going at high speed is  then fired to accelerate  it to an even higher speed. Three-stage rockets are usually able to achieve speeds suitable for most purposes in  space (Fig). The final stage of  the launch vehicle carries the payload. Activity Verify the principle of  rocket motion by  releasing an inflated  balloon with its neck open. The different kinds of  payloads that rockets carry into space include artificial  satellites and space probes to nearby heavenly bodies. The satellites and probes themselves carry communication and research Quipment.