DRDO’s HEMRL Indigenises Signal Star Naval Flare for Kalvari-Class Submarines

Pune, August 29, 2025 — In a landmark advancement under India’s Atmanirbhar Bharat initiative, the Defence Research and Development Organisation’s High Energy Materials Research Laboratory (HEMRL) has successfully developed and handed over the indigenous Signal Star Naval Flare—a state-of-the-art underwater pyrotechnic signalling system designed for the Indian Navy’s Kalvari-class submarines.

At a formal ceremony held in Pune, the Director of HEMRL handed over the system to Rear Admiral Rupak Barua, Director General of Naval Armament Inspection (DG-NAI), marking its official induction into the Navy’s underwater warfare suite.

Operational Capabilities & Design Features

• Deployment & Activation
  The Signal Star Naval Flare is launched from a submarine’s signal ejector and rises through the water column. Upon surfacing, a hydrostatic mechanism triggers ignition, releasing a high-intensity, star-like illumination visible over extended distances. This ensures effective signalling in adverse weather and night operations.

• Dual-Colour Signalling
  The system provides two distinct colour options:

  • Red: Used in distress, emergencies, or urgent tactical communication.

  • Green: Used for identification, recognition, or safe-operational communication, particularly useful during coordinated fleet manoeuvres.

• Robust Engineering
  Encased in a pressure-resistant housing, the flare is designed to withstand the immense hydrostatic pressures of deep-sea operations. It offers long shelf-life, durability, and consistent performance in harsh marine environments—reflecting India’s growing expertise in pyrotechnics, material sciences, and structural design.

Strategic and Operational Significance

• Enhanced Safety & Communication
  The flare boosts the operational readiness of Kalvari-class submarines, ensuring secure communication with surface vessels and aircraft. It also provides emergency location marking, fleet training support, and safe surfacing during joint missions.

• Wartime & Peacetime Utility
  Beyond tactical wartime use, the system is vital in rescue operations, fleet coordination, and peacetime exercises, making it a versatile tool for naval operations.

• Reducing Import Dependency
  With this indigenous development, India no longer relies on foreign suppliers for this critical submarine system, closing a major gap in naval logistics and strengthening strategic autonomy.

Context: Kalvari-Class Submarines

The Kalvari-class (Project-75) submarines, built in India with technology transfer from France’s Naval Group and Mazagon Dock Shipbuilders Limited (MDL), are among the most advanced conventional diesel-electric submarines in service. They are designed for anti-surface warfare, anti-submarine warfare, intelligence gathering, minelaying, and surveillance, forming the backbone of India’s conventional underwater fleet.

A Milestone in Self-Reliance

The successful induction of the Signal Star Naval Flare demonstrates India’s growing capabilities in naval warfare technology and defence manufacturing self-reliance. By replacing imports with an indigenous solution, the system strengthens India’s defence preparedness and supports the long-term strategic vision of Atmanirbhar Bharat.

Officials associated with the project emphasised that the achievement not only enhances the operational strength of the Indian Navy but also establishes India’s credibility in an area long dominated by advanced foreign suppliers.