Aug 22, 2025
15
mins read
The S-400 Triumf is a Russian-developed long-range surface-to-air missile (SAM) system and is widely regarded as one of the world’s most advanced air defence systems. Designed to detect, track, and destroy multiple incoming aerial threats, the S-400 can engage everything from fighter jets and UAVs to cruise and ballistic missiles Its long radar detection range (up to ~600 km) and high-speed missiles (Mach 14) allow interceptions at altitudes up to 30 km. For India, acquiring the S-400 (nicknamed “Sudarshan Chakra”) has significantly strengthened air defence. It adds a crucial layer to India’s multi-tiered shield (alongside indigenous PAD/AAD and medium-range Barak/Akash systems) and enhances deterrence against Pakistan and China.
In August 2025, the Indian Air Force publicly highlighted the S-400’s role in Operation Sindoor during clashes with Pakistan. IAF Chief Marshal A. P. Singh stated that the Russia-supplied S-400 system had been a “game-changer,” helping shoot down at least five Pakistani jets and one large aircraft.
He noted that the S-400’s long kill range kept enemy aircraft at bay.The S-400 deal was also in the news for defying U.S. sanctions under CAATSA.
Despite pressure, India signed a $5.43 billion contract in 2018 for five S-400 regiments, emphasizing strategic autonomy. Its recent performance against drones and missiles has validated India’s decision
Table of content
Advanced Detection and Tracking
Detection range: Up to 600 km with 360° coverage using advanced phased-array and panoramic radars.
Target tracking: Simultaneously tracks 80-300 targets and engages up to 36 at once.
Radar systems: Includes 91N6E Big Bird (long-range detection), 92N6E Grave Stone (mid-range guidance), and 96L6E Cheese Board (low-flying targets)
Stealth detection: Capable of detecting stealth aircraft like F-35 and J-20.
Missile Arsenal and Range
40N6E: 400 km range, 30-35 km altitude (long-range)
48N6DM/48N6E3: 250 km range, 27 km altitude (medium-range)
9M96E2: 120 km range, 30 km altitude (short to medium-range)
9M96E: 40 km range, 20 km altitude (short-range)
Performance Capabilities
Speed: Intercepts targets moving up to Mach 14 (17,000 km/h).
Response time: 9-10 seconds from detection to engagement.
Altitude coverage: Destroys targets from 10 meters to 30 km height.
Guidance systems: Uses active radar homing and semi-active radar homing, inertial, and satellite guidance.
Integrated System Design
Command control: 55K6E module coordinates launchers and radars for rapid response
Battery composition: Includes surveillance radars, command posts, engagement radars, and launch vehicles
Versatile threats: Effectively counters aircraft, ballistic missiles, cruise missiles, and drones
Long-Range Ballistic Missile Defence: The S-400 can intercept incoming ballistic missiles in their terminal phase at high altitude. Its long-range radar and high-speed missiles allow it to hit targets up to 30 km altitude. This adds a crucial layer to India’s BMD shield on top of its PAD/AAD systems.
Stealth and Hypersonic Threats: Its phased-array radars and multi-mode tracking can detect low-observable (stealth) aircraft. The system is also considered capable of countering future hypersonic glide vehicles with its extreme speed and high-altitude engagement envelope.
Rapid Deployment: Designed for mobility, S-400 components are truck-mounted. A battery can be made operational in 5–10 minutes and relocate quickly (“shoot-and-scoot”), making it hard to target.
High-Altitude Surveillance: With advanced X-band and S-band radars, the S-400 provides early warning and precise tracking of fast jets and missiles. Its fire-control radar constantly refines target data for missile guidance.
Layered Defence: Firing up to four missile types, the S-400 creates overlapping layers. For instance, a high-altitude ballistic missile might first be engaged by a 40N6 (400 km range) and, if needed, intercepted by shorter-range 48N6 or 9M96 missiles at closer range. This multi-tier scheme greatly increases kill probability against complex raids.
Image Credit: India Today Group
Radars: Key radars include a 96L6E/96L6E2 3D surveillance radar (wide-area, 600 km range) and one or more X-band engagement radars for missile guidance. The 96L6E can maintain tracking on hundreds of targets in cluttered environments. Advanced phased-array architecture makes them resilient to jamming.
Launchers: Missile launchers (transporter-erector-launchers or TELs) carry 4 canisters each. Each full battery has 8 TELs (32 tubes) and multiple missile types. A squadron (2 batteries) thus supports over 128 ready missiles.
