Why in News?

• The Indian Space Research Organisation (ISRO) has recently successfully conducted the hot test of Scramjet Engine, a type of Air Breathing Engine.

Highlights

• An air-breathing engine is an engine that takes in air from its surroundings in order to burn fuel.
• All practical air breathing engines are internal combustion engines that directly heat the air by burning fuel, with the resultant hot gases used for propulsion via a propulsive nozzle.
• A continuous stream of air flows through the air-breathing engine. The air is compressed, mixed with fuel, ignited and expelled as the exhaust gas.
• Thrust produced by a typical air-breathing engine is about eight times greater than its weight.
• The thrust results from the expulsion of the working gases from the exhaust nozzle.
• India is the fourth country to demonstrate the flight testing of a Scramjet Engine.
• Air Breathing Engine provides a technological key for low-cost space transportation system.
• The technology is an important step towards developing reusable launch vehicles.
• Basically, of the total launch vehicle mass, 86% is propellant mass in the launch vehicle. Out of that propellant, 70% is oxidiser.
• These engines can reduce nearly 70% of the propellent carried in the vehicles as these systems use atmospheric oxygen, which is available up to a height of 50km from the earth’s surface.