DRDO successfully tests Hypersonic Technology Demonstrator Vehicle

News: Prime Minister has congratulated Defence Research and Development Organisation(DRDO) for the successful flight of Hypersonic Test Demonstration Vehicle(HSTDV).


  • HSTDV: It is an unmanned scramjet demonstration aircraft for hypersonic speed flight. 
  • Working: 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.
  • Purpose: 
    • It can be used as a carrier vehicle for hypersonic and long-range cruise missiles.
    • It has multiple civilian applications including missiles of the future for air defence, surveillance besides in the development of energy-efficient, low cost and reusable satellite-launch vehicles.
  • Developed by: It has been developed by the Indian Defence Research and Development Organisation(DRDO).
  • Significance: India has become the fourth country after the United States, Russia and China to develop and successfully test hypersonic technology.

Additional Facts:


  • Ramjet: It 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. 
  • Working: 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.
  • Drawback: 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.


  • Scramjet: It 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.