Defense Technology & Combat Systems
Missile Technology & Key Concepts
Missile Technology & Key Concepts
| How does the flight path differ between Cruise and Ballistic missiles? | - Ballistic Missiles: Leaves the atmosphere and follows a high parabolic gravity-controlled trajectory to strike. Cruise Missiles: Remains within the atmosphere, flying at low altitudes and following flat, terrain-hugging paths. |
| Compare the propulsion phases of Cruise vs Ballistic missiles. | - Ballistic: Rocket-powered only during the initial launch phase (boost phase). Cruise: Jet-propelled continuously throughout its flight. |
| What is the UPSC Trap regarding propulsion type of cruise vs ballistic? | - UPSC Trap Ballistic missiles are rocket-powered only initially; cruise missiles are jet-propelled continuously. |
| What is the Mach boundary for subsonic flight, and which Indian cruise missile is subsonic? | - Subsonic: < Mach 0.8 (e.g., Nirbhay cruise missile). |
| What are the speed boundaries for transonic and supersonic flight? Give an Indian supersonic example. | - Transonic: Mach 0.8 – 1.2. Supersonic: Mach 1.2 – 5.0 (e.g., BrahMos — Mach 2.8–3.0). |
| What constitutes hypersonic speed? Give Indian examples and the UPSC speed trap. | - Hypersonic: > Mach 5.0 (e.g., Shaurya tactical, HSTDV vehicle). UPSC Trap Hypersonic is strictly ≥ Mach 5.0 (not Mach 3.0). |
| Define tactical missiles with Indian examples and ranges. | Tactical Missiles: Designed for battlefield use. - Prahaar: 150 km range. - Pralay: 150 – 500 km range. |
| What is the range of Short-Range Ballistic Missiles (SRBM)? Give an example. | - SRBM (Short Range): < 1,000 km range (e.g., Prithvi series). |
| What is the range of Medium-Range Ballistic Missiles (MRBM)? Give examples. | - MRBM (Medium Range): 1,000 – 3,000 km range (e.g., Agni-I, Agni-II, Agni-P). |
| What is the range of Intermediate-Range Ballistic Missiles (IRBM)? Give examples. | - IRBM (Intermediate Range): 3,000 – 5,500 km range (e.g., Agni-III, Agni-IV). |
| What is the range of Intercontinental Ballistic Missiles (ICBM)? Give examples. | - ICBM (Intercontinental): > 5,500 km range (e.g., Agni-V, Agni-VI). |
| What is the primary difference in propellants used between the Prithvi and Agni families? | - Prithvi Family: 100% Liquid-fueled. Agni Family: 100% Solid-fueled. UPSC Trap All Agni variants are strictly solid-fueled. |
| Detail the stage count and range of Prithvi-II. | - Prithvi-II: First indigenous surface-to-surface missile (SSM) mainstay; has a 350 km range and is liquid-fueled. |
| Detail the stages and ranges of Agni-I, Agni-II, and Agni-III. | - Agni-I: 700–900 km range | 1-stage solid propellant. Agni-II: 2,000+ km range | 2-stage solid propellant. Agni-III: 3,000+ km range | 2-stage solid propellant. |
| Explain the unique design features and range of Agni-IV. | - Agni-IV: 4,000 km range | 2-stage | Features a composite motor body and high accuracy guidance systems. |
| Detail the stages, launch style, and special capability of Agni-V. | - Agni-V: 5,500+ km range | 3-stage | Canisterized (road-mobile launch) & MIRV-capable. Successfully tested under "Mission Divyastra" in March 2024. |
| What are the projected range and characteristics of the under-development Agni-VI? | - Agni-VI (Expected): Solid-fueled ICBM with a range of 8,000–12,000 km and multi-warhead (MIRV) capability. |
| What is Dhanush? Detail its range, fuel type, and the associated UPSC Trap. | - Dhanush: 350 km range. It is a liquid-fueled naval variant of Prithvi-II (ship-launched). UPSC Trap Dhanush is a Prithvi variant (Liquid fuel), NOT Agni (Solid fuel). |
| Explain Agni-P (Prime): stages, range, and target utility of its MaRV capability. | - Agni-P (Prime): 1,000–2,000 km range | 2-stage | Canisterized | Equipped with MaRV (Maneuverable Reentry Vehicle) designed for terminal precision strikes against maneuvering warships. |
| How does the MIRV 'bus' release mechanism operate in space? | - A single missile carries multiple warheads on a maneuverable "bus" stage in space. The bus releases warheads at separate vectors/times to hit different targets hundreds of kilometers apart. |
| What is the UPSC Trap regarding MIRV target locations? | - UPSC Trap MIRV does NOT mean hitting the same target with multiple bombs; it guides warheads to separate targets independently. |
