As per unconfirmed reports, DRDO is developing Endothermic fuels for hypersonic applications. can be used in Scramjet & Hypersonic Glide Vehicle. Usage of Endothermic fuel is one method for Actively Cooled Scramjet.

The basic idea is to use a heat exchanger to transfer heat from the parts that need to be cooled to a hydrocarbon fluid that starts out cold. when the fuel is used in this way, it grows hotter and eventually reaches a temperature that triggers endothermic chemical reactions such as dehydrogenation and cracking, in which hydrocarbons break into simpler units.

At that point, the fuel continues functioning as a heat sink but does not continue to climb in temperature. Rather, the absorbed heat chemically converts the starting compound to other, simpler hydrocarbon products that can be used as fuel for propulsion. Analogously, transferring energy to liquid water causes the water temperature to rise until it reaches the boiling point. The water can continue absorbing energy at that temperature, but the energy input does not cause a further temperature rise; it instead drives evaporation.

DRDO's Hypersonic Technology Demonstration Vehicle (HSTDV)

DRDO on 7 September 2020 successfully flight tested the hypersonic air-breathing scramjet technology with the flight test of Hypersonic Technology Demonstration Vehicle (HSTDV).
The hypersonic cruise vehicle was launched using a proven solid rocket motor, which took it to an altitude of 30 km, where the aerodynamic heat shields were separated at hypersonic Mach number. The cruise vehicle separated from the launch vehicle and the air intake opened as planned. The hypersonic combustion sustained and the cruise vehicle continued on its desired flight path at a velocity of six times the speed of sound, i.e., nearly 2 km/s for more than 20 s. The critical events like fuel injection and auto ignition of scramjet demonstrated technological maturity. The scramjet engine performed in a text book manner.

The parameters of launch and cruise vehicle, including scramjet engine was monitored by multiple tracking radars, electro-optical systems and Telemetry Stations. The scramjet engine worked at high dynamic pressure and at very high temperature. A Ship was also deployed in the Bay of Bengal to monitor the performance during the cruise phase of hypersonic vehicle.

All the performance parameters had indicated a resounding success of the mission.