Chennai, Aug 28: The successful testing of scramjet, or air breathing engine, by India on Sunday is a baby step in space transportation and would take more than a decade to have such an engine to power a full-fledged rocket, said a senior official of Indian space agency.
"This is a baby step for us. It will take more than a decade to develop an engine to power a rocket. Currently no other country flies its rocket powered by a scramjet engine," K.Sivan, Director, Vikram Sarabhai Space Centre (VSSC) told reporters here on Sunday.
He said the testing of the scramjet engine is part of India's Make in India programme and Indian Space Research Organisation (ISRO) has developed several technologies like a reusable launch vehicle and others as a part of this scheme.
On Sunday morning, the ISRO test-fired its scramjet engine fixed atop its high-powered sounding rocket RH-560. The rocket flew from the rocket port at Sriharikota at 6 a.m.
Sivan said that the entire mission lasted just 300 seconds.
Queried about the use of scramjet engine in ISRO's rockets carrying satellites, he said several steps have to be taken before that.
"The engine that was tested today (Sunday) was burnt only for five seconds. But in a rocket, the engine has to burn for over 1,000 seconds. The speed at which it has to burn would also vary. We have to conduct various tests for that before getting ready an engine that can fly a rocket," Sivan said.
He said currently Indian rockets carry a huge quantity of oxygen - say 200 tons in a geosynchronous satellite launch vehicle (GSLV)- which gets burnt during the atmospheric flight phase of the rocket.
"The scramjet engine will suck the atmospheric oxygen and use that to burn the fuel. As a result the weight of the rocket will come down drastically which in turn can be used to increase the rocket's carrying capacity. The cost of rocket will also come down," Sivan said.
According to him, the total cost of developing this technology is estimated at Rs 35 crore.
He said the scramjet engine can be used to augment ISRO's reusable launch vehicle.
As a part of testing the technology ISRO tested two scramjet engines that were hugging the sounding rocket.
Sivan said: "With this flight, critical technologies such as ignition of air breathing engines at supersonic speed, holding the flame at supersonic speed, air intake mechanism and fuel injection systems have been successfully demonstrated."
The scramjet engine designed by ISRO uses hydrogen as fuel and the oxygen from the atmospheric air as the oxidiser.
The test flight was the maiden short duration experimental test of ISRO's scramjet engine with a hypersonic flight at Mach 6.
ISRO's Advanced Technology Vehicle (ATV), which is an advanced sounding rocket, was the solid rocket booster used for testing the air breathing engine.
The rocket weighed 3,277 kg at lift-off.
According to ISRO, some of the technological challenges handled by ISRO during the development of scramjet engine include the design and development of hypersonic engine air intake, the supersonic combustor, development of materials withstanding very high temperatures, 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.
"India is the fourth country to demonstrate the flight testing of scramjet engine. The successful technology demonstration of air-breathing scramjet engines in flight by ISRO today is a modest yet important milestone in its endeavour to design and develop advanced air breathing engines including engines for ISRO's future space transportation system," ISRO said in a statement.