Guidance Modes: The system uses combined guidance – missiles have inertial navigation with mid-course updates (via datalink from radar) and active/passive radar seekers for terminal homing. This multi-mode approach maximizes hit chances against agile targets.
Command & Control: A central vehicle fuses radar data, identifies threats, and tasks launchers. Data links also allow S-400 to share tracking info with other systems (e.g. S-300, Barak-8) for integrated defence. Modern software allows real-time target handover between batteries and with IAF control centers.
Mobility: All components are road-mobile. The system’s “ready to fire” state can be achieved in ~5 minutes. This mobility ensures it can be rapidly deployed along India’s northern and western borders or redeployed as needed.
Support Infrastructure: The S-400 requires robust logistics: trained crews for operation/maintenance, secure fuel and power supplies, and periodic software/radar updates. Each squadron includes support vehicles for repair, power generation and communications.
The S-400 units are networked into India’s larger air defence grid. They complement indigenous and foreign systems (PAD/AAD, Barak-8, Akash, etc.) in a layered architecture.
S-400 squadrons are deployed to cover critical sectors; as of 2025 three squadrons are operational (covering Chinese and Pakistani borders), with two more to arrive by 2026.
The system’s radars and C2 link into IAF’s Air Defence Control Centres, enabling real-time data sharing. This means fighter aircraft and ground systems can see the same tracks and coordinate responses.
During exercises and operations (e.g. Operation Sindoor), S-400 crews and IAF fighters (Su-30, Rafale, etc.) have practiced joint tactics, where S-400 batteries provide protective fire while fighters conduct offensive missions. This synergy allows India’s Air Force to project power while minimizing homeland vulnerability
Regular Maintenance: The S-400’s advanced electronics and hydraulics demand frequent checks. Each radar and launcher undergoes scheduled diagnostics, and missile stocks require climate-controlled storage.
Upgrades: Software and firmware are periodically updated (often by Russia under contract) to add new features or address threats (e.g. new missile types, anti-jamming). The 2018 deal includes technical support from Russia for 8 years.
Crew Training: Operating the S-400 requires specialized training for radar operators, missile technicians, and command officers. India’s IAF and Army personnel have undergone training in Russia as part of the procurement.
Logistics: Deployment involves road convoys of vehicles, generators, and test equipment. The “shoot-and-scoot” capability means after firing, launchers must be moved; this needs coordination with transport units.
Support Infrastructure: Air defence units maintain spare radars, engines, and missile parts. Joint drills ensure that maintenance units can service the system even during prolonged stand-off deployments.
The S-400 missile system surpasses other air defence systems such as the MIM-104 Patriot, HQ-9, THAAD, and S-300PMU with its longer detection range, versatile missile types, and advanced tracking capabilities. This gives it superior adaptability and comprehensive coverage across various defence scenarios, making it a critical component of India’s air defence network.
System | Developer | Radar Detection Range | Missile Capability | Key Strengths | Limitations Compared to S-400 |
S-400 | Russia | Up to 400 km | Multiple missile types; long-range interception | Superior tracking, multi-target engagement, adaptable for diverse threats | - |
MIM-104 Patriot | USA | 150 km | PAC-3 hit-to-kill missiles effective against aircraft, missiles, and drones | Effective missile defence against varied threats | Shorter radar range; fewer missile options |
HQ-9 | China | 200 km | Active radar-homing missiles, cold launch capability | Good tracking and launch capabilities | Shorter range; limited missile variety |
THAAD | USA | 200 km | Optimized for intercepting intermediate-range missiles endo-atmospherically | Strong missile defence against ballistic missiles | Limited detection range; targets missiles only |
S-300PMU | Russia | 200 km | Multiple missile options; tracks up to 300 targets | Multiple simultaneous target tracking | Older system, shorter range than S-400 |
This comparison highlights the strategic advantage of the S-400 in India’s air defence system with emphasis on range, missile diversity, and tracking technology, making it a pivotal part of India’s missile defence framework.
Regional Deterrence: The S-400 extends India’s reach deep into neighboring airspace. With a 400 km missile range, it can theoretically enforce No-Fly Zones over most of Pakistan and large swathes of China’s border areas. This deters hostile incursions and constrains enemy air operations.
