Scramjet engine: Known for its many feats in the field of space and technology, ISRO (Indian Space Research Organisation) has made India proud again! ISRO has successfully test-fired its Scramjet Rocket Engine, a breakthrough technology in air-breathing propulsion. Usually, rocket engines carry both the fuel and the oxidiser on board for combustion. But with Scramjet engines using oxygen from the atmosphere, ISRO’s cost of missions would be greatly reduced. The Scramjet engine designed by ISRO uses Hydrogen as fuel.
What is air-breathing propulsion? Explains ISRO, air-breathing rocket systems use atmospheric oxygen from their surroundings, burn it with the stored onboard fuel to produce a forward thrust. This is in contrast to the conventional chemical rocket systems which carry both the oxygen and the fuel onboard. What this effectively helps in achieving is a lighter system. Says ISRO, “Air-Breathing systems become much lighter and more efficient leading to reduced overall costs.” According to ISRO, the development of a Scramjet system is extremely complex as it involves many technological challenges, especially relating to mixing of very high speed air (velocity around 1.5 km/s) with fuel, achieving stable ignition and flame holding in addition to ensuring efficient combustion, within the practical length of the combustor.
Some of the technological challenges handled by ISRO during the development of Scramjet engine include the design and development of hypersonic engine air intake, development of materials withstanding very high temperatures, supersonic combustor, computational tools to simulate hypersonic flow, ensuring performance and operability of the engine across a wide range of flight speeds, proper thermal management and ground testing of the engines.
Today, after a smooth countdown of 12 hours, the solid rocket booster carrying the scramjet engines, lifted off at 6:00 AM in the morning. In its release, ISRO said that important flight events, such as burn out of booster rocket stage, ignition of the second stage solid rocket, functioning of Scramjet engines for 5 seconds followed by burn out of the second stage took place exactly as planned. After a flight of 5 minutes, the vehicle touched down in the Bay of Bengal.
The development of this high-technology system will go a big way in meeting India’s futuristic space transportation needs. ISRO first achieved the technological breakthrough in the design, development, characterisation and realisation of the Supersonic Combustion Ramjet, or Scramjet, in 2006. ISRO is already known for its low-cost, yet path-breaking missions and technology such as Mars Orbitor Mission and its PSLVs. It recently launched a record twenty satellites in a single mission, 17 of which were foreign. India has become the fourth country to demonstrate the successful test flight of a Scramjet engine.