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The article explains about the recent launch of a rocket using scramjet engine that was developed indigenously and its benefits.
- The flight demonstration of the hypersonic air-breathing dual mode ramjet engine, which uses atmospheric oxygen in a portion of its journey, is a major step for Indian Space Research Organisation (Isro) in its pursuit for a future space transportation system.
- An experimental mission to demonstrate supersonic combustion using atmospheric oxygen was conducted recently. It was the maiden experiment of Isro's Dual Mode Ramjet (DMRJ) engine, which uses hydrogen as fuel and air from the atmosphere as the oxidiser, at hypersonic conditions.
- The programme, along with another ongoing programme for developing a re-usable launch vehicle, would position the organisation as a major space fairing agency with technological competence to offer services for low-cost access to space in the long term.
- The programme will help the organisation to reduce the number of stages in the current multi-staged expendable launch vehicles to two stages. Most of the current launch vehicles are designed for one time use and are expensive.
- Further, their efficiency in terms of payload to lift-off mass is low. Current rocket technology offers little opportunity in this regard given that nearly 85 per cent of the lift-off mass is propellant.
- Technologies to reduce weight and cost of space craft
- There are ongoing worldwide efforts to reduce launch cost. In order to achieve low-cost access to space, the strategy has been to try and reduce propellant mass, reduce the rocket size to have a higher payload to lift-off mass ratio, and make the rocket re-usable.
- While the goal is development of a single-stage-to-orbit (SSTO) launch vehicle configuration, to finally make access to space a routine affair at comparatively lower cost than conventional expendable rockets, a fully rocket-powered SSTO is not feasible with existing material and propulsion technology.
- However, air breathing propulsion can largely improve the feasibility of a SSTO if the air breathing mode can be efficiently used on a very large flight Mach number range, for example from Mach 1.5 to Mach 12.
- There are uncertainties related to air breathing mode performance and the existing material technology puts a question mark on the real feasibility of such a SSTO launcher in the near future.
- It could be relatively easy to develop a two-stages-to-orbit (TSTO) launcher with an air breathing first stage.
- The key technology to enable the operation of two stage and finally the SSTO launch vehicle is air breathing propulsion which can operate over a wide Mach number regime.
- Besides, if the first stage of the TSTO is made re-usable, the cost of launching satellites will come down by a magnitude two.
- Isro's mission
- The mission objectives of the ATV-D02/DMRJ mission are to demonstrate supersonic ignition, sustain the flame for combustion, and evaluate integrated DMRJ engine performance at hypersonic flight conditions.
- The space organisation says that the technological challenges for the mission include:
- Hypersonic air intake geometry with high pressure recovery and better shock wave-boundary layer management;
- Design of supersonic combustor, which includes fuel injection and flame holding device;
- Performance and operability across wide range of flight speeds, which is the transition from ramjet to scramjet;
- Thermal management of engines;
- Computational tools to simulate hypersonic flow and arrive at optimum Mach number-dynamic pressure window;
- Thermo-structural tests of scramjet engines and ground test at higher Mach number conditions; among others.
- For Isro, the technology demonstration of hypersonic air breathing dual ramjet engines would lead to the design and development capability of advanced air breathing engines, including engines with variable geometry air intake for its future space transportation system.
- Other things about the launch:
- India is the fourth country to demonstrate the flight testing of scramjet engine.
- Scramjet engines in flight is an important milestone in ISRO’s endeavour towards its future space transportation system.
- The scramjet engine is used only during the atmospheric phase of the rocket’s flight.
- Scramjet engines will help bringing down launch cost by reducing the amount of oxidiser to be carried along with the fuel.
- Scramjet engines designed by ISRO uses hydrogen as fuel and the oxygen from the atmospheric air as the oxidiser.
The recent launch of a rocket using scramjet engine that was developed indigenously is a significant technological development in Indian space research. But, it will take many years before a commercial rocket powered by a scramjet engine takes to the sky as there are several challenges to be overcome. Discuss.
- Significance of using scramjet engine.
- Challenges to be overcome for commercial use of this technology.
- The way forward.