City and Asset Defense: The S-400 provides a high-altitude shield over major cities, strategic assets, and critical infrastructure within its 400 km engagement range. For example, a single S-400 regiment deployed near Delhi can secure the entire National Capital Region and surrounding areas. To protect multiple metros like Delhi, Mumbai, or Kolkata, separate deployments are required. This layered coverage boosts homeland security against long-range threats.
Naval Force Protection: Land-based S-400 radars can track naval strike groups (aircraft carriers, missile boats) hundreds of kilometers out to sea. This “sea denial” capability helps protect India’s maritime borders and commerce.
Power Projection: By guarding its own assets, India can focus offensive air operations outward. S-400 deterrence means IAF fighter-bombers can operate with less worry of immediate retaliation, thus strengthening India’s overall power projection.
Geopolitical Leverage: Possessing a system comparable to those of US and Chinese militaries elevates India’s strategic posture. It signals to rivals that India will not be easily vulnerable to air or missile strikes.
Integration and Autonomy: The deal with Russia, despite US pressure, underscored India’s strategic autonomy. It also paved the way for CAATSA waiver talks and diversified India’s supplier base. This impacts India’s foreign relations and defence planning.
The S-400 missile system, known as "Sudarshan Chakra" in India, played a crucial role during Operation Sindoor in May 2025 following the deadly Pahalgam terror attack.
After India conducted targeted strikes on terrorist camps in Pakistan, Pakistan retaliated with coordinated drone and missile attacks aimed at 15 Indian cities, including Jammu, Amritsar, Ludhiana, and Bhuj.
The S-400 air defence system successfully intercepted and neutralized all incoming Pakistani threats, preventing damage to critical military installations and civilian areas.
This marked the first combat deployment of the S-400 in India, demonstrating its ability to track and engage multiple aerial targets simultaneously within a 400 km range.
The system provided robust airspace protection, allowing India's offensive operations to proceed without diverting resources for homeland defense.
The successful interception reinforced the S-400's role as a vital component of India's missile defence system, enhancing national security and regional deterrence capabilities.
The S-400 air defence system is primarily defensive and cannot perform offensive surface strikes or capture enemy territory.
The close military cooperation between China and Pakistan poses a two-front challenge, complicating India’s air defence strategy.
The S-400 currently shows limited ability against emerging threats like hypersonic glide vehicles and has gaps in short-range defence against intense rocket attacks.
High acquisition and maintenance costs of the S-400 constrain India’s defence budget and limit funding for other military modernization.
Purchasing more S-400 units may risk geopolitical consequences, including potential US sanctions and difficulty in integrating with Western defence systems.
While the S-400 significantly enhances India’s missile defence system, these strategic and operational constraints remain important considerations.
Q1: How is the S-400 air defence system technically superior to any other system presently available in the world? (UPSC Mains 2021)
Q.How many S-400 systems does India have?
A.India signed for 5 S-400 regiments in 2018. As of 2025, three regiments (squadrons) are operational (deployed to northern and western borders) and the remaining two are expected by 2026.
Q.Why is the S-400 considered superior?
A.It offers unmatched range (400 km), high speed (Mach 14), and multi-layer defense with 4 missile types. Its phased-array radars can track 100+ targets simultaneously, far exceeding most Western systems. These features make the S-400 arguably the world’s best current long-range SAM system.
Q.How many missiles does an S-400 have?
A.One S-400 regiment consists of two batteries, each battery having ~8 launchers (4 tubes each). In practice, a full battery can support up to ~128 missiles (of various types) ready to fire. This allows a single regiment to engage many targets simultaneously.
Q.Can S-400 shoot down stealth aircraft?
A.While the S-400’s radars are not specifically designed for stealth, its multi-band radars and long detection range improve chances against low-observable targets. It is believed capable of challenging aircraft like the F-22/F-35 in certain aspects. Its layered missile mix also allows engagement of smaller radar returns.
The S-400 Triumf is a cornerstone of India’s modern air defence. Its key features – long radar range, high-speed multi-layered missiles, and networked sensors – allow India to counter advanced threats like ballistic missiles, stealth fighters, and cruise missiles. Operational use during recent conflicts has validated its role as a “game-changer”. Strategically, S-400 boosts deterrence by covering vast enemy airspace and protecting India’s cities and forces. Maintaining this system requires continual upgrades and training, but its benefits – enhanced security and international leverage – are immense. Overall, the S-400 significantly enhances India’s long-range air defence and underpins its regional strategic posture.
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