DRDO Successfully Demonstrates SFDR Technology

• 05 Feb 2026

Source: TH 

Why in News?  

The Defence Research and Development Organisation (DRDO) has successfully carried out a flight demonstration of Solid Fuel Ducted Ramjet (SFDR) technology from the Integrated Test Range (ITR), Chandipur, Odisha. 

• With this successful test, India joins an elite group of nations possessing SFDR technology, which is critical for developing long-range air-to-air missiles.

What is  Solid Fuel Ducted Ramjet (SFDR) Technology?

• SFDR: It is a cutting-edge missile propulsion technology. Unlike conventional rockets that carry both fuel and oxidiser, SFDR is an "air-breathing" engine that uses atmospheric oxygen to burn solid fuel, allowing for sustained supersonic speeds and extended ranges. 
• Working of SFDR: 
  • Nozzle-less Booster: This component accelerates the missile to supersonic speeds within three seconds, a prerequisite for the ramjet to function. 
  • Ducted Ramjet Sustainer: Once at speed, a boron-based solid fuel ignites. It draws oxygen from the atmosphere (saving weight by not carrying an oxidizer) to fuel combustion, allowing powered flight for 50 to 200 seconds. 
  • Hot Gas Valve: Developed using carbon-carbon composites and tungsten-copper alloys, this valve regulates combustion gases based on altitude and speed. 
  • Cheek-Mounted Air Intakes: These efficiently compress incoming air to ensure sustained combustion during flight. 
• Key Performance Metrics:  
  • Altitude Flexibility: The missile can operate from sea level up to an altitude of 20 km. 
  • High Manoeuvrability: It is capable of executing vertical manoeuvres of up to 10 km. 
  • Precision Targeting: Integrated with radio-frequency seekers, inertial navigation, and jam-resistant data links to ensure high accuracy. 
  • Sustained Supersonic Speeds: Unlike standard solid-fuel rockets that burn out quickly, SFDR sustain speeds between Mach 2 and Mach 3.8 for longer durations. 
  • Extended Range: It enables fighter jets to engage targets far beyond visual range, with an operational range between 50 km and 340 km. 
  • Lethality: It is designed to carry a fragmentation warhead with a proximity fuse to maximize damage against fast-moving aerial targets. 
• Significance:  
  • Larger No-Escape Zone: By maintaining speed and energy until the terminal phase, it creates a wider "no-escape zone," making it significantly harder for enemy aircraft to evade. 
  • Operational Versatility: The technology can be adapted for both air-to-air and surface-to-air missile systems, enhancing broader air defence capabilities. 
  • Strategic Boost: This technology is the backbone of India’s upcoming Astra Mk-3, a Beyond Visual Range Air-to-Air Missile (BVRAAM) intended to rival the European Meteor missile and the Chinese PL-15. 
  • Tactical Edge: It provides the Indian Air Force (IAF) with a "First Look, First Kill" capability, allowing them to engage adversaries from safe standoff distances.

Ramjet, SFDR, and Scramjet Technologies

Feature	Ramjet	SFDR (Solid Fuel Ducted Ramjet)	Scramjet (Supersonic Combustion Ramjet)
Combustion	Subsonic (Air slows down inside engine)	Subsonic (Air slows down inside engine)	Supersonic (Air flows fast inside engine)
Fuel Type	Liquid Fuel (mostly)	Solid Fuel (Boron-based)	Liquid Hydrogen
Oxidizer	Atmospheric Oxygen	Atmospheric Oxygen	Atmospheric Oxygen
Primary Use	Cruise Missiles (e.g., BrahMos)	Air-to-Air Missiles (e.g., Astra Mk3)	Hypersonic Vehicles (e.g., Hypersonic Technology Demonstrator Vehicle (HSTDV))

Frequently Asked Questions (FAQs) 

1. What is Solid Fuel Ducted Ramjet (SFDR) technology?
SFDR is anair-breathing missile propulsion system that uses atmospheric oxygen to burn solid fuel, enabling sustained supersonic speeds and longer range. 

2. Why is SFDR technology important for India?
It enableslong-range air-to-air missiles, improves the no-escape zone, and places India among a select group of advanced missile-capable nations. 

3. How is SFDR different from conventional solid rocket motors?
Unlike rockets that burn out quickly,SFDR provides sustained thrust by continuously burning fuel using atmospheric oxygen. 

4. Which upcoming missile system will use SFDR technology?
SFDR is thebackbone of Astra Mk-3, a Beyond Visual Range Air-to-Air Missile (BVRAAM) under development by India. 

UPSC Civil Services Examination, Previous Year Questions (PYQs) 

Q. Consider the following statements:

1. Ballistic missiles are jet-propelled at subsonic speeds throughout their flights, while cruise missiles are rocket-powered only in the initial phase of flight.
2. Agni-V is a medium-range supersonic cruise missile, while BrahMos is a solid-fuelled intercontinental ballistic missile.

Which of the statements given above is/are correct?

(a) 1 only 

(b) 2 only 

(c) Both 1 and 2 

(d) Neither 1 nor 2 

Ans: d

Q. With reference to Agni-IV Missile, which of the following statements is/are correct? (2014)

1. It is a surface-to-surface missile. 
2. It is fuelled by liquid propellant only. 
3. It can deliver one-tonne nuclear warheads about 7500 km away. 

Select the correct answer using the code given below: 

(a) 1 only 
(b) 2 and 3 only 
(c) 1 and 3 only 
(d) 1, 2 and 3 

Ans: (a)