Topic 16: Defence Technology — Missiles, Aircraft, Nuclear Triad & Self-Reliance

This file is a complete GS-III account of India's defence technology. It explains missiles & their types (ballistic vs cruise — Agni, Prithvi, BrahMos), the IGMDP, missile & air defence (BMD, S-400, Akash, QRSAM), military aircraft (Tejas LCA, AMCA, HAL), naval systems & the nuclear triad (INS Vikrant, INS Arihant), land systems & artillery, DRDO & the defence R&D ecosystem, Atmanirbhar defence production (DPSUs, defence corridors, exports) and emerging warfare (hypersonics, drones, directed-energy, cyber & space) — with labelled diagrams, tables and real dated PYQs with full model answers. (Nuclear science is in Topic 15; space in Topics 8–9.)

UPSC Prelims · Mains GS-III Missiles · Aircraft ~35 min read DRDO & Atmanirbhar High CA Weight

1.Missiles & Missile Types
2.IGMDP & India's Missiles
3.Missile & Air Defence
4.Military Aircraft
5.Naval Systems & Nuclear Triad
6.Land Systems & Artillery
7.DRDO & Defence R&D
8.Self-Reliant Defence Production
9.Emerging Warfare Technologies
10.Current Affairs Link
11.Prelims PYQs
12.Mains PYQs + Model Answers
★15-Minute Revision Box

Conceptual Clarity — How UPSC Tests Defence Technology

This is a fact- & current-heavy area with strong strategic weight (self-reliance, security). Sort your prep into three question-types:

Definitional / static — "ballistic vs cruise missile?", "what is the nuclear triad?", "what is BMD?". Recall of concepts & systems.
Statement-elimination — missile ranges & names, aircraft/ship facts, DRDO labs where one detail decides the answer.
Applied / current — a system tested/inducted in the news (Agni, BrahMos, Tejas, Arihant, S-400) linked to a fundamental — the strong GS-III security & Atmanirbhar bridge.

Highest-frequency themes: ballistic vs cruise & Agni/BrahMos · IGMDP · BMD & S-400 · Tejas & AMCA · nuclear triad & Arihant · DRDO · Atmanirbhar defence & exports · hypersonics & drones.

1. Missiles & Missile Types

Fig 16.1 — A ballistic missile is powered briefly then follows a high arcing free-fall trajectory (long range, e.g. Agni); a cruise missile flies low & level under continuous propulsion & guidance (precise, e.g. BrahMos).

Ballistic missile: boosted by rockets, then follows a high, arcing free-fall (ballistic) path; classified by range — SRBM, MRBM, IRBM, ICBM. Carries warheads over long distances (e.g. Agni).
Cruise missile: flies low & level like a small jet, self-propelled & continuously guided to a precise target; can be subsonic, supersonic (BrahMos) or hypersonic.
By launch platform: surface-to-surface, surface-to-air, air-to-air, anti-tank, anti-ship; from land, air, ship or submarine.
MIRV = one missile carrying multiple independently targetable warheads (India demonstrated this with Agni-V/Mission Divyastra).

Prelims facts: ballistic = high arc + free-fall (long range, Agni); cruise = low, level, guided (precise, BrahMos, supersonic); ICBM > IRBM > MRBM > SRBM by range; MIRV = multiple warheads on one missile (Agni-V, Mission Divyastra).

2. IGMDP & India's Missiles

The Integrated Guided Missile Development Programme (IGMDP) (1983, led by Dr APJ Abdul Kalam) developed five missiles: Prithvi, Agni, Akash, Trishul & Nag.
Agni series = surface-to-surface ballistic missiles of rising range (Agni-I to Agni-V/Prime); Agni-V is intercontinental-class with MIRV capability.
Prithvi = short-range surface-to-surface ballistic; Akash = surface-to-air; Nag/Helina = anti-tank; Trishul = short-range SAM.
BrahMos = supersonic cruise missile (India–Russia joint venture), the fastest in service; K-series (K-15/K-4) = submarine-launched ballistic missiles for the triad.

