Space Shuttle Regular exploration, frequent visits o astronauts into space and increasing costs made it necessary to develop a re-usable space craft which could be sent, into space, complete it’s mission and return to Earth and then be re-used. As a result of developmental work in this area, the first space shuttle, called ‘Columbia’ was launched into space by the United States of America in April 1981. The space shuttle resembles...

Rockets A rocket like a jet engine burns fuel to produce hot gases which it releases from the rear thus giving it the thrust to fly up into the air. However rockets are different from jet engines, since rockets fly up to high altitudes where no oxygen is present in the air, they have to carry their own supply of oxygen. On the other hand jet engines in aeroplanes draw the...

Jet Planes To fly, an aircraft has to first lift itself off the ground, this lift is produced by the movement of air under the aircraft’s wings, since they are slightly curved. As the thrust to move forward comes from the plane’s jet engines, which push the aeroplane forward by blowing compressed hot gas backwards, the plane moves forward to take off and the air flowing under the wings lifts the...

Helicopters   Though unusual the helicopter is a useful aircraft. Since they can vertically take off and land in a very limited space, turn in any direction very quickly and hover in air, helicopters can be put to many uses. They have been successfully used for passenger, mail or goods’ transportation, or for prospecting, aerial photography, sea and land rescue work, crop spraying and a host of other purposes. A helicopter...

Submarines   A submarine is a ship capable of moving underwater and is used either for exploration or by the Navy for defensive or offensive purposes. Most modern submarines are powered by nuclear reactors, which produce heat, the water vapour from this heat causes the turbines to rotate thus giving mechanical energy to the propeller shafts and electric generators, this drive provides the required propulsion. These craft are equipped with a...

Hovercraft and Hydrofoils The hovercraft is a unique vehicle capable of running both on land and water. The hovercraft generates an air cushion on it’s underside with the help of turbo electric engines. The operating principle is very simple, air is taken in and compressed, it is then pushed under the hovercraft. A skirt made of rubber surrounds the underside of the craft thus preventing the air from escaping from the sides....

Ships and Ocean Liners   There are various types of ships which include ‘Cargo Carriers’ for carrying various types of cargo in the holds or on the deck in containers, .Oil Tankers’ for carrying oil, ‘Naval Battleships’ for defence and ‘Aircraft Carriers’ which carry aeroplanes for the Navy. There are also the ‘Ocean Liners’ which are large ships used for transporting people at sea. Ships of all types may be built...

Electric Locomotives The first Electric locomotives were run on batteries but modern day electric locomotives draw their power from over head wires or a third rail which runs parallel to the tracks. Electric locomotives have an arm on the top called the ‘pantograph’, when raised, this arm touches a high voltage un-insulated wire which runs overhead. The power drawn from this wire powers the electric motors in the engine thus allowing...