| Which Indian missile platform first demonstrated MIRV capability? | - Agni-V: Demonstrated under the flight test named Mission Divyastra in March 2024. |
| Distinguish between 'cold launch' and 'hot launch' in canister systems. | - Cold Launch: A gas generator ejects the missile from its canister first; the rocket motor ignites outside in mid-air (safer for the launch vehicle). Hot Launch: Rocket motor ignites inside the canister/silo, requiring thermal protection. |
| What are the key operational advantages of canisterized launching systems? | - Provides instant launch-on-demand (since solid fuel is pre-loaded), environmental isolation (hermetically sealed), and high road/rail mobility. |
| Describe the two-stage propulsion system of the BrahMos cruise missile. | - Propulsion stages:
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| What is the UPSC Trap regarding Ramjet engines? | - UPSC Trap Ramjets only work at supersonic speeds; a rocket booster is required to launch and accelerate the vehicle first. |
| How did India joining the MTCR in 2016 impact the BrahMos program? | - India's entry into the Missile Technology Control Regime (MTCR) allowed extension of the BrahMos range from the export-controlled limit of 290 km to 500+ km. |
| What is BrahMos-NG? | - A lighter, next-generation variant of BrahMos designed for integration with the Tejas LCA. |
| What is the role and guidance system of the Astra missile? | - Astra: Indigenous Beyond Visual Range Air-to-Air Missile (BVRAAM) with 110+ km range, using active radar terminal guidance. |
| What is RudraM-II, and what is its role in SEAD operations? | - RudraM-II (Tested June 2026): Indigenous, solid-fueled, supersonic air-to-surface anti-radiation missile. Used in SEAD (Suppression of Enemy Air Defenses) to home in on enemy RF/radar emitters. UPSC Trap Rudram targets radio frequency radars, not nuclear radioactivity. |
| What is SMART, and how does it assist in ASW? | - SMART (Supersonic Missile Assisted Release of Torpedo): Standoff rocket-assisted torpedo drop for Anti-Submarine Warfare (ASW). |
| What is the Rampage weapon system, and where is it imported from? | - Rampage: Supersonic air-to-ground precision standoff missile imported from Israel. |
Naval Systems & Ship Projects
Naval Systems & Ship Projects
| How does an SSK submarine differ from an SSN in propulsion and range? | - SSK (Diesel-electric attack): Powered by batteries and diesel engines. Needs oxygen via snorkeling (surfacing slightly) to run engines and recharge batteries, limiting submerged endurance. SSN (Nuclear attack): Powered by an onboard nuclear reactor. Unlimited range/speed, hunter-killer, limited only by crew food supplies. |
| What is the primary role of an SSBN, and how does it support India's nuclear triad? | - SSBN (Nuclear ballistic missile submarine): Carries Submarine-Launched Ballistic Missiles (SLBMs) like K-15 or K-4 to provide a secure, survivable second-strike nuclear deterrent capability. |
| What chemical reaction powers Air Independent Propulsion (AIP) fuel cells? | - Mechanism: Fuel cells combine hydrogen and oxygen chemically to generate electricity directly, releasing only water as a byproduct. |
| How does AIP affect a conventional submarine's submerged endurance and noise profile? | - Allows conventional SSKs to charge batteries without surfacing/snorkeling for atmospheric oxygen. Extends submerged endurance from days to weeks. It is extremely silent because it lacks the reactor cooling pumps of nuclear submarines. |
| What are the two key UPSC traps regarding AIP and submarine noise? | - UPSC Trap AIP does NOT make a sub nuclear; it is an auxiliary fuel-cell generator. AIP fuel-cell submarines are actually quieter than nuclear submarines. |
| Name the six Scorpene-class submarines built under Project 75, their design origin, and builder. | - Kalvari (Scorpene) Class: 6 conventional attack submarines (SSKs):
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| What is the Arihant-class project name, where is it built, and which SLBMs does it carry? | - Arihant Class (SSBN): Developed indigenously under the Advanced Technology Vessel (ATV) project. Built at Ship Building Centre (SBC) Vizag. Carries solid-fueled SLBMs: K-15 (700 km range) and K-4 (3,500 km range). |