Missile	Type	Note
Agni-V	ICBM-class ballistic	MIRV (Divyastra)
Prithvi	SRBM	Surface-to-surface
BrahMos	Supersonic cruise	India–Russia JV
Akash	Surface-to-air	Air defence
K-4	SLBM	Submarine-launched

Prelims traps: IGMDP (Kalam, 1983) = Prithvi, Agni, Akash, Trishul, Nag; Agni = ballistic (long range), BrahMos = supersonic cruise (India–Russia); Akash = SAM; K-series = SLBM (sea leg of the triad).

3. Missile & Air Defence

Ballistic Missile Defence (BMD): India's indigenous two-tier shield — PAD/AAD (Prithvi Air Defence for exo-atmospheric & Advanced Air Defence for endo-atmospheric interception) to destroy incoming ballistic missiles.
S-400 Triumf = long-range Russian air-defence system inducted by India — tracks & shoots down aircraft, drones & missiles at long range.
Indigenous SAMs: Akash & QRSAM (Quick Reaction SAM) for battlefield air defence; Project Kusha = a future long-range indigenous BMD.

Prelims facts: India's indigenous BMD is a two-tier system (PAD exo- + AAD endo-atmospheric); the S-400 is a Russian long-range air-defence system; Akash & QRSAM are indigenous SAMs; Project Kusha is a planned indigenous long-range air-defence shield.

4. Military Aircraft & Aeronautics

Tejas (LCA — Light Combat Aircraft) = India's indigenous fighter, developed by ADA/HAL; Tejas Mk-1A & Mk-2 are upgraded variants.
AMCA (Advanced Medium Combat Aircraft) = India's planned fifth-generation stealth fighter.
HAL (Hindustan Aeronautics Ltd) makes fighters, helicopters (Dhruv, Prachand LCH, Rudra) & trainers; India also operates Rafale, Su-30MKI etc.
Force multipliers: AEW&C (Netra), aerial refuelling, UAVs & the Kaveri indigenous jet-engine effort (a persistent gap — India still imports engines).

Prelims traps: Tejas = indigenous LCA (HAL/ADA); AMCA = future 5th-gen stealth fighter; Prachand (LCH) & Dhruv are HAL helicopters; the jet-engine (Kaveri) remains India's key technology gap driving co-development deals.

5. Naval Systems & the Nuclear Triad

Aircraft carriers: INS Vikrant = India's first indigenously built aircraft carrier (IAC-1); INS Vikramaditya is the other carrier.
Submarines: conventional (Kalvari/Scorpene class, Project-75) & nuclear — INS Arihant is India's first indigenous nuclear-powered ballistic-missile submarine (SSBN).
Nuclear triad = ability to deliver nuclear weapons from land (Agni), air (fighter-dropped) & sea (SLBMs on Arihant) — India completed the triad with Arihant, giving assured second-strike (credible minimum deterrence + No First Use).
Indigenous destroyers/frigates (Visakhapatnam, Nilgiri classes) & the Coast Guard bolster maritime security.

Prelims facts: INS Vikrant = first indigenous aircraft carrier; INS Arihant = first indigenous nuclear-powered submarine (SSBN); the nuclear triad = land + air + sea delivery, giving a survivable second-strike that underpins India's No First Use doctrine.

6. Land Systems & Artillery

Main battle tanks: Arjun (indigenous MBT) alongside T-90 & T-72; a future ready combat vehicle programme is planned.
Artillery: Dhanush & ATAGS (Advanced Towed Artillery Gun System) are indigenous howitzers; Pinaka = multi-barrel rocket launcher.
Small arms: INSAS being replaced by newer rifles; indigenous production is expanding.

GS-III hook: land systems (Arjun, ATAGS, Pinaka) exemplify the shift to indigenous design & manufacture — reducing import dependence, building a domestic industrial base & enabling exports under Atmanirbhar Bharat.

7. DRDO & the Defence R&D Ecosystem

DRDO (Defence Research & Development Organisation) is India's premier defence R&D body (under the Ministry of Defence), with a network of labs (e.g. ADE, DRDL, ADA) developing missiles, radars, aircraft, armour & electronic warfare.
DRDO drove IGMDP, Agni, BrahMos co-development, Tejas, BMD, Arihant's reactor & more.
Partners: DPSUs (HAL, BEL, BDL, BEML, the new Ordnance Factory corporations), private industry & academia (iDEX for start-ups).

