India’s Defence& Research Development Organisation (DRDO), on 7 September, tested a Hypersonic Test Demonstrator Vehicle (HSTDV) that zipped at 2km per second, or six times the speed of sound, demonstrating an air-breathing engine envisioned for future civilian and military applications. The hypersonic cruise vehicle launched on a proven solid-fuelled rocket from Wheeler Island off the Odisha coast, which ferried it to an altitude of 30km. The rocket flew along an intended flight path over the Bay of Bengal at 2km per second for 20 seconds.
The HSTDV performed on all parameters, including combustion chamber pressure, air intake and control guidance. “The engine performed in a textbook manner,” the DRDO said in a media release. The successful flight of the Hypersonic Technology Demonstrator Vehicle involved multiple critical technologies such as hypersonic manoeuvres, air-breathing propulsion and high temperature materials, among others.
With the test, India became the fourth country after the United States, Russia and China to develop and successfully test hypersonic technology. This test means that the DRDO will have the capacity to develop a hypersonic missile with scramjet engine in next five years, which will have the capacity to travel at more than two kilometres per second.
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Hypersonic flying vehicles have potential applications in weapons-delivery systems such as missiles with extended range and in futuristic spaceplanes for low-cost satellite launches.
The DRDO had attempted a technology demonstrator flight, in June 2019, but the test had failed as the launch rocket itself did not reach the desired altitude.
There, the cruise vehicle separated from the rocket, began to “breathe” air, activated onboard ignition and achieved sustained combustion — driven by oxygen from air and a reservoir of hydrocarbon fuel — to fly at six times the speed of sound.
Hypersonic flying vehicles are delivery platforms capable of both manoeuvring and flying faster than five times the speed of sound.
These two features — manoeuverability and speed — enable hypersonic missiles to penetrate most missile defences, compressing the timelines for a response by a nation under attack.
A key advantage of air-breathing engines is that they do not need to carry fuel and an oxidiser as do all conventional rockets. The engine uses oxygen from the air inflight. This means a lower launch weight — a feature that can also be used to extend the range of missiles.
Scientists believe hypersonic vehicles could also find use in spaceplanes for which conceptual studies have been under way in India for more than two decades. The long-term goal would be a reusable spaceplane — a vehicle that can return for repeated launches — that would help lower the cost of launching satellites.
Significance of the test
The DRDO said in a series of tweets, “In a historic mission today, India successfully flight tested Hypersonic Technology Demonstrator Vehicle, a giant leap in indigenous defence technologies and significant milestone towards a Sashakt Bharat and Atmanirbhar Bharat. DRDO with this mission, has demonstrated capabilities for highly complex technology that will serve as the building block for NextGen Hypersonic vehicles in partnership with industry.”
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In the test which was conducted, on 7 September, the Agni missile was used. A solid rocket motor of Agni missile was used to take to an altitude of 30 kilometers where the cruise vehicle separated from the launch vehicle and the air intake opened as planned. The parameters of the test were monitored by multiple tracking radars, electro-optical systems and telemetry stations and a ship was also deployed in the Bay of Bengal to monitor the performance during the cruise phase of hypersonic vehicle.
A senior DRDO scientist said that though the system was tested for a very short duration, it has given scientists a large set of data points to work on for further development. The indegenous development of the technology will also boost the development of the systems built with hypersonic vehicles at its core, including both offensive and defensive hypersonic cruise missile systems and also in the space sector.
Scientists believe that while the successful test is a major milestone, many more rounds of tests will have to be done to achieve the level of technology with countries like the US, Russia and China.
About Scramjets
The scramjets are a variant of a category of jet engines called the air breathing engines. The ability of engines to handle airflows of speeds in multiples of speed of sound, gives it a capability of operating at those speeds.
Hypersonic speeds are those which are five times or more than the speed of sound. The unit tested by the DRDO can achieve up to six times the speed of sound or Mach 6, which is well over 7000 kilometers per hour or around two kilometers per second.
For the test, the hypersonic combustion sustained and the cruise vehicle continued on its desired flight path at a velocity of Mach 6 for a period of 20 seconds. “The critical events like fuel injection and auto ignition of scramjet demonstrated technological maturity. The scramjet engine performed in a text book manner.” The DRDO said. While the technology helps achieve hypersonic speeds, it comes with its set of disadvantages, and the obvious one being its very high cost and high thrust-to-weight ratio.
Development of the Technology
The DRDO started on the development of the engine in early 2010s. The Indian Space Research Organisation (ISRO) has also worked on the development of the technology and has successfully tested a system in 2016. DRDO too has conducted a test of this system in June 2019.
The special project of the DRDO consisted of contributions from its multiple facilities including the Pune headquartered Armament and Combat Engineering Cluster. At the hypersonic speeds, the system has tohandle temperatures to the range of 2500 degrees Celsius as well as the air speed, and thus development of the material is one of the main challenges.
DRDO Offers Free Access to Patents to Start-ups, SMEs
The Defence Research and Development Organization (DRDO) has opened up its huge pool of intellectual property by offering 1,500 patents to entrepreneurs free of cost.
“To give a big boost for defence manufacturing in the country, the DRDO is offering 1,500 of its patents, including critical missile technology, life sciences, and naval technology for free to entrepreneurs that might want to build products,” said G Satheesh Reddy, Chairman of DRDO.
He was delivering the special address at the inaugural of the two-day webinar on ‘Invest in Telangana: Opportunities in Post Covid World’ on 27 August.