| What is INS Aridaman? | - INS Aridaman (2026 context): India's third Arihant-class SSBN. |
| What is Project 75 Alpha? | - A planned program to construct 6 indigenous nuclear-powered attack submarines (SSNs). |
| Detail the origin and configuration of INS Vikramaditya. | - INS Vikramaditya: Russian-origin carrier (ex-Admiral Gorshkov) configured with a STOBAR system. |
| Name India's first indigenous aircraft carrier, its builder, and its launch configuration. | - INS Vikrant (IAC-1): India's first indigenous aircraft carrier. Built by Cochin Shipyard. Uses a STOBAR configuration. |
| What is INS Vishal, and what technology is planned for it? | - INS Vishal (IAC-2): Planned future indigenous carrier designed to utilize EMALS (Electromagnetic Aircraft Launch System). |
| How does STOBAR launch technology work, and how does it impact aircraft payloads? | - STOBAR: Short Take-Off But Arrested Recovery. Uses a ski-jump ramp for takeoff and arrestor wires for landing. The lack of active catapult propulsion limits the maximum fuel and weapon payload aircraft can carry on takeoff. |
| What is CATOBAR, and how does it compare to STOBAR? | - CATOBAR: Catapult Assisted Take-Off But Arrested Recovery. Uses catapults to launch aircraft, allowing heavier aircraft to take off with full payloads. |
| How does EMALS launch aircraft, and what are its advantages? | - EMALS: Electromagnetic Aircraft Launch System. Uses a linear induction motor instead of steam. It is more reliable, has a higher launch rate, and can be calibrated to launch varying weights (from heavy jets to light UAVs). |
| What is the UPSC Trap regarding active Indian carrier launch technology? | - UPSC Trap Current active Indian carriers (Vikrant, Vikramaditya) are STOBAR only. EMALS is future tech planned for IAC-2. |
| Detail Project 15B: ship type, names of all four ships, and builder. | - Project 15B (Visakhapatnam Class): Stealth guided-missile destroyers. Includes:
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| What is Project 17A Nilgiri class: ship type, ship count, and its two key design features? | Project 17A (Nilgiri Class): Stealth frigates (7 ships total). Key features: - Integrated Mast: Houses radar arrays inside a single composite structure to reduce radar cross-section. - Modular Construction: Assembled in pre-fabricated blocks. Built by MDL & GRSE. |
| Detail Project 28 Kamorta class: ship type, ship names, builder, and its unique material feature. | - Project 28 (Kamorta Class): Anti-Submarine Warfare (ASW) corvettes (INS Kamorta, Kadmatt, Kiltan, Kavaratti). Features a carbon-fiber composite superstructure to reduce top-weight, lower the center of gravity, and reduce radar cross-section. Built by GRSE. |
| What is Project Sea Bird? | - A major naval infrastructure project to expand the Karwar Naval Base (Karnataka) into one of India's largest and most strategically protected bases. |
| What is Varunastra, and how does it target submarines? | - Varunastra: Indigenous heavyweight anti-submarine electric torpedo equipped with active-passive acoustic homing. |
| State the size hierarchy of Indian surface warships and the key P28 material UPSC Trap. | - Hierarchy: Destroyers (P15B) > Frigates (P17A) > Corvettes (P28). UPSC Trap P28 uses a carbon-fiber superstructure for weight reduction and radar stealth (not steel). |
Advanced Defense Tech (Space, DEWs & E-Warfare)
Advanced Defense Tech - Space, DEWs & E-Warfare
| What is the fundamental physical concept behind Directed Energy Weapons (DEWs)? | - Uses focused electromagnetic or particle energy (such as lasers, microwaves, or particle beams) to disable or destroy targets instantly without conventional ammunition. |
| What is Durga-2? | - Durga-2: An indigenous laser-based weapon system currently in development by India. |
| What is KALI, and how does it disable targets? | - KALI (Kilo Ampere Linear Injector): An electron/microwave injector. It generates Relativistic Electron Beams (REB) that produce high-power microwave pulses to fry/disable the electronic circuitry of missiles or aircraft. |
| What is the key UPSC Trap regarding KALI's physical mechanism? | - UPSC Trap KALI is NOT a laser; it is a microwave pulse system that destroys circuitry. Durga-2 is the laser. |
