Air Defence Systems
Science & Technology › Defence Technology and Missile Systems · Topic 16.18
Air defence is the set of weapons, sensors and command systems that protect a country or a force from attack by aircraft, missiles, rockets and drones. It is built in layers: radars and early warning aircraft detect threats, a command and control network links them, and weapons of different ranges, from guns and shoulder fired missiles to long range missiles, engage the target. India's layers include very short range systems such as the Igla-S, short range systems such as the Akash and the Quick Reaction Surface to Air Missile, medium range systems such as the MRSAM, and long range systems such as the Russian S-400 Triumf, ordered in October 2018 for about 5.4 billion dollars. In August 2025 the Prime Minister announced the Sudarshan Chakra Mission for a national shield.
5 min read · UPSC Prelims · Science & Technology · Defence Technology and Missile Systems
At a Glance
- Long range S-400 Triumf
- Medium range MRSAM, Akash-NG
- Short range Akash, QRSAM
- Very short range Igla-S, VSHORADS
- New mission Sudarshan Chakra, 2025
- Exam link UPSC Prelims, Science & Technology: Defence Technology and Missile Systems
Where Does It Fit?
This topic follows the account of 3D printing and autonomous weapons. It brings together the radars, missiles and networks that protect against air threats, and links with earlier topics on anti-ballistic missiles, drones and directed energy weapons. Previous topic: 3D-Printed Munitions and Lethal Autonomous Weapons. Next topic: Missile Classification by Type, Launch Platform, Range and Propulsion System.
How Is Air Defence Organised in Layers?
| Layer | Systems and features |
|---|---|
| Very short range | Man portable missiles (MANPADS) such as the Russian Igla-S, and DRDO’s VSHORADS, with a range of a few km, used against low flying aircraft, helicopters and drones. Guns such as the L70 and Schilka also serve here |
| Short range | Akash (25 to 30 km), QRSAM (about 30 km, designed to move with armoured columns), Spyder and Pantsir types |
| Medium range | MRSAM or Barak-8 made with Israel (up to 70 km or more), Akash-NG, and the NASAMS-II ordered from the United States for the national capital |
| Long range | S-400 Triumf from Russia (up to 400 km). India signed for five squadrons in October 2018, with deliveries from December 2021, and remaining ones due by around 2026 to 2027 |
| Project Kusha | DRDO’s long range surface to air missile project for a 150, 250 and 350 km family |
| Anti-ballistic | Phase-I and II missile defence, as in Anti-Ballistic Missile System |
| Detection | ground radars, AWACS such as Netra and Phalcon, and satellites |
How Are the Layers Linked and What Is New?
- Integrated Air Command and Control System: IACCS, the Air Force network that links radars and weapons to give a common picture, operational since 2010
- Akashteer: an automated air defence control and reporting system of the Army, built by Bharat Electronics Limited and introduced from 2022 to 2023
- Navy: shipborne systems such as Barak-1, Barak-8 and MRSAM protect fleets, together with close-in weapon systems
- Counter-drone: radars, jammers, guns and lasers for small drones, with cost as a central problem
- Operation Sindoor: in May 2025 India said its layered air defence including the S-400, Akash and others defeated Pakistani drone and missile attempts, and the details should be taken from official statements
- Sudarshan Chakra Mission: announced on 15 August 2025, a plan to build a national security shield by 2035 using indigenous technology, with strike and defence capabilities, which will use a network of sensors and interceptors
- Indigenous efforts: DRDO and private industry work on Akash-NG, QRSAM, VSHORADS, Project Kusha and laser systems
- Imports: India continues to import Russian, Israeli and United States air defence
What Else Should You Remember?
- Air Defence Ground Environment: the earlier network of radars
- Ground based air defence: Army Air Defence Corps is the arm of the Army
- Combined arms: air defence units move with armoured and infantry units
- Radars: Rajendra radar of Akash, Swathi weapon locating radar and Ashwini low level radar
- Electronic warfare: jamming to confuse enemy missiles
- Passive defence: shelters, camouflage and decoys
- Iron Dome: Israel’s system against short range rockets, with Tamir interceptors
- Patriot: a United States system used in many countries
- Cost exchange: shooting cheap drones with costly missiles is not sustainable
- Saturation attack: sending many cheap threats to overwhelm defences
- Hypersonic challenge: fast manoeuvring weapons are hard to defend against, as in Hypersonic Glide Vehicles and Hypersonic Cruise Missiles
- Stealth challenge: low observable aircraft are harder to detect, as in Stealth Technology
- CAATSA: a United States law of 2017 on sanctions for buying Russian arms, which created debate about the S-400 deal
- Pakistan’s systems: China-origin HQ-9 and others
- Defence of ships: close-in weapon systems and decoys
- Link: AWACS are in Airborne Warning and Control System (AWACS)
- Link to laser defence: see Directed Energy Weapons
Why Does It Matter for the Exam?
