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Space and Defence Technology
Missiles and Strategic Systems: IGMDP, Agni, BrahMos, BMD and Nuclear Doctrine
IGMDP and the PATNA missiles, Agni series and MIRV, BrahMos, ballistic missile defence, Mission Shakti ASAT, hypersonics, the nuclear triad and doctrine (as of 2026).
Prerequisites
- Indian Space Programme: Evolution, Institutions and Launch Vehicles — a ballistic missile and a satellite launcher share the same rocket science.
- Motion and Force — projectile motion explains why a “ballistic” missile follows an arc.
The Hook: The Missile Man’s Two Careers
Connect
Dr A.P.J. Abdul Kalam led ISRO’s SLV-3, which put Rohini in orbit in 1980. Three years later he moved to the DRDO to lead a new missile programme. The same solid-motor and guidance skills that lift a satellite can also deliver a warhead — which is exactly why the world watches rocket programmes closely, and why India faced technology controls for decades.
How did India build its missiles, what does each one do, and what rules govern their use? Defence technology is now named in the CGPSC syllabus alongside space, so expect both “match the missile” MCQs and Mains questions on self-reliance and deterrence.
Why it matters: Prelims asks the type, range class and range of missiles, and “first” tests (ASAT, MIRV, hypersonic). Mains GS-II asks about indigenisation, deterrence and dual-use technology.
Missile Basics (प्रक्षेपास्त्र)
| Term | Meaning |
|---|---|
| Ballistic missile | Powered only in the initial phase; then follows a free-falling arc (largely outside or high in the atmosphere) to the target. Fast, hard to intercept. Example: Agni, Prithvi |
| Cruise missile | Powered throughout its flight, flies low within the atmosphere like an unmanned aircraft, can change course. Example: BrahMos, Nirbhay |
| Subsonic / supersonic / hypersonic | Speed below Mach 1 / Mach 1–5 / above Mach 5 |
| MIRV | Multiple Independently targetable Re-entry Vehicles — one missile carries several warheads, each aimed at a different target |
| Canisterisation | Missile stored and launched from a sealed tube — quicker launch, easier road/rail mobility |
Range classes (commonly used): short-range (SRBM) up to ~1,000 km · medium-range (MRBM) ~1,000–3,000 km · intermediate-range (IRBM) ~3,000–5,500 km · intercontinental (ICBM) more than ~5,500 km.
IGMDP: Where It Began
The Integrated Guided Missile Development Programme (IGMDP) was launched by the DRDO in 1983, led by Dr A.P.J. Abdul Kalam. It was formally closed in 2008, its missiles having moved into production or follow-on programmes.
| Missile | Type | Status / note |
|---|---|---|
| Prithvi | Surface-to-surface, short-range ballistic, liquid-fuelled | First test 1988; Prithvi-II (~350 km) inducted; naval version Dhanush |
| Agni | Ballistic (began as a technology demonstrator, 1989) | Grew into the strategic Agni series (below) |
| Trishul | Short-range surface-to-air | Did not meet requirements; closed |
| Nag | Third-generation anti-tank, “fire and forget” | Inducted with its carrier vehicle NAMICA; helicopter version Helina/Dhruvastra |
| Akash | Medium-range surface-to-air | Inducted in the Army and Air Force; used in the air defence of Operation Sindoor (May 2025); Akash-NG is the follow-on |
Mnemonic: PATNA
Prithvi · Agni · Trishul · Nag · Akash — the five IGMDP missiles spell the capital of Bihar.
The Agni Series (अग्नि)
| Missile | Class | Approx. range |
|---|---|---|
| Agni-I | SRBM/MRBM | ~700–900 km |
| Agni-II | MRBM | ~2,000 km+ |
| Agni-III | IRBM | ~3,000 km+ |
| Agni-IV | IRBM | ~3,500–4,000 km |
| Agni-V | ICBM-class | 5,000 km+ |
| Agni-Prime (Agni-P) | New-generation MRBM, canisterised | ~1,000–2,000 km |
Key Agni milestones (dated):
- 19 Apr 2012: first test of Agni-V.
- 11 Mar 2024 — Mission Divyastra: first flight test of Agni-V with MIRV technology. India joined the small group of countries with tested MIRV capability. The project was led by a woman scientist, R. Sheena Rani, as programme director.
- September 2025: Agni-Prime launched from a rail-based mobile launcher for the first time.
- 8 May 2026: an advanced Agni missile with MIRV was flight-tested from Dr APJ Abdul Kalam Island (Odisha), with warheads aimed at targets spread over the Indian Ocean region.
Test site: Agni and most long-range missiles are tested from Dr APJ Abdul Kalam Island (earlier Wheeler Island, renamed 2015) off Odisha; shorter-range tests are often from the Integrated Test Range, Chandipur (Odisha).