| Detail the ADITI scheme: duration, parent initiative, and focus areas. | - ADITI Scheme (2024-2026): Launched under the iDEX (Innovations for Defence Excellence) initiative. It funds startup development of deep-tech military systems, specifically focusing on AI, quantum communications, and DEWs. |
| Name the military communication satellite dedicated to the Indian Navy and its coverage region. | - GSAT-7 (Rukmini): Multi-band communication satellite dedicated to the Indian Navy, providing secure real-time connectivity over the Indian Ocean Region. |
| Which GSAT satellite serves the IAF, and what assets does it link? | - GSAT-7A: Dedicated communication satellite for the Indian Air Force. It links ground radar stations, air bases, and Airborne Early Warning and Control (AEW&C) aircraft. |
| What is GSAT-7B? | - A dedicated communication satellite approved for development to support the Indian Army's tactical communication needs. |
| What is the UPSC Trap regarding the function of the GSAT-7 series? | - UPSC Trap GSAT-7 satellites are strictly communication platforms, NOT surveillance/reconnaissance satellites. |
| Explain how a Fractional Orbital Bombardment System (FOBS) works. | - FOBS: Launches a warhead into a Low Earth Orbit (LEO) rather than a high ballistic arc. Before completing a full orbit, retro-rockets are fired to de-orbit the warhead, causing it to strike its target. |
| Why is a FOBS trajectory harder to detect and intercept than a standard ballistic path? | - It uses a non-parabolic, low-altitude orbit which stays below the radar horizon of traditional early warning networks. It can also approach from unexpected directions (e.g., the South Pole), bypassing radars oriented for North Pole missile paths. |
| What is HAPS/SAP, its operating altitude, and its primary military utility? | - HAPS (High Altitude Platform Station): Solar-powered unmanned aircraft operating in the stratosphere at 17–22 km. It provides persistent, satellite-like local surveillance and communication coverage for months at a fraction of satellite costs. |
Strategic Partnerships & Agreements
Strategic Partnerships & Foundational Agreements
| What is GSOMIA, its year of signing, and its core utility? | - GSOMIA (General Security of Military Information Agreement) - 2002: Establishes protocols for sharing and protecting classified military intelligence between India and the US. |
| What is LEMOA, its year of signing, and its core utility? | - LEMOA (Logistics Exchange Memorandum of Agreement) - 2016: Provides reciprocal logistical access to bases, ports, and airfields for refueling, repairs, and replenishment. |
| What is the UPSC Trap regarding LEMOA's base access? | - UPSC Trap LEMOA provides logistical port access only; it is NOT a permanent troop basing treaty or mutual defense pact. |
| Explain COMCASA, its year of signing, and what it enables. | - COMCASA (Communications Compatibility and Security Agreement) - 2018: Allows the transfer of secure, encrypted communication equipment and real-time data feeds, enabling interoperability during joint operations. |
| What is BECA, its year of signing, and what data does it share? | - BECA (Basic Exchange and Cooperation Agreement) - 2020: Enables the bilateral sharing of unclassified and classified geospatial intelligence, satellite maps, and topographic data for targeting accuracy. |
| Explain the chronological order and mnemonic 'G-L-C-B' for the US agreements. | - Chronology: GSOMIA (2002) → LEMOA (2016) → COMCASA (2018) → BECA (2020). Mnemonic: "G-L-C-B" ("Green Light Can Boost"). |
| What are the threshold limits of the MTCR, and how did India's entry impact its military acquisitions? | - MTCR (Missile Technology Control Regime): Limits proliferation of missiles and UAVs carrying a payload > 500 kg over a range > 300 km. India's 2016 entry allowed it to extend the BrahMos range and acquire MQ-9B armed drones from the US. |
| What is the scope of the Wassenaar Arrangement? | - Export control regime regulating the transfer of conventional arms and dual-use goods and technologies (civilian tech that can be weaponized). |