Prelims facts: DRDO (under MoD) leads defence R&D — missiles, radars, aircraft; key DPSUs include HAL (aircraft), BEL (electronics) & BDL (missiles); iDEX funds defence start-ups & innovation.

8. Self-Reliant (Atmanirbhar) Defence Production

India has long been a top arms importer; policy now pushes indigenisation via positive indigenisation lists (items barred from import), higher domestic procurement (Buy Indian), FDI liberalisation & the DAP (Defence Acquisition Procedure).
Two defence industrial corridors (Uttar Pradesh & Tamil Nadu) anchor manufacturing clusters; iDEX & Technology Development Fund back start-ups & MSMEs.
Defence exports have risen sharply (BrahMos to the Philippines, other systems), aiming for a large export target — a mark of growing capability.

GS-III hook: self-reliance in defence is both strategic (autonomy, secure supply in conflict) & economic (jobs, exports, technology base). Tools: positive indigenisation lists, defence corridors, iDEX, FDI & the DAP — but jet engines, sensors & some critical tech remain import-dependent.

9. Emerging Warfare Technologies

Hypersonic weapons (>Mach 5, manoeuvring) — India is developing hypersonic tech (HSTDV) & glide vehicles.
Drones/UAVs & loitering munitions — ISR & strike; swarm drones & counter-drone systems are priorities (Topic 13 link).
Directed-energy weapons (lasers/high-power microwaves), electronic & cyber warfare, and space-based ISR (with the Defence Space Agency; Mission Shakti demonstrated ASAT).
AI in defence — autonomous systems, decision support & the debate over lethal autonomous weapons.

GS-III hook: future warfare is shifting to hypersonics, drones & swarms, directed-energy, cyber & space — blurring the lines between domains. India's edge depends on indigenous R&D (DRDO, iDEX), integration across services (theatre commands) & keeping pace with AI-driven autonomy.

10. Current Affairs Link (2024–2026)

Defence tests, inductions & deals are frequent, high-value exam material. Verify the latest before the exam. check for latest update or data

Missile tests: Agni-Prime/Agni-V MIRV (Mission Divyastra) & BrahMos variants apply Sections 1–2. check for latest update or data

Inductions: Tejas Mk-1A deliveries, INS Vikrant operations & new submarines apply Sections 4–5. check for latest update or data

Atmanirbhar & exports: new indigenisation lists, defence-export milestones & corridor investments apply Section 8. check for latest update or data

Recent theme	Fundamental it tests	Why it matters for UPSC
Agni-V MIRV	Missiles / deterrence	GS-III strategic capability.
Tejas / AMCA	Military aircraft	GS-III self-reliance.
Defence exports	Production	GS-III Atmanirbhar & economy.
Drones / hypersonics	Emerging warfare	GS-III future security.

Recurring exam hooks: ballistic vs cruise & Agni/BrahMos · IGMDP · BMD & S-400 · Tejas/AMCA · nuclear triad & Arihant · DRDO · Atmanirbhar & exports · hypersonics/drones.

11. Prelims PYQs

Objective questions anchored to genuinely tested UPSC themes on defence technology. Each carries a worked rationale.

UPSC Prelims — Missile types

Q: BrahMos is best described as a —

(a) long-range ballistic missile
(b) supersonic cruise missile
(c) surface-to-air missile
(d) anti-tank missile

Answer: (b) BrahMos is a supersonic cruise missile (India–Russia joint venture); Agni is the long-range ballistic missile; Akash is a surface-to-air missile.

UPSC Prelims — Ballistic vs cruise

Q: Which statement about ballistic and cruise missiles is correct?

(a) A cruise missile follows a high arcing free-fall path
(b) A ballistic missile is powered briefly then free-falls; a cruise missile is self-propelled and guided throughout
(c) Both fly at very high altitude only
(d) Ballistic missiles cannot carry nuclear warheads

Answer: (b) A ballistic missile is boosted then follows a ballistic (free-fall) arc; a cruise missile flies low and level under continuous propulsion and guidance.