Cruise Missiles and Other Families
| Missile | Type | Note |
|---|---|---|
| BrahMos (ब्रह्मोस) | Supersonic cruise (about Mach 2.8–3) | India–Russia joint venture BrahMos Aerospace (inter-governmental agreement 1998). Name from the Brahmaputra + Moskva rivers. Launched from land, ship, submarine and aircraft (Su-30MKI). Range raised beyond the original ~290 km after India joined the MTCR (2016). First export: Philippines (deal 2022, first deliveries 2024). Used in Operation Sindoor (May 2025) |
| Nirbhay | Long-range subsonic cruise | Indigenous; its technology feeds the follow-on long-range land-attack cruise missile |
| Pralay | Short-range quasi-ballistic surface-to-surface | Can manoeuvre in flight; conventional warhead |
| Shaurya | Canisterised hypersonic-speed surface-to-surface | Land variant derived from submarine-launched missile tech |
| Astra | Beyond-visual-range air-to-air | Indigenous; on Su-30MKI and Tejas |
| Rudram | Air-launched anti-radiation | Homes onto enemy radar emissions |
| QRSAM, MRSAM, VL-SRSAM | Surface-to-air | Quick-reaction (Army), medium-range (with Israel), vertical-launch short-range (Navy) |
| MPATGM | Man-portable anti-tank | Fire-and-forget, for infantry |
Hypersonic weapons
- HSTDV (Hypersonic Technology Demonstrator Vehicle), Sep 2020: tested an air-breathing scramjet engine.
- 16 Nov 2024: Long-Range Hypersonic Missile (LRHM) flight-tested from Dr APJ Abdul Kalam Island, designed for ranges beyond 1,500 km. India joined the small group of nations with hypersonic missile capability.
Ballistic Missile Defence and Air Defence
| System | What it is |
|---|---|
| Two-tier BMD (DRDO) | Prithvi Air Defence (PAD) interceptor for exo-atmospheric (high-altitude) interception + Advanced Air Defence (AAD) for endo-atmospheric (lower) interception. Phase-II interceptors (for longer-range threats) have been flight-tested since 2022 |
| S-400 Triumf | Long-range air defence bought from Russia (deal 2018; deliveries from 2021). The IAF calls it “Sudarshan Chakra” |
| IACCS | Integrated Air Command and Control System — the IAF network that links radars and weapons |
| IADWS | Integrated Air Defence Weapon System: QRSAM + VSHORADS + a high-power laser directed-energy weapon; first integrated flight test Aug 2025 |
| Mission Sudarshan Chakra | Announced by the Prime Minister on 15 Aug 2025: a nationwide, layered security shield for strategic and civilian sites, to be built by 2035 |
Mission Shakti — India’s anti-satellite (ASAT) test
- 27 Mar 2019: a DRDO interceptor (a BMD PDV Mk-II missile) launched from Dr APJ Abdul Kalam Island destroyed Microsat-R, an Indian satellite in low Earth orbit (~300 km), in a “hit-to-kill” strike.
- India became the fourth country with a demonstrated ASAT capability after the USA, Russia and China.
- The low altitude was chosen so that debris would decay and burn up relatively quickly. India stated it was not aimed at any country and did not violate the Outer Space Treaty (1967), which bans weapons of mass destruction in orbit, not ASAT tests.
The Nuclear Triad and Doctrine
Tests
| Event | Date | Note |
|---|---|---|
| Pokhran-I (“Smiling Buddha”) | 18 May 1974 | Described as a “peaceful nuclear explosion” |
| Pokhran-II (“Operation Shakti”) | 11 and 13 May 1998 | Five tests; India declared itself a nuclear-weapon state. 11 May is National Technology Day |
Triad (थल–जल–नभ)
| Leg | Platform |
|---|---|
| Land | Agni series, Prithvi |
| Air | Fighter aircraft (e.g. Mirage-2000, Su-30MKI, Rafale) |
| Sea | SSBNs (nuclear-powered ballistic missile submarines) with K-series missiles: K-15 (~750 km) and K-4 (~3,500 km) |
SSBN fleet (as of 2026):
- INS Arihant — commissioned 2016 (confirmed publicly later); completed its first deterrence patrol in Nov 2018, which made India’s nuclear triad operational.
- INS Arighaat — commissioned Aug 2024.
- INS Aridhaman — commissioned 3 Apr 2026; larger, with eight missile tubes (twice the first two). Three SSBNs allow one to be on patrol at all times.
Nuclear doctrine (adopted January 2003)
- Credible minimum deterrence (विश्वसनीय न्यूनतम प्रतिरोध).
- No First Use (NFU) — nuclear weapons only in retaliation against a nuclear attack on Indian territory or forces anywhere.
- Retaliation will be massive, designed to inflict unacceptable damage.