| What is the focus of the Australia Group? | - An informal forum focusing on export controls to prevent the proliferation of chemical and biological weapons precursors and equipment. |
| What is iCET? | - iCET (US-India Initiative on Critical and Emerging Technology): A bilateral platform to expand cooperation in critical areas like AI, space, quantum computing, and semiconductor supply chains. |
| In which major export control regime is India NOT a member? What is the UPSC Trap? | - India is a member of MTCR, Wassenaar, and Australia Group, but is NOT in the NSG (Nuclear Suppliers Group). UPSC Trap India's entry into the NSG is blocked by China (citing non-NPT signatory status). |
| Identify the partner countries and service branch for Exercise Malabar. What is the UPSC Trap? | - Exercise Malabar: Naval exercise. Conducted between Quad partners: India, USA, Japan, and Australia. UPSC Trap Malabar is a Quad multilateral exercise, not a bilateral one. |
| Describe Exercise Indra: partner, format, and UPSC Trap. | - Exercise Indra: Conducted with Russia. It is a Tri-Services joint exercise (involves Army, Navy, and Air Force forces). UPSC Trap Indra is a tri-service exercise, not a single-service exercise. |
| Pair the following exercises with their partners and service: Yudh Abhyas, Hand-in-Hand, Varuna, Simbex, Nomadic Elephant, and Milan. | - Yudh Abhyas: USA (Army) - Hand-in-Hand: China (Army) - Varuna: France (Naval) - Simbex: Singapore (Naval) - Nomadic Elephant: Mongolia (Army) - Milan: Multi-national (Naval) |
Quick Reference Matrices
Missile Technology Comparison Table
| Missile / System | Class | Speed | Propulsion | Range | Key Feature |
|---|---|---|---|---|---|
| Prithvi-II | SRBM | Short range | Liquid fuel | 350 km | Mainstay of strategic land forces |
| Agni-V | ICBM | Intercontinental | Solid (3-stage) | 5,500+ km | MIRV-capable, canister-launched |
| Agni-P | MRBM | Medium range | Solid (2-stage) | 1,000–2,000 km | Canisterized with MaRV |
| BrahMos | Cruise | Supersonic (Mach 2.8) | Solid + Ramjet | 290–500+ km | Fire-and-forget; Indo-Russian JV |
| Shaurya | Ballistic-Cruise | Hypersonic (Mach 7+) | Solid (2-stage) | 700–1,900 km | Canister-launched tactical missile |
| Astra | Air-to-Air (BVR) | Supersonic | Solid rocket | 110+ km | India's primary BVR air combat missile |
| Rudram | Anti-Radiation | Supersonic | Solid rocket | 100–150 km | SEAD — suppresses enemy radars |
Naval Ship Projects Comparison Table
| Project | Class Type | Core Function | Active Ships | Key Tech | Builder |
|---|---|---|---|---|---|
| Project 15B | Destroyers | Guided-missile defense | Visakhapatnam, Mormugao, Imphal, Surat | Advanced stealth | MDL |
| Project 15A | Destroyers | Fleet air defense | Kolkata, Kochi, Chennai | Predecessor stealth | MDL |
| Project 17A | Frigates | Stealth multi-role | Nilgiri, Vindhyagiri, Mahendragiri | Integrated Mast, modular | MDL & GRSE |
| Project 28 | Corvettes | Anti-Submarine | Kamorta, Kadmatt, Kiltan, Kavaratti | Carbon-fiber, NBC | GRSE |
| Project 75 | Submarines (SSK) | Conventional attack | Kalvari, Khanderi, Karanj, Vela, Vagir, Vagsheer | Scorpene design; AIP retrofit | MDL |
IAF Fleet Inventory
| Platform Name | Type / Class | Indigenisation | Manufacturer / Origin |
|---|---|---|---|
| HAL Tejas (LCA) | Light Combat Aircraft | Pure Indigenous | ADA / HAL |
| HAL Prachand (LCH) | Light Combat Helicopter | Pure Indigenous | HAL |
| HAL Dhruv & Rudra | Advanced Light Helicopters | Pure Indigenous | HAL |
| Akash SAM | Surface-to-Air Missile | Pure Indigenous | DRDO / BDL & BEL |
| Astra Missile | Beyond Visual Range AAM | Pure Indigenous | DRDO / BDL |
| Rudram | Anti-Radiation Missile | Pure Indigenous | DRDO |
| DRDO Netra AEW&C | Airborne Radar | Hybrid / Co-developed | DRDO Radar on Embraer ERJ-145 (Brazil) |
| Su-30 MKI | Air Superiority Fighter | Licensed / ToT | Sukhoi (Russia) / HAL Nasik |
| Dassault Rafale | Multirole Fighter | Foreign Import | Dassault Aviation (France) |
| MiG-29 / MiG-21 | Fighter / Interceptor | Foreign Import | Russia |
| C-17 Globemaster III | Heavy Strategic Airlifter | Foreign Import | Boeing (USA) |
| C-130J Super Hercules | Tactical Airlifter | Foreign Import | Lockheed Martin (USA) |
| CH-47F Chinook | Heavy Lift Helicopter | Foreign Import | Boeing (USA) |
| AH-64E Apache | Attack Helicopter | Foreign Import / JV | Boeing (USA) / Tata TASL JV |