UPSC Prelims — IGMDP

Q: The Integrated Guided Missile Development Programme did NOT include which missile?

(a) Prithvi
(b) Agni
(c) Akash
(d) BrahMos

Answer: (d) IGMDP (1983, Kalam) produced Prithvi, Agni, Akash, Trishul & Nag; BrahMos is a separate later India–Russia joint venture.

UPSC Prelims — Nuclear triad

Q: India's "nuclear triad" refers to the ability to deliver nuclear weapons from —

(a) land only
(b) land and air only
(c) land, air and sea
(d) space

Answer: (c) The triad = delivery from land (Agni), air (fighters) & sea (SLBMs on INS Arihant), giving an assured second-strike capability.

UPSC Prelims — Indigenous carrier

Q: India's first indigenously built aircraft carrier is —

(a) INS Vikramaditya
(b) INS Vikrant
(c) INS Arihant
(d) INS Kalvari

Answer: (b) INS Vikrant (IAC-1) is India's first indigenously built aircraft carrier; Arihant is a nuclear submarine; Kalvari is a conventional submarine.

UPSC Prelims — Indigenous fighter

Q: Tejas is India's indigenous —

(a) Light Combat Aircraft
(b) main battle tank
(c) ballistic missile
(d) submarine

Answer: (a) Tejas is the indigenous Light Combat Aircraft (LCA) by HAL/ADA; Arjun is the indigenous tank; AMCA is the planned 5th-gen fighter.

UPSC Prelims — Air defence

Q: The S-400 Triumf inducted by India is a —

(a) fighter aircraft
(b) long-range air-defence (surface-to-air) system
(c) submarine
(d) tank

Answer: (b) The S-400 is a Russian long-range air-defence system that tracks & shoots down aircraft, drones & missiles; Akash & QRSAM are indigenous SAMs.

UPSC Prelims — DRDO

Q: Which agency is India's premier defence research & development organisation?

(a) ISRO
(b) BARC
(c) DRDO
(d) CSIR

Answer: (c) DRDO (under the Ministry of Defence) leads defence R&D; ISRO is space, BARC is atomic energy, CSIR is civilian scientific research.

Prelims — anticipated themes

Likely: ballistic vs cruise & Agni-V MIRV · IGMDP list · BMD/S-400/Akash · Tejas/AMCA & HAL · nuclear triad & Arihant/Vikrant · DRDO/DPSUs · positive indigenisation & exports · hypersonics/drones. check for latest update or data

12. Mains PYQs + Model Answers

Defence technology anchors GS-III questions on security, self-reliance & strategy. The frameworks below show how to deploy it analytically.

Mains GS-III 15 marks · 250 words

Q: Discuss the significance of self-reliance (Atmanirbhar Bharat) in defence production and the challenges India faces.

Model Answer

Introduction: Long a top arms importer, India is pursuing indigenous defence production (Section 8) for strategic autonomy & economic gain.
Significance:
- Strategic — secure supply in conflict, no external leverage; economic — jobs, technology base & rising exports; capability — systems like Tejas, Arjun, BrahMos, Arihant.
Enablers: positive indigenisation lists, defence corridors, iDEX, FDI reform & the DAP.
Challenges: jet-engine & critical-component gaps, R&D funding, slow procurement, quality/time overruns, private-sector participation.
Way forward: deeper R&D, academia–industry–start-up linkages, co-development & export focus.
Conclusion: self-reliance is essential for India's security & great-power aspirations.

Mains GS-III 15 marks · 250 words

Q: What is the nuclear triad? Explain how completing it strengthens India's strategic deterrence.

Model Answer

Introduction: The nuclear triad (Section 5) is the capacity to deliver nuclear weapons from land, air & sea.
India's triad:
- Land — Agni missiles; air — fighter-dropped weapons; sea — SLBMs on INS Arihant (completed the triad).
Why it matters: the sea leg is the most survivable → assured second-strike, making India's No First Use & credible-minimum-deterrence doctrine believable.
Challenges: more SSBNs, longer-range SLBMs, secure command & control.
Conclusion: a complete, survivable triad underpins strategic stability & deterrence.