- No use against non-nuclear-weapon states.
- Option to retaliate with nuclear weapons against a major biological or chemical attack.
- Control by the Nuclear Command Authority: a Political Council chaired by the Prime Minister (the only body that can authorise use) and an Executive Council chaired by the National Security Adviser. The Strategic Forces Command (2003) manages the weapons.
- Continued moratorium on testing; support for a nuclear-weapon-free world.
Export-control regimes (India’s status)
| Regime | India joined |
|---|---|
| MTCR (Missile Technology Control Regime) | June 2016 |
| Wassenaar Arrangement (conventional arms and dual-use goods) | Dec 2017 |
| Australia Group (chemical and biological) | Jan 2018 |
| Nuclear Suppliers Group (NSG) | Not a member (bid blocked, notably by China) |
| NPT and CTBT | Not signed — India calls them discriminatory |
Memory Tricks
'Bra-Mos = Brahmaputra + Moskva'
BrahMos is Brahmaputra + Moskva: an India–Russia joint venture, supersonic, launched from land, sea, sub-surface and air.
'M-W-A, 16-17-18' for regimes
MTCR 2016 → Wassenaar 2017 → Australia Group 2018. NSG — still no.
Three Ari submarines: 'Hant–Ghaat–Dhaman' = 2016–2024–2026
Arihant (2016) → Arighaat (2024) → Aridhaman (Apr 2026, eight tubes).
Don’t Confuse
| This | vs | That |
|---|---|---|
| Ballistic (Agni, Prithvi) — powered only at first, arc trajectory | vs | Cruise (BrahMos, Nirbhay) — powered throughout, flies low |
| Mission Shakti (2019) — ASAT test | vs | Operation Shakti (1998) — Pokhran-II nuclear tests |
| Mission Divyastra (Mar 2024) — first Agni-V MIRV test | vs | Mission Sudarshan Chakra (Aug 2025) — planned national air-defence shield |
| S-400 “Sudarshan Chakra” — imported Russian system | vs | Akash — indigenous IGMDP surface-to-air missile |
| Political Council (PM) — authorises nuclear use | vs | Executive Council (NSA) — advises and executes |
Common Mistakes
MCQ traps
- “Trishul is an anti-tank missile.” False. Trishul was a short-range surface-to-air missile; Nag is anti-tank.
- “BrahMos is a hypersonic ballistic missile.” False. It is a supersonic cruise missile (a hypersonic version is a separate future project).
- “India’s ASAT test destroyed a foreign satellite.” False. The target was India’s own Microsat-R.
- “India’s nuclear doctrine allows first use against any adversary.” False. The doctrine is No First Use, with an exception for retaliation against major biological or chemical attacks.
- “India is a member of the NSG.” False. It is in MTCR, Wassenaar and the Australia Group — not the NSG.
Practice
All questions below are original practice questions written in CGPSC style. They are not previous-year questions.
Level 1: Foundation
- IGMDP was launched in the year ______ under Dr A.P.J. Abdul Kalam.
- The Agni-V test with MIRV technology in March 2024 was named Mission ______.
- India’s ASAT test of March 2019 was called Mission ______.
Answers
- 1983.
- Divyastra.
- Shakti.
Level 2: Prelims MCQs
Q1. Consider the following statements:
- BrahMos is a supersonic cruise missile developed jointly by India and Russia.
- Nag is a surface-to-air missile developed under IGMDP.
- Agni-Prime is a canisterised missile.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 1 and 3 only
- (c) 2 and 3 only
- (d) 1, 2 and 3
Answer and explanation
(b) 1 and 3 only. Nag is an anti-tank guided missile; Akash and Trishul were the IGMDP surface-to-air missiles. BrahMos is the India–Russia supersonic cruise missile, and Agni-Prime is a new-generation canisterised ballistic missile.
Q2. Match List I (Missile) with List II (Category):
| List I | List II |
|---|---|
| A. Astra | 1. Anti-radiation |
| B. Rudram | 2. Air-to-air, beyond visual range |
| C. K-4 | 3. Submarine-launched ballistic |
| D. Nirbhay | 4. Subsonic cruise |
- (a) A-2, B-1, C-3, D-4
- (b) A-1, B-2, C-3, D-4
- (c) A-2, B-1, C-4, D-3
- (d) A-2, B-3, C-1, D-4
Answer and explanation
(a) A-2, B-1, C-3, D-4. Astra is the indigenous BVR air-to-air missile; Rudram homes onto enemy radar; K-4 is the ~3,500 km SLBM for the Arihant class; Nirbhay is a long-range subsonic cruise missile.
Q3. With reference to India’s nuclear doctrine (2003), which one of the following is not correct?
- (a) It is based on credible minimum deterrence.
- (b) Nuclear retaliation can be authorised only by the Political Council of the Nuclear Command Authority.
