How is S-400 air defence system technically superior to any other system presently available in the world? (Answer in 150 words)

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S-400 हवाई रक्षा प्रणाली, विश्व में इस समय उपलब्ध अन्य किसी प्रणाली की तुलना में किस प्रकार से तकनीकी रूप से श्रेष्ठ है ? (150 शब्दों में उत्तर दीजिए)

The question as printed in the 2021 General Studies paper

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Model answer

Drafted with AI by UPSC Answer Check against this question's marking rubric, to the 150-word length. UPSC does not publish answers for Mains — this is one way to score well, not an official key. How we build rubrics and answers.

(a) Layered missiles: The Russian S-400 Triumf is among the most capable long-range air defence systems because one battery integrates four missile types: 40N6E (400 km), 48N6E3 (250 km), 9M96E2 (120 km) and 9M96E (40 km), covering the 40-400 km spectrum against aircraft, cruise missiles and some ballistic targets.

(b) Sensors and saturation handling: Its 91N6E panoramic radar (about 600 km detection), 96L6E acquisition radar and 92N6E fire-control radar are claimed to detect low-observable targets. It can track about 300 targets and engage 36 with 72 missiles simultaneously, with active-radar homing on the short-range missiles.

(c) Mobility and networking: Road-mobile launchers and a networked command post allow deployment in about five minutes, giving quick reaction and survivability.

These parameters give it an edge in range and saturation handling over systems like the US Patriot PAC-3 and Chinese HQ-9, though the claims are manufacturer figures; for ballistic missile defence, the US THAAD is the specialised comparison. For India, it deters along the China and Pakistan borders despite CAATSA concerns, and the IAF chief credited it in Operation Sindoor (May 2025) with long-range kills.

How this answer will be evaluated

Framework: Security: classify threat, vulnerability, response; stay calm

What earns full marks: Precise technical comparison with specific capabilities (range, radar, missiles)

Evaluation rubric

Each sub-part is marked on its own, against the marks and word limit printed on the paper.

The answer Technical features distinguishing S-400 from other air defence systems 10 marks · 150 words

explain— definition/context → points in order → small example → short close
Must cover
- Multi-layered engagement (short, medium, long range)
- Simultaneous tracking and engagement of multiple targets
- Active radar guidance (fire-and-forget capability)
- Counter-stealth and anti-cruise missile capability
Loses marks
- Vague generalities without technical specifics
- Focusing on geopolitical context over technical specs
- Listing features without explaining superiority
Earns more
- Mention of specific radar range (e.g., 600km)
- Comparison with S-300 or Patriot systems
- Reference to 48N6E2 missile capability
Extra mark
- Specific engagement range figures (e.g., 400km)
- Mention of specific missile types (40N6, 9M96)

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