Engineers at ISRO are gearing up to test the scramjet engine developed in-house to power the Reusable Launch Vehicle (RLV) due to undergo the first experimental flight shortly. The scramjet engine which uses air breathing propulsion technology for hypersonic flight is scheduled to be test flown in January or February. The scramjet engine would be strapped to a two-stage Rohini sounding rocket for the experimental flight lasting seven seconds. It will be released at a height of 70 km and ignited during the coasting phase.

Space research organisations across the world are involved in the development of scramjet technology because it contributes to smaller launch vehicles with more payload capacity and promises cheaper access to outer space. While conventional rocket engines need to carry both fuel and oxidiser on board for combustion to produce thrust, scramjets obtain oxygen from the atmosphere by compressing the incoming air before combustion at supersonic speed.

Named Advanced Technology Vehicle (ATV), the test platform will comprise a scramjet engine hitched to a two-stage sounding rocket (RH- 560).