| S-400 Triumf | Long-Range Air Defense | Foreign Import | Russia |
| Spyder SAM | Quick-Reaction SAM | Foreign Import | Israel |
| Phalcon AWACS | Airborne Radar | Foreign Import | Israel on Il-76 (Russia) |
Navy Fleet Inventory
| Platform Name | Type / Class | Indigenisation | Manufacturer / Origin |
|---|---|---|---|
| INS Vikrant | Aircraft Carrier (STOBAR) | Pure Indigenous | Navy WDB / CSL |
| INS Arihant & Arighat | SSBN (Nuclear Ballistic Sub) | Pure Indigenous | ATV Project / SBC Vizag |
| Visakhapatnam-class | P15B Destroyers | Pure Indigenous | MDL |
| Kolkata-class | P15A Destroyers | Pure Indigenous | MDL |
| Nilgiri-class | P17A Stealth Frigates | Pure Indigenous | WDB / MDL & GRSE |
| Kamorta-class | P28 ASW Corvettes | Pure Indigenous | GRSE |
| Varunastra | Heavyweight ASW Torpedo | Pure Indigenous | DRDO (NSTL) / BDL |
| BrahMos | Supersonic Cruise Missile | Co-developed / JV | BrahMos Aerospace (Indo-Russian) |
| Kalvari-class | Conventional SSK Sub | Licensed / ToT | Naval Group (France) / MDL |
| INS Vikramaditya | Aircraft Carrier (STOBAR) | Foreign Import | Russia |
| Talwar-class | Guided-missile Frigate | Foreign Import | Russia |
| P-8I Neptune | Maritime Patrol Aircraft | Foreign Import | Boeing (USA) |
| MH-60R Seahawk | Naval Helicopter | Foreign Import | Lockheed Martin (USA) |
| INS Chakra | SSN (Nuclear Attack Sub) | Leased | Russia (returned) |
Army Fleet Inventory
| Platform Name | Type / Class | Indigenisation | Manufacturer / Origin |
|---|---|---|---|
| Arjun (Mk-1 / Mk-1A) | Main Battle Tank | Pure Indigenous | CVRDE (DRDO) / HVF Avadi |
| Dhanush Howitzer | 155mm Towed Artillery | Pure Indigenous | AWEIL (Bofors-based) |
| ATAGS | Advanced Towed Artillery | Pure Indigenous | DRDO / Tata & Bharat Forge |
| Pinaka MBRL | Multi-Barrel Rocket Launcher | Pure Indigenous | DRDO / L&T & Tata |
| Nag / Helina | Anti-Tank Guided Missile | Pure Indigenous | DRDO / BDL |
| T-90S Bhishma | Main Battle Tank | Licensed / ToT | Russia / HVF Avadi |
| T-72 Ajeya | Main Battle Tank (Legacy) | Licensed / ToT | Soviet Union / HVF Avadi |
| K9 Vajra-T | Self-propelled Howitzer | Licensed / ToT | Hanwha (South Korea) / L&T |
| M777 Howitzer | Ultra-light Towed Howitzer | Foreign Import | BAE Systems (USA) |
| SIG 716 | Battle Rifle | Foreign Import | SIG Sauer (USA) |
| Carl Gustaf M4 | Recoilless Rifle | Foreign Import | Saab (Sweden) |
Mnemonics for Exam Recall
All Mnemonics in One Place
Mnemonic 1: Foundational Agreements — "G-L-C-B" (Green Light Can Boost)
| Letter | Agreement | Year | Core Utility |
|---|---|---|---|
| G | GSOMIA | 2002 | Classified intelligence sharing |
| L | LEMOA | 2016 | Logistics & base access |
| C | COMCASA | 2018 | Secure communication hardware |
| B | BECA | 2020 | Geospatial & satellite mapping |
Mnemonic 2: IGMDP Arsenal — "P-A-T-N-A"
- Prithvi → Surface-to-surface SRBM (Liquid fuel)
- Agni → Surface-to-surface MRBM to ICBM (Solid fuel)
- Trishul → Short-range SAM (Decommissioned, replaced by Akash)
- Nag → Fire-and-forget ATGM (Anti-Tank)
- Akash → Medium-range SAM
Mnemonic 3: Carrier Launch Tech — "S-C-E" (Scale of Tech)
- STOBAR → Ski-jump (Vikrant, Vikramaditya)
- CATOBAR → Catapult (planned)
- EMALS → Electromagnetic (INS Vishal)
Mnemonic 4: BMD Layers — "EXO-ENDO" (Out then In)
- EXO-atmospheric (PAD/PDV) → Outside atmosphere (>50 km)
- ENDO-atmospheric (AAD/Ashwin) → Inside atmosphere (<30 km)
Mnemonic 5: Sub Classifications — "SKiN" (SSK → SSN)
- SSK → Diesel-electric (Konventional) attack sub
- SSN → Nuclear-powered attack sub
- SSBN → Nuclear-powered Ballistic missile sub (nuclear triad)
Summary (Bottom of Cornell Notes)
> - Missiles: IGMDP (PATNA). Agni-V MIRV (Mission Divyastra). BrahMos (supersonic ramjet JV). > - Air Defense: Two-tier BMD: Exo-atmospheric PAD/PDV (>50km), Endo-atmospheric AAD/Ashwin (<30km). > - Navy: STOBAR carriers (Vikrant, Vikramaditya). P15B destroyers, P17A frigates (integrated mast), P28 ASW corvettes (carbon-fiber). Arihant SSBN (SLBM: K-15/K-4). > - Air/UAV: Prachand LCH (Siachen rated). Netra AEW&C (DRDO radar on Embraer). > - Treaties: iCET & USA Foundational agreements (G-L-C-B: GSOMIA -> LEMOA -> COMCASA -> BECA). MTCR, Wassenaar, Australia Group member (NSG NOT member).
