Illustrative
India's burgeoning defence start-up ecosystem has notched up a significant milestone with D-Propulse successfully testing its rotating detonation engine (RDE).
Co-founded by propulsion expert Sourav Jha and eminent scientist Dr V. Ramanujachari, the venture boasts mentorship from Dr V.K. Saraswat, former DRDO chief and NITI Aayog member. This breakthrough underscores India's push towards indigenous hypersonic and advanced propulsion technologies.
Rotating detonation engines represent a paradigm shift in aerospace propulsion. Unlike conventional engines that rely on deflagration—subsonic combustion—RDEs harness continuous detonation waves travelling supersonically around an annular combustor. This process yields higher thermodynamic efficiency, potentially slashing fuel consumption by up to 25 per cent while delivering compact, high-thrust outputs ideal for missiles, ramjets, and even space launch vehicles.
D-Propulse's recent test featured a 5 kN combustor, with footage revealing stable detonation waves sustaining high-pressure combustion. The trial validates the startup's design prowess in managing the extreme instabilities inherent to RDE operation, such as wave mode transitions and thermal management. Such success positions D-Propulse at the forefront of India's efforts to master detonation-based propulsion, critical for next-generation hypersonic cruise missiles and air-breathing scramjets.
Sourav Jha, a seasoned aerospace engineer with prior stints at leading firms, brings hands-on expertise in solid and liquid propulsion systems. Dr V. Ramanujachari, renowned for his contributions to ISRO's liquid engines and Agni missile stages, lends unparalleled credibility.
Dr V.K. Saraswat's guidance, drawing from his oversight of hypersonic technology at DRDO, ensures alignment with national strategic goals like the Hypersonic Technology Demonstrator Vehicle (HSTDV) program.
The test arrives amid heightened global competition in RDE development. The United States' DARPA and NASA's programmes have logged subscale tests exceeding 2,000 seconds of operation. Russia claims operational RDE integration in the 3M22 Zircon hypersonic missile. China, too, advances via its WS-15 engine derivatives. India's D-Propulse entry narrows this gap, leveraging private-sector agility to complement DRDO's foundational work on detonation ramjets.
Prime Tooling, another nimble start-up, parallels D-Propulse's ambitions by targeting RDEs specifically for missile applications. Though details remain sparse, their focus on compact, high-impulse thrusters aligns with demands for loitering munitions, BrahMos-II hypersonics, and swarm drone propulsion. This dual-track private innovation signals a maturing ecosystem, where start-ups like these accelerate timelines beyond traditional PSUs such as HAL or BEL.
RDE technology holds transformative potential for Indian defence. In missiles, it enables sustained Mach 5+ speeds with reduced size and weight, enhancing standoff strike capabilities against adversaries like Pakistan's HQ-9 or China's DF-17. For space, RDEs could power reusable upper stages, cutting PSLV/GSLV costs and bolstering Gaganyaan's orbital manoeuvres. Efficiency gains also promise greener aviation, aligning with India's net-zero aviation goals by 2070.
Challenges persist, however. Stabilising detonation waves demands advanced materials like ceramic matrix composites to withstand 3,000 K temperatures. Injector designs must ensure uniform fuel-air mixing amid chaotic flows. D-Propulse's 5 kN scale-up from lab prototypes addresses these, but full-system integration—pairing RDE with inlets and nozzles—remains the next hurdle. Computational fluid dynamics and AI-driven simulations, likely employed here, will prove pivotal.
Government backing amplifies these efforts. The iDEX scheme and Technology Development Fund channel funds to start-ups, fostering dual-use tech. Recent ₹10,000 crore allocations for private defence R&D, coupled with Atmanirbhar Bharat, create fertile ground. D-Propulse's test, possibly under DRDO collaboration, exemplifies this synergy, mirroring successes like Skyroot's Vikram-S rocket.
Looking ahead, scaling to 50-100 kN thrusts beckons for air-launched hypersonics. Integration with DRDO's solid rocket motors or liquid boosters could yield hybrid systems for Agni-VI or Nirbhay upgrades. Prime Tooling's missile-centric path might yield tactical RDEs for Nag or Akash-NG variants, diversifying threats.
This dual start-up surge reflects India's strategic pivot: from importer to innovator in propulsion. As hypersonic arms races intensify, D-Propulse and Prime Tooling embody the private sector's role in securing technological sovereignty. Their RDE tests herald a new era, where detonation waves propel India onto the global stage.
IDN (With Agency Inputs)