- Layers: very short to long range
- Systems: S-400, Akash, MRSAM, QRSAM
- Networks: IACCS, Akashteer
- Current affairs link: Sudarshan Chakra Mission and Kusha
- Common errors: saying MRSAM is made with Russia or Akash is imported
As an analytical point, layered air defence with strong sensors and networks is more effective than any single system. The rise of cheap drones and hypersonic weapons needs low-cost interceptors and new technologies.
Why Is This Topic Important?
- Layers Ranges
- Networks IACCS
- New Mission
What Came Next?
The next topic covers missile classification by type, launch platform, range and propulsion. Next topic: Missile Classification by Type, Launch Platform, Range and Propulsion System.
Key People and Terms
- SAM Surface to air missile
- MANPADS Man portable air defence system
- IACCS Integrated Air Command and Control System
- QRSAM Quick Reaction SAM
- MRSAM Medium Range SAM
- CIWS Close-in weapon system
Exam Corner
Points to Remember
- S-400 contract: October 2018, about 5.4 billion dollars.
- MRSAM is with Israel; S-400 with Russia.
- IACCS operational 2010.
- Sudarshan Chakra Mission: 15 August 2025.
- Akash range about 25 to 30 km.
Do Not Confuse With
- Akash and S-400 Indigenous short-medium versus Russian long range
- MANPADS and SAM site Shoulder fired versus fixed or mobile launcher
- IACCS and Akashteer Air Force network versus Army system
Memory Hook
Igla at the shoulder, Akash in the middle, S-400 at the top; IACCS ties them all.
Mains Angle
Questions ask for systems, ranges and countries. These points help.
- Layers Range bands
- Networks Command
- Threats Drones, hypersonic
A Question You May Face
An original practice question, not a past paper question.
“Explain the concept of layered air defence and discuss India’s capabilities and the challenges posed by new aerial threats.”
How to Answer
- Concept Layers.
- Systems Indian and imported.
- Networks IACCS.
- Threats Drones, hypersonics.
GS Relevance
Frequently Asked Questions
What is layered air defence?
Layered air defence combines weapons of different ranges and sensors so that a threat that passes one layer can be engaged by the next. India uses man portable missiles and guns for very short range, Akash and QRSAM for short range, MRSAM for medium range, and S-400 for long range, all linked by networks.
What is the S-400 Triumf?
The S-400 Triumf is a Russian long range surface to air missile system able to engage aircraft, drones and some ballistic missiles at up to 400 km. India signed a contract in October 2018 for five squadrons at about 5.4 billion dollars, and the deliveries began in December 2021.
What is MRSAM?
The Medium Range Surface to Air Missile, also called Barak-8, is a system jointly developed by DRDO and Israel Aerospace Industries. It is used by the Army, Air Force and Navy with a range of about 70 km and above, to defend against aircraft, missiles and drones.
What is the IACCS?
The Integrated Air Command and Control System is a computer network of the Indian Air Force that links radars, aircraft and missile units and gives a single real time picture of the air situation. It became operational in 2010 and lets commanders assign targets to the best weapon.
What is the Sudarshan Chakra Mission?
The Sudarshan Chakra Mission was announced by the Prime Minister on 15 August 2025 as a plan to build a national shield against air and missile attacks by 2035, with indigenous sensors and weapons that can also strike back. The scope and design are still being defined.
PYQ Practice — Statement Analysis
1 The S-400 is a Russian long range air defence system.
Ordered in 2018.
2 MRSAM was developed jointly with Israel.
Also called Barak-8.
3 Akashteer is an air defence control system of the Army.
Built by BEL.
4 Igla-S is a long range missile.
It is a very short range MANPADS.
Past Mains Questions on This Topic
This topic comes under Defence Technology and Missile Systems. UPSC Mains questions asked on the matching syllabus topic, year-wise with marks:
Related Topics
Browse the full Science & Technology index