India’s “Iron Dome”? S-400 “Sudarshan Chakra” Air Defence System in Action

By Candlelight in Chandigarh: India’s S-400 “Sudarshan Chakra” Air Defence System in Action

By Candlelight in Chandigarh: India’s S-400 “Sudarshan Chakra” Air Defence System Keeps us Safe

Chandigarh. 8th May 2025. As we sit in this historic city gripped by a mandatory blackout, an eerie quiet blankets the streets—interrupted only by the low, ominous wail of sirens and the stuttering hum of overworked generators. In gated colonies and high-rise apartments, RWA WhatsApp groups erupt in fury, chastising the negligent “offenders” whose windows still betray slivers of light. The night feels tense, charged, as though the city itself holds its breath. I write this by candlelight—a humble yet defiant gesture of continuity in a time of crisis. Above us, an invisible shield keeps watch. The S-400 "Sudarshan Chakra" air defence system, recently baptized in real combat, now stands as the guardian of our skies—not just a foreign acquisition, but a critical pillar of India’s national defence.

A Titan of Air Defence: Core Components of the S-400

The S-400 Triumf, designated "Sudarshan Chakra" in Indian service, is not an indigenous development. It is a state-of-the-art, Russian-made, long-range surface-to-air missile (SAM) system designed by Almaz-Antey. India signed a $5.4 billion contract with Russia on October 5, 2018, for the procurement of five such systems.

The S-400 operates through an interlinked suite of six major components:

• 91N6E “Big Bird” Radar: A long-range surveillance radar capable of detecting over 300 airborne targets within a 600 km radius.

• 92N6E “Gravestone” Radar: A fire-control radar that guides missiles towards selected targets within a 400 km range.

• 55K6E Command Center: A mobile command post that fuses sensor data, prioritizes threats, and controls launch sequences.

• 5P85TE2/SE2 Launchers: Mobile missile platforms capable of carrying 4 to 12 missiles each.

• Multi-Layered Missile Arsenal: Includes short-, medium-, long-, and ultra-long-range missiles for adaptive interception.

• 40V6MR Radar: An optional tower-mounted radar for enhanced low-altitude threat detection, such as terrain-hugging cruise missiles.

Operational Workflow: From Detection to Destruction

The S-400’s functioning unfolds in a structured five-step workflow:

1. Detection

Detection begins with the Big Bird radar, which continuously scans for threats such as aircraft, drones, and incoming missiles. It uses IFF (Identification Friend or Foe) technology to differentiate between friendly and hostile objects. To counter low-flying threats, the 40V6MR radar or secondary systems are engaged.

2. Target Prioritization

Threat data is processed at the command center, which uses real-time analytics to rank threats based on velocity, altitude, direction, and potential damage. It can engage up to 36 targets simultaneously, covering multiple altitude bands.

3. Missile Launch

The system employs a multi-tiered arsenal designed to intercept targets based on type, distance, and threat level:

• The 40N6 missile, with a range of up to 400 km, is deployed against high-value strategic targets such as AWACS (Airborne Warning and Control Systems) and aerial refueling tankers.

• The 48N6DM missile, with a 250 km range, is used to neutralize ballistic missiles and high-speed aircraft.

• The 9M96E and 9M96E2 missiles, effective within 120 km, are intended for fighter jets and drones.

• Short-range missiles, with a range of up to 40 km, are employed against low-flying cruise missiles and UAVs.

Typically, two missiles are fired per target to maximize interception reliability.

4. Guidance and Interception

Once airborne, missiles are guided via active radar homing or inertial navigation, with mid-course updates from the Gravestone radar. Upon nearing the target, proximity-fused warheads detonate to maximize destruction.

5. Mobility and Reload

After launch, mobile launchers follow “shoot-and-scoot” tactics, relocating within 5 minutes to avoid enemy retaliation. The system can restart operations within 35 seconds from standby mode.

Strategic and Technological Edge

The S-400 is equipped with key features that ensure its supremacy in layered air defence:

• Multi-Radar Integration: Combines long-range and fire-control radars for 360° coverage.

• Electronic Warfare Resilience: Phased array radars and frequency-hopping technologies make it resistant to jamming.

• Networked Defence: Integrates with legacy systems like S-300, Pantsir, and the Indian Integrated Air Command and Control System (IACCS).

• Altitude and Range Flexibility: Engages targets from as low as 30 meters to as high as 30 km.

Combat Debut: Pakistan’s May 2025 Assault

The system’s first real-world test came during Pakistan’s May 7–8, 2025, aerial attack on India. Over 15 drones and missiles targeted cities including Jammu, Srinagar, Amritsar, Bhuj, and 11 others.

Key performance outcomes:

• The Big Bird radar detected the multi-vector assault early, giving command centers critical minutes to respond.

• S-400 launchers intercepted 8–15 aerial threats, including high-speed drones and short-range ballistic missiles.

• In Jammu and other cities, planned blackouts minimized civilian casualties and collateral damage.

• This engagement validated years of procurement, simulation, and strategic deployment across critical border zones.

Deployment Timeline and National Integration

India’s acquisition followed a meticulous rollout:

• 2015: Approval by India’s Ministry of Defence.

• 2016: Inter-governmental framework agreement signed with Russia.

• October 2018: Contract formalized for $5.4 billion.

• December 2021: First S-400 squadron deployed in Punjab, covering Jammu & Kashmir.

• By 2025: Four squadrons operational, fifth expected by 2026.

These units are now strategically positioned across Punjab, Jammu & Kashmir, Gujarat, Rajasthan, and Sikkim, offering a protective arc across both the LoC and LAC.

Peacetime Testing and Validation

Before its combat debut, the S-400 underwent rigorous field trials. In July 2024, a comprehensive Indian Air Force exercise recorded 80% kill success rates in simulated combat scenarios. Integration drills with indigenous systems like Akash and Barak enhanced its adaptability.

Limitations and Lessons Ahead

While highly capable, the S-400 has strategic limitations:

• It is effective only against short- and intermediate-range ballistic missiles (≤3,500 km).

• Each battalion costs ~$200 million, adding pressure on fiscal planning and maintenance cycles.

• Drone swarms, due to their sheer numbers and low radar cross-section, remain a challenge.

Yet, its proven performance in peacetime and combat alike affirms its strategic relevance.

In Summary: A Silent Shield in a Noisy World

As Indian cities temporarily dim their lights to protect themselves, the S-400’s systems glow bright on command screens. It is not just a Russian import or a hardware acquisition; it is a declaration of India’s strategic preparedness. The Sudarshan Chakra’s combat baptism in May 2025 has redefined the air defence doctrine for the subcontinent—restoring the balance of deterrence and giving millions of Indians the confidence to sleep, even in darkness.

And, I share my prophetic tweet.

Pakistan (14.08.1947–08.05.2025)

Rot in hell!

(Save this tweet)

By Karan Bir Singh Sidhu, IAS (retd.) (Punjab Cadre, 1984 batch), policy analyst and geo‑strategic expert, retired Special Chief Secretary, Government of Punjab, and former Deputy Commissioner Amritsar (1992–96), Additional Deputy Commissioner Amritsar (1990–92), District Magistrate, Police District Batala (1989) – a frontline administrator who battled Pakistan‑abetted proxy war.