The scramjet engines help reduce launch costs by cutting down on the amount of oxidiser which needs to be carried along with the fuel.

An ISRO official told Indian media that the two air-breathing engines hugging an Advanced Technology Vehicle rocket normally start breathing air when the rocket reaches a height of 11 kilometres.

The ISRO 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.”

ISRO further said in a statement that 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 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.