Mains GS-III 10 marks · 150 words

Q: How is emerging technology transforming the nature of warfare? Illustrate India's response.

Model Answer

Introduction: Warfare (Section 9) is shifting to new domains — hypersonics, drones, cyber & space.
Transformations:
- Hypersonic & precision strike, drone swarms & loitering munitions, directed-energy, cyber & electronic warfare, AI-enabled autonomy, space-based ISR.
India's response: DRDO programmes (HSTDV), iDEX start-ups, Defence Space Agency, counter-drone systems & theatre commands.
Conclusion: staying ahead needs indigenous R&D, integration & ethical AI frameworks.

Mains GS-III 15 marks · 250 words

Q: Evaluate the role of DRDO in building India's defence capability. What reforms are needed?

Model Answer

Introduction: DRDO (Section 7) is the backbone of India's indigenous defence R&D.
Achievements:
- IGMDP, Agni & BrahMos, Tejas, BMD, Arihant's reactor, radars & electronic warfare.
Concerns: time & cost overruns, technology gaps (engines), limited private/industry linkage, product-vs-research balance.
Reforms: greater industry & start-up (iDEX) partnership, project accountability, focus on core research, global co-development.
Conclusion: a reformed DRDO is central to Atmanirbhar defence & strategic autonomy.

Mains GS-III — anticipated themes

Likely: Atmanirbhar defence & exports · nuclear triad & deterrence · emerging warfare (drones/hypersonics/cyber) · DRDO reform · theatre commands & integration. check for latest update or data

15-Minute Revision Box

Must-Remember Facts — Defence Technology

Missiles:

Ballistic = high arc/free-fall (Agni); Cruise = low/guided (BrahMos, supersonic)
IGMDP (Kalam, 1983): Prithvi, Agni, Akash, Trishul, Nag
Agni-V = ICBM-class + MIRV (Divyastra); K-series = SLBM
Range: ICBM > IRBM > MRBM > SRBM

Air defence & aircraft:

BMD = PAD (exo) + AAD (endo); S-400 = Russian long-range SAM
Akash/QRSAM = indigenous SAMs; Project Kusha future
Tejas = indigenous LCA (HAL); AMCA = 5th-gen stealth
Engine (Kaveri) = key gap

Naval & land:

INS Vikrant = first indigenous carrier; INS Arihant = first SSBN
Triad = land + air + sea → second-strike (No First Use)
Arjun (tank), ATAGS/Dhanush (artillery), Pinaka (MBRL)

Ecosystem & future:

DRDO (MoD) leads R&D; DPSUs: HAL/BEL/BDL; iDEX for start-ups
Atmanirbhar: positive lists, 2 corridors, exports rising
Emerging: hypersonics, drones/swarms, directed-energy, cyber & space

Highest-frequency themes: ballistic vs cruise & Agni/BrahMos · IGMDP · BMD/S-400 · Tejas/AMCA · triad & Arihant/Vikrant · DRDO · Atmanirbhar & exports · hypersonics/drones.

Item	Note
S-400	Russian SAM
Vikrant	First indigenous carrier
DRDO	Defence R&D
iDEX	Defence start-ups

Item	Value
IGMDP	1983, Kalam
Agni-V	MIRV (Divyastra)
Triad	Land+Air+Sea
Corridors	UP & TN

Topic 16: Defence Technology — Missiles, Aircraft, Nuclear Triad & Self-Reliance

On this page

Conceptual Clarity — How UPSC Tests Defence Technology

1. Missiles & Missile Types

2. IGMDP & India's Missiles

3. Missile & Air Defence

4. Military Aircraft & Aeronautics

5. Naval Systems & the Nuclear Triad

6. Land Systems & Artillery

7. DRDO & the Defence R&D Ecosystem

8. Self-Reliant (Atmanirbhar) Defence Production

9. Emerging Warfare Technologies

10. Current Affairs Link (2024–2026)

11. Prelims PYQs

12. Mains PYQs + Model Answers

Model Answer

Model Answer

Model Answer

Model Answer

15-Minute Revision Box

Must-Remember Facts — Defence Technology