Self-Test Questions
10 Rapid-Fire Recall Questions
- What is the critical range difference between an IRBM and an ICBM?
- Under which mission did India operationalize its first MIRV-capable ballistic missile?
- How does an anti-radiation missile like Rudram target enemy defense grids?
- Identify the two BMD layers and their altitude limits.
- What is the purpose of the Weapon Locating Radar (Swathi)?
- Explain AIP and why it does NOT make a conventional sub "nuclear."
- Name all six Scorpene-class submarines built under Project 75.
- What is the difference between STOBAR and CATOBAR launch systems?
- Which naval project features warships with a carbon-fiber composite superstructure?
- Explain the mnemonic "G-L-C-B" with years.
🎯 UPSC Prelims 2026 Questions & Explanations
| 3. It was developed by TBRL, DRDO in collaboration with the 30th Ce... | - Question 46: 3. It was developed by TBRL, DRDO in collaboration with the 30th Central Scientific Research Institute, Russia. Select the answer using the code given below: (a) 1, 2 and 3 (b) 2 and 3 only (c) 1 and 2 only (d) 1 only X', born in the UK, was conferred the Nobel Prize in 2025. He was a professor in an American university when this prize was announced. Identify 'X': (a) Michel H. Devoret (b) Richard Robson (c) John Clarke (d) Joel Mokyr Correct Answer: () Key Concepts & Explanation: 28). For this purpose, the Bomb Disposal Systems Panel (PGD 28/P1) was constituted under the convenorship of TBRL, DRDO (no CSRI, Russia). Hence sttaement 3 is not correct. The new standard is known as IS 19445:2025 : Hence statement 1 is correct. IS 19445:2025 is the officially designated standard for the testing and evaluation framework of bomb disposal systems. It will improve interoperability of equipment across agencies – Hence statement 2 is correct. Standardization facilitates compatibility and coordinated functioning of equipment among different agencies. eleasePage.aspx ?PRID=2209191 ®=3&lang=1 C This appears to be a repeated question. The 2025 Nobel Prize in Physics was awarded to John Clarke along with other recipients. John Clarke was born in the United Kingdom and was serving as a professor at the University of California, Berkeley at the time of the announcement. He is widely recognized for his contributions to SQUIDs (Superconducting Quantum Interference Devices) and advancements in quantum measurement technologies. Hence option (c) is the correct answer. a. Michel H. Devoret – Incorrect. He was born in France, not in the United Recently, in the news, but the exact background of John Clarke was not widely covered, only his contributio ns were. Year Asked: Prelims 2026 |
| Consider the following statements about Mission Sudarshan Chakra of... | - Question 85: Consider the following statements about Mission Sudarshan Chakra of India: 1. It aims to enhance India's air defence, ballistic missile defence and aerial offensive capabilities. 2. This Mission is being designed to enhance rapid, precise, and powerful defence responses, reinforcing India's strategic autonomy. 3. One of the aims of this Mission is to cover all public places of India by an expanded nationwide security Correct Answer: (A) Key Concepts & Explanation: other Parliamentary Committees has all the powers to call for the detailed information from the Ministries of the Government, Public Undertakings, Nationalised Banks, and various organisations in respect of subjects taken up by the Committee for examination of official and non-official witnesses. Mission Sudarshan Chakra is an initiative of the Indian Air Force (IAF) aimed at strengthening India's integrated air defence network, ballistic missile defence systems, and aerial offensive capabilities. The mission seeks to improve rapid, precise, and effective defense responses while enhancing India's strategic preparedness and self-reliance against evolving security challenges. It is a military initiative focused on national defence and should not be interpreted as a civilian security programme for public spaces. Recently, it was in the news M FCA https://www.pi.b.gov.in/PressRreleasePage.aspx?PRID=2156841®=3&lang=2https://indianexpress.com/article/indigena-indigenous-j-engine-push-modi-i-day-speech-defence-10191305/https://www.pi.b.gov.in/PressRreleasePage.aspx?PRID=2205873®=1&lang=1 EN PT 3652026Internaational/s.is.in/current/affairsn:Article5.3.MissionnSudarharchakra/ann-chakra/chakra-chakra-chakramissionneAugust/vision/as.in/current/https:/vision/assets.in/maganie/2025-04-04/security/udarshan-chakra-mission-news/ Complete Year Asked: Prelims 2026 |
