ET-LDHCM Hypersonic Missile Hits Milestone: DRDO’s Scramjet Tech Nears Flight Tests in 2026

On November 22, 2025, the Defence Research and Development Organisation (DRDO) successfully completed the final ground-test series of the indigenous scramjet engine for the External-Tank-Launched Dual-role Hypersonic Cruise Missile (ET-LDHCM) at the Hypersonic Propulsion Test Facility, Hyderabad. The engine sustained stable combustion at Mach 6.5 for over 180 seconds — a world-class performance that clears the path for captive carriage trials on Su-30MKI in mid-2026.

What is ET-LDHCM?

ET-LDHCM (pronounced “Etaldakam”) is India’s first air-breathing hypersonic cruise missile designed to be launched from the external fuel tank position of the Su-30MKI. Once released at 12–14 km altitude and Mach 1.2, the missile jettisons the tank fairing, ignites its scramjet, and accelerates to Mach 6–7 for the cruise phase, delivering a 500–800 kg warhead to 1,200–1,500 km range.

Because it uses atmospheric oxygen instead of carrying oxidiser, the missile is dramatically lighter than traditional boost-glide hypersonics like Russia’s Zircon or China’s DF-17, enabling a single Su-30MKI to carry two missiles without sacrificing combat radius.

Technical Breakthroughs Achieved in 2025

November’s ground tests validated:
– Fuel-cooled composite airframe surviving 1,800 °C surface temperatures
– Stable combustion of kerosene-based fuel in scramjet at Mach 6.5 simulated conditions
– Active cooling of thermal management system using onboard fuel as coolant
– Seamless transition from booster to scramjet mode in <4 seconds

The scramjet combustor, made of niobium-alloy and ceramic-matrix composites developed by DMRL Hyderabad, recorded zero flame-outs across 42 runs — a reliability figure that matches or exceeds global leaders.

Strategic Rationale

ET-LDHCM directly addresses two pressing threats:
1. Chinese carrier battle groups operating 1,500 km from India’s coast
2. Time-critical, heavily defended targets in depth (e.g., Three Gorges-type infrastructure)

At Mach 7, the missile covers 2 km every second — giving adversaries less than 10 minutes reaction time from launch to impact and rendering even S-400/S-500 batteries largely ineffective due to extreme kinematic performance and plasma-sheath stealth.

Related reading: DRDO’s ‘Jishnu’ Miniature Missile Debut: Tactical to Strategic Hypersonic Evolution

Production & Industrial Partners

Bharat Dynamics Limited (BDL) has been designated lead integrator. Subsystems are distributed as:
– Scramjet engine → GTRE Bengaluru
– Airframe & thermal protection → DRDL Hyderabad + MIDHANI
– Seeker → RCI Hyderabad
– Booster → Premier Explosives

An initial production order for 120 missiles is expected by 2028, with unit cost projected at ₹70–90 crore — significantly lower than imported equivalents.

Future Roadmap

• 2026 → Captive flight + booster separation trials
• 2027 → Full-profile flight with live scramjet burn
• 2028 → Anti-ship variant (sea-skimming terminal phase)
• 2030 → Submarine-launched canister version (VLS from Project 75-Alpha SSNs)

DRDO has also begun concept studies for a Mach 8+ follow-on using hydrogen fuel under the classified “Project Agni-H” banner.

Conclusion

With ET-LDHCM, India is not just joining the hypersonic club — it is doing so with an air-breathing, carrier-killer weapon that no other nation has operationally fielded from tactical aircraft. When the first Su-30MKI releases this missile over the Bay of Bengal in 2026, it will mark the moment India transitions from hypersonic demonstrator (HSTDV) to deployable strategic weapon system.

In the words of DRDO Chairman Dr. Samir V. Kamat at the November 22 press briefing:
“Speed is the new stealth. And very soon, India will own the fastest shadow in the sky.”

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• DRDO’s ‘Jishnu’ Miniature Missile: Tactical Hypersonic Pathway
• Astra’s Extended Reach & Su-30MKI Hypersonic Roadmap