The Defence Research and Development Organisation (DRDO) successfully launched the indigenously-developed Hypersonic Technology Demonstrator Vehicle (HSTDV) in its maiden test on June 12. The HSTDV was test-fired by  from Launch Complex-4 of the Integrated Test Range (ITR) on Abdul Kalam Island in the Bay of Bengal at 11.27am, the Defence Ministry said in a statement. 

It said the DRDO launched the technology demonstrator vehicle to prove a number of critical technologies for futuristic missions. “The missile was successfully launched. Various radars, telemetry stations and electro-optical tracking sensors tracked the vehicle through its course. The data has been collected and will be analysed to validate the critical technologies,” it said.

What are the features of HSTDV?

The HSTDV is an unmanned scramjet demonstration aircraft for hypersonic speed flight, it can cruise at a speed of mach 6 and move up to an altitude of 32.5 km (20 miles) in 20 seconds.

Besides its utility for long-range cruise missiles of the future, the dual-use technology will have multiple civilian applications also. It can be used for launching satellites at low cost, experts said.

Describing the maiden trial of the HSTDV as successful, a DRDO scientist said, “The new technology demonstrator vehicle was tested and the observations made by the radars and tracking sensors showed that it was a success.”

The trial was carried out in the presence of senior scientists and defence officials, including DRDO chairman G. Satheesh Reddy and ITR director B.K. Das.

The HSTDV can move up to an altitude of 32.5 km in 20 seconds and once it is achieved successfully, India will enter a select club of countries that have such technology. 

“The HSTDV project, through which we want to demonstrate the performance of a scramjet engine at a low altitude of 15 to 20 km, was on for a couple of years. Under this project, we are developing a hypersonic vehicle to be powered by a scramjet engine,” a DRDO scientist associated with the programme said.

The initial trial seeks to validate the aerodynamics of the air vehicle as well as its thermal properties and scramjet engine performance.

The HSTDV cruise vehicle is mounted on a solid rocket motor, which will take it to a required altitude, and once it attains certain mach numbers for speed, the cruise vehicle will be ejected out of the launch vehicle. Subsequently, the scramjet engine will be ignited automatically. 

What is Scramjet?

Ramjet, Scramjet and Dual Mode Ramjet (DMRJ) are the three concepts of air-breathing engines which are being developed by various space agencies. 

A ramjet is a form of air-breathing jet engine that uses the vehicle’s forward motion to compress incoming air for combustion without a rotating compressor. Fuel is injected in the combustion chamber where it mixes with the hot compressed air and ignites. A ramjet-powered vehicle requires an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust.

Ramjets work most efficiently at supersonic speeds around Mach 3 (three times the speed of sound) and can operate up to speeds of Mach 6. However, the ramjet efficiency starts to drop when the vehicle reaches hypersonic speeds.

A scramjet engine is an improvement over the ramjet engine as it efficiently operates at hypersonic speeds and allows supersonic combustion. Thus it is known as Supersonic Combustion Ramjet, or Scramjet. 

A dual mode ramjet (DMRJ) is a type of jet engine where a ramjet transforms into scramjet over Mach 4-8 range, which means it can efficiently operate both in subsonic and supersonic combustor modes.