India successfully tested an indigenously developed hypersonic technology demonstrator vehicle (HSTDV) powered by a scramjet engine, which will serve as a critical building block for the next-generation hypersonic cruise missiles capable of flying at speeds above Mach 5. The HSTDV test, conducted from the Dr Abdul Kalam Island off the Odisha coast at 11.03 am to demonstrate the autonomous flight of a scramjet integrated vehicle, propelled India right into an extremely exclusive hypersonic club consisting of the US, Russia and China.
Besides the velocity of over five times the speed of sound (Mach 5), the manoeuvring capability of hypersonic missiles makes them very effective offensive weapons capable of defeating enemy missile defence and tracking systems. The US, Russia and China are leagues ahead in the race to develop aerodynamically manoeuverable hypersonic weapons. China, in fact, flaunted its DF-17 missile with a hypersonic glide vehicle at its national military parade last year.
In the Indian test on Monday, the hypersonic ‘cruise vehicle sustained its scramjet-powered flight path at a velocity of six times the speed of sound (Mach 6, or nearly 2 km per second) for 22-24 seconds. It auto-ignited to fly on its own after separating from the ‘launch vehicle’, which took it to an altitude of 30 km. The launch vehicle, in turn, was powered by the proven solid-propellant rocket motor of an Agni ballistic missile.
“It’s a major technological breakthrough. The airbreathing scramjet engine was successfully flight tested at hypersonic speed within the atmosphere, meeting all technical parameters. The test paves the way for development of many more critical technologies, materials and hypersonic vehicles,” DRDO chairman Dr G Satheesh Reddy said.
Congratulating DRDO, PM Narendra Modi tweeted, “The scramjet engine developed by our scientists helped achieve a speed of 6 times the speed of sound. Very few countries have such capability today.” Defence minister Rajnath Singh said it was a “landmark achievement” towards ‘Atmanirbhar Bharat’. It was now time to progress to the next phase with all “critical technologies” being established by the successful HSTDV flight test, using the indigenously developed scramjet propulsion system, he added.
The next phase will be to develop long-range hypersonic cruise missiles, which DRDO scientists said would be possible in five to six years. The complex technology behind the HSTDV, the maiden launch of which had failed in June last year, also has civilian applications like low-cost launch of small satellites. India still has to achieve sustained scramjet-powered hypersonic flight for a few minutes, which has been repeatedly demonstrated by the US, Russia and China.
The Indian armed forces already have the ramjet-powered BrahMos supersonic cruise missiles, which fly at Mach 2.8 speed, developed jointly with Russia. Their strike range is being enhanced from the original 290 km to well over 400 km. A scramjet engine is an improvement over the ramjet engine because the former operates efficiently at hypersonic speeds and allows supersonic combustion using hydrogen fuel. Ramjets, in contrast, operate well at supersonic speeds around Mach 3 but their efficiency drops at hypersonic speeds.