- (c) It permits first use of nuclear weapons against a non-nuclear-weapon state that hosts foreign troops.
- (d) India retains the option of nuclear retaliation against a major biological or chemical attack.
Answer and explanation
(c) is not correct. The doctrine commits to No First Use and no use against non-nuclear-weapon states. The other three statements reflect the 2003 doctrine.
Q4. India became the fourth country to demonstrate which of the following capabilities in 2019?
- (a) MIRV-equipped ICBM
- (b) Anti-satellite strike against a satellite in low Earth orbit
- (c) Hypersonic cruise missile
- (d) Submarine-launched ballistic missile
Answer and explanation
(b). Mission Shakti (27 Mar 2019) destroyed Microsat-R in LEO, after the USA, Russia and China. MIRV (Divyastra) came in 2024 and the long-range hypersonic missile test in Nov 2024.
Level 3: Mains Answer Writing
Q1. (150–200 words) Explain the significance of India’s nuclear triad and its No First Use doctrine.
Model answer outline
- Intro: Pokhran-II (1998) → doctrine (2003) of credible minimum deterrence and NFU.
- Triad: land (Agni series, Agni-V MIRV 2024 and 2026 tests), air (fighter-delivered), sea (SSBNs Arihant, Arighaat, Aridhaman with K-15/K-4). Arihant’s first deterrence patrol (Nov 2018) made the triad operational.
- Why the sea leg matters: submarines are the most survivable — essential for a NFU state, which must absorb a first strike and still retaliate (assured second strike).
- NFU benefits: stability, moral standing, supports India’s case for NSG membership and its record as a responsible power; low arms-race pressure.
- Debates: calls to review NFU, two-front threat, MIRV and hypersonic developments in the region.
- Conclusion: A survivable triad makes NFU credible — restraint backed by capability.
Q2. (100 words) What is a hypersonic missile? Why is it hard to defend against?
Model answer outline
- Definition: flies faster than Mach 5; either a boost-glide vehicle or a scramjet-powered cruise missile.
- Hard to stop: speed cuts reaction time; flies lower than ballistic missiles (late radar detection) and manoeuvres, so its path cannot be predicted.
- India: HSTDV scramjet test (2020); LRHM flight test (16 Nov 2024), range beyond 1,500 km.
- Conclusion: Hypersonics push defence towards space-based sensors and directed-energy weapons.
Quick Revision Table
| Fact | Detail |
|---|---|
| IGMDP | 1983–2008; Kalam; Prithvi, Agni, Trishul, Nag, Akash (PATNA) |
| Prithvi-II | ~350 km, liquid; naval: Dhanush |
| Agni-V | 5,000 km+; first test 19 Apr 2012 |
| Mission Divyastra | 11 Mar 2024; Agni-V MIRV |
| Agni-Prime | Canisterised; rail-launch Sep 2025 |
| Advanced Agni MIRV test | 8 May 2026, Kalam Island |
| BrahMos | India–Russia; Brahmaputra + Moskva; supersonic cruise; Philippines first export |
| LRHM | Hypersonic, 16 Nov 2024, >1,500 km |
| Mission Shakti | ASAT, 27 Mar 2019, Microsat-R, ~300 km; 4th country |
| Two-tier BMD | PAD (exo) + AAD (endo) |
| S-400 | Russia; IAF name “Sudarshan Chakra” |
| Mission Sudarshan Chakra | Announced 15 Aug 2025; shield by 2035 |
| Pokhran-I / II | 18 May 1974 / 11 and 13 May 1998 |
| Nuclear doctrine | Jan 2003; CMD, NFU, NCA (PM / NSA) |
| SSBNs | Arihant (2016), Arighaat (Aug 2024), Aridhaman (3 Apr 2026) |
| Regimes | MTCR 2016, Wassenaar 2017, Australia Group 2018; not NSG |
| Test sites | Dr APJ Abdul Kalam Island (ex-Wheeler) and Chandipur, Odisha |
Key Takeaways
Key Takeaways
- IGMDP (1983) gave India its missile base — remember PATNA.
- Ballistic vs cruise is the first distinction; BrahMos is supersonic cruise, Agni is ballistic.
- Recent capability firsts: ASAT (2019), MIRV (2024), long-range hypersonic (2024); a third SSBN in 2026.
- India’s NFU doctrine (2003) depends on a survivable triad, especially the sea leg.
- India is in MTCR, Wassenaar and the Australia Group but not the NSG.
What’s Next
- Defence Technology and Indigenisation — aircraft, ships, DRDO and self-reliance in defence
- Space Exploration and Human Spaceflight — the civilian use of the same rocket science
- International Organisations and Events — arms-control regimes and India’s diplomacy
- Union Executive — the Prime Minister’s role, including in the Nuclear Command Authority
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