D-Propulse lines up a 2027 flight test for its rotating detonation engine after DRDO ground runs

D-Propulse, a Delhi based defence deeptech startup, is building rotating detonation engines for high speed drones and missiles. Instead of burning fuel in a steady flame like a conventional jet engine, a rotating detonation engine sends a supersonic detonation wave around a ring shaped chamber, compressing and igniting fresh fuel and air as it goes. The pitch is a smaller, simpler engine with fewer moving parts. Founder Saurav Jha told Inc42 and Mint that the design is 15 to 25% more efficient than today's jet engines, ramjets or scramjets, a figure that comes from the company.

The company was founded in July 2025 by Jha, a defence analyst who runs the Delhi Defence Review think tank, and Dr V Ramanujachari, a former DRDO scientist who led the scramjet engine programme and worked on the Akash missile's propulsion. It began as an IIT Madras incubated startup, ThePrint reports. In January 2026 it raised Rs 25 Cr from IAN Alpha Fund, which IAN Group said would go into engineers, simulation capacity and limited testing infrastructure. Former DRDO chairman V K Saraswat was named chief mentor at the time, and ThePrint reports he joined as board chairman in June 2026.

Its main milestone so far came on July 21 and 22, 2026, when it ground tested a 5 kN air breathing engine with an integrated aerospike nozzle at DRDO's Defence Research and Development Laboratory in Hyderabad. The startup says the proof motor beat its projected thrust despite reduced airflow and completed five ground runs within 24 hours, and Mint quoted an expert describing the result as technology readiness level 5, meaning validated in near real conditions but not yet in use.

A new Inc42 profile published on October 31 sets out the road ahead: flight tests in 2027 and limited series production by 2028. Mint earlier reported a first flight test by December 2027 and military user trials by December 2029, with the Indian armed forces expected to be the main customer. D-Propulse has no revenue or clients yet and is exploring paid testing services as an early income stream. Jha's claim that its engines can be at least 60% cheaper than ramjets rests on projected manufacturing costs and has not been proven in production, as both Inc42 and ThePrint note.

The bet matters because India has struggled for decades to field an indigenous jet engine and still depends on foreign suppliers for engines, spares and upgrades. Rotating detonation engines are still experimental worldwide, with the US and China among those testing them and no air breathing version publicly deployed in an operational missile or aircraft, according to Mint.