| Which of the following items of defence hardware is/are 1. Su-30 MK... | - Question 93: Which of the following items of defence hardware is/are 1. Su-30 MKI Fighter Jets 2. T-90 MK-III Tanks 3. Akula Class Submarine Select the answer using the code given below: (a) 1 and 2 (b) 1 and 3 (c) 1 only (d) 2 only Su-30 MKI Fighter Jets: Su-30 MKI T-90 MK-III Tanks: T-90 main battle tanks, commonly referred to as Bfishma tanks, are produced in India at the Heavy Vehicles Factory in Avadi under a technology transfer and licensed manufacturing agreement with Russia. Hence statement is 2 correct. Akula Class Submarine: Akula-class nuclear-powered submarines have not been manufactured in India. These submarines have been leased from Russia and operated by the Indian Navy under the name INS Chakra. Hence, this statement is 3 incorrect. Correct Answer: (D) Key Concepts & Explanation: A India has increasingly emphasized domestic defence manufacturing through technology transfer agreements and strategic collaborations with partner countries, Sukhoi jets, the backbone of the IAF, FCA https://indianexpress.com/artice/india/bihar-2-day-family-vacation-govt- EN Vision/ASA IITS 2026: Today (22 April 2026): Weapon systems News /Day (22 April 2026) /Affairs/ particularly Russia. Public sector been in the news employees-3- months- Country of origin Assem news- undertakings such as Hindustan news 10708355/?ref= 1. Ice Breaker missile bly for today/ Aeronautics Limited (HAL) and defence manufacturing units have played a major role in indigenous production of Akula Class was explained in one of the old Indian Express articles, but the recent recurring theme has been the focus on indigenous capabilities. infinite : United States Tanks 2026-04- major role in indigenous production of was https://indianexpress.com/article/explained/exp 2. MQ-9B drone advanced military systems. While several fighter aircraft and armoured vehicles are manufactured in India, certain highly sensitive strategic technologies, such as nuclear-powered attack submarines, have not been fully developed domestically and have instead been obtained through leasing arrangements. the recent recurring theme has been the indigenous lained-indias- submarine- story-in-deep- waters-long- way-to-go/ 3. T-90 Main Battle Tank : Russia airing 22/also the recent recent棘雪业有限公司 the recent recent recurring (a) Only one pair (b) Only two pairs (c) All three pairs (d) None of the pair Tank assemb ly-for-t-72t-90-tanks the recent棘雪业有限公司 multi-role air superiority fighter aircraft are manufactured in India under a licensed production arrangement by Hindustan Aeronautics Limited (HAL). the current怪貴公司 t-72t-90-tanks the current棘雪业有限公司 T-72/T- Year Asked: Prelims 2026 |
High-Yield S&T Rapid Revision: Defence Technology
- Missiles:
- Ballistic: Trajectory-based parabolic missiles like Agni (Agni-V has MIRV & Canister-launch, 3-stage solid fuel) and Prithvi (liquid fuel SRBM) (DRDO).
- Cruise: Flat-trajectory, sea-skimming path-controllable missiles like BrahMos (supersonic Mach 2.8-3.0, ramjet engine, Indo-Russian JV manufactured in India) and Nirbhay (subsonic) (DRDO).
- BVR AAM: Astra (Beyond-Visual-Range Air-to-Air, Mach 4.5+, indigenous DRDO design manufactured by BDL).
- Propulsion: Ramjet engines (powering BrahMos/Akash, needs atmospheric oxygen), and Scramjet technology for hypersonic applications (HSTDV) (DRDO).
- Defence Systems & AWACS:
- Air Defense: Multi-layered grid containing S-400 Triumf (Russia import, 400km range), Akash SAM (indigenous, 25-30km ramjet), Spyder SAM (Israel, quick-reaction), and Project Kusha (indigenous long-range SAM under development).
- AWACS: DRDO Netra AEW&C (hybrid system: Indian DRDO AESA radar on Brazilian Embraer ERJ-145 frame) and Phalcon (Israeli EL/M-2075 radar on Russian Il-76 airframe).
- Navy Platforms:
- Carriers: INS Vikrant (indigenous STOBAR carrier built by CSL) and INS Vikramaditya (ex-Gorshkov, Russian conventional carrier).
- Submarines: SSBN nuclear ballistic (INS Arihant/Arighat, indigenous ATV project built at SBC Vizag); SSK conventional diesel-electric (Kalvari-class, French Scorpène design licensed MDL); SSN nuclear attack (INS Chakra, leased Russian Akula-class, returned).