Ballistic Missile vs. Cruise Missile, India’s Missile Systems, IGMDP

We frequently notice news related to ballistic missiles, cruise missiles and various missile systems of India. Memorizing names and salient features of various Indian missiles is hard without having a broader understanding of the concept of ballistic missiles and cruise missiles, and major missile defence systems. It is better to give these concepts a holistic structure rather than learning them in bits and pieces.

Ballistic Missile vs. Cruise Missile

The Hindu | GS3 > indigenization of technology

The terms ‘ballistic missile’ and ‘cruise missile’ appear in news articles wherever there is a missile test. It is essential for us to understand these terms to understand various Indian missile defence systems.

Ballistic Missile

• A ballistic missile follows a ballistic trajectory to deliver one or more warheads on a predetermined target.
• A ballistic trajectory is the path of an object that is launched but has no active propulsion during its actual flight (these weapons are guided only during relatively brief periods of flight).
• Consequently, the trajectory is fully determined by a given initial velocity, effects of gravity, air resistance, and motion of the earth (Coriolis Force).

Image Credits: Wikipedia

• Shorter range ballistic missiles stay within the Earth’s atmosphere.
• Longer-ranged intercontinental ballistic missiles (ICBMs), are launched on a sub-orbital flight trajectory and spend most of their flight out of the atmosphere.

Types of ballistic missiles based on the range

• Short-range (tactical) ballistic missile (SRBM): Range between 300 km and 1,000 km.
• Medium-range (theatre) ballistic missile (MRBM): 1,000 km to 3,500 km.
• Intermediate-range (Long-Range) ballistic missile (IRBM or LRBM): 3,500 km and 5,500 km.
• Intercontinental ballistic missile (ICBM): 5,500 km +

Cruise missile

• A cruise missile is a guided missile (target has to be pre-set) used against terrestrial targets.
• It remains in the atmosphere throughout its flight.
• It flies the major portion of its flight path at approximately constant speed.
• Cruise missiles are designed to deliver a large warhead over long distances with high precision.
• Modern cruise missiles are capable of travelling at supersonic or high subsonic speeds, are self-navigating, and are able to fly on a non-ballistic, extremely low-altitude trajectory.

Types of cruise missiles based on speed

• Hypersonic (Mach 5): these missiles would travel at least five times the speed of sound (Mach 5). E.g. BrahMos-II.
• Supersonic (Mach 2-3): these missiles travel faster than the speed of sound. E.g. BrahMos.
• Subsonic (Mach 0.8): these missiles travel slower than the speed of sound. E.g. Nirbhay.

Differences between Ballistic Missile and Cruise Missile

Ballistic Missile	Cruise Missile
It is propelled only for a brief duration after the launch.	Self-propelled till the end of its flight.
Similar to a rocket engine.	Similar to a jet engine.
Long-range missiles leave the earth’s atmosphere and reenter it.	The flight path is within the earth’s atmosphere.
Low precision as it is unguided for most of its path and its trajectory depends on gravity, air resistance and Coriolis Force.	Hits targets with high precision as it is constantly propelled.
Can have a very long range (300 km to 12,000 km) as there is no fuel requirement after its initial trajectory.	The range is small (below 500 km) as it needs to be constantly propelled to hit the target with high precision.
Heavy payload carrying capacity.	Payload capacity is limited.
Can carry multiple payloads (Multiple Independently targetable Re-entry Vehicle)	Usually carries a single payload.
Developed primarily to carry nuclear warheads.	Developed primarily to carry conventional warheads.
E.g. Prithvi I, Prithvi II, Agni I, Agni II and Dhanush missiles.	E.g. BrahMos missiles

Integrated Guided Missile Development Programme (IGMDP)

PIB | Source | The Hindu | 19-06-2019 | GS3 > indigenization of technology

• IGMDP was conceived by Dr. A P J Abdul Kalam to enable India attain self-sufficiency in missile technology.
• IGMDP was conceived in response to the Missile Technology Control Regime that decided to restrict access to any technology that would help India in its missile development program.
• To counter the MTCR, the IGMDP team formed a consortium of DRDO laboratories, industries and academic institutions to build these sub-systems, components and materials.

Missile Technology Control Regime (MTCR) MTCR an informal grouping established in 1987 by Canada, France, Germany, Italy, Japan, the United Kingdom and the United States to limit the proliferation of missiles and missile technology. The MTCR seeks to limit the risks of proliferation of weapons of mass destruction (WMD). MTCR places particular focus on rockets and unmanned aerial vehicles capable of delivering a payload of at least 500 kg to a range of at least 300 km. The MTCR is not a treaty and does not impose any legally binding obligations.

• IGMDP was started in 1983 and completed in March 2012.
• Keeping in mind the requirements of various types of missiles by the defence forces, the development of five missile systems was taken up.

1. Prithvi: Short-range surface-to-surface ballistic missile (Prithivi means Earth Surface to Surface)
2. Agni: Intermediate-range surface-to-surface ballistic missile
3. Trishul: Short-range low-level surface-to-air missile
4. Akash: Medium-range surface-to-air missile (Akash means Sky Surface to Air)
5. Nag: Third generation anti-tank missile (Nag means Snake Nag slithers like a Snake to hit a tank!)

• After its success, the Agni missile program was separated from the IGMDP upon realizing its strategic importance.

India’s Missile Systems

PIB | Source | The Hindu | GS3 > indigenization of technology

Missile	Type		Range
Astra	air-to-air		80 km
Trishul	surface-to-air		9 km
Akash			30 km
Prithvi Air Defence (PAD)			2000 km
Nag	surface-to-surface Anti-tank missile		4 km
Prahaar	surface-to-surface	SRBM	150 km
BrahMos	land, naval, air	Supersonic Cruise Missile	300 km
Nirbhay	land, naval, air	Subsonic Cruise Missile	1000 km
K-15 Sagarika	underwater-to-surface	SLBM	700 km
Dhanush	sea-to-sea/surface	SRBM	350 km
Shaurya	surface-to-surface	SLBM	1900

SLBM: Sub-marine launched ballistic missile

Missile	Features
Astra	Astra is a beyond-visual-range (BVR) air-to-air missile (AAM). In terms of size and weight, the Astra is the smallest missile developed by the DRDO. It was envisaged to intercept and destroy enemy aircraft at supersonic speeds.
Trishul	Used as anti-sea skimmer (to fly low to avoid radar) from ships against low-flying attacks.
Akash	It has the capability to “neutralize aerial targets like fighter jets, cruise missiles and air-to-surface missiles” as well as ballistic missiles.
PAD	Anti-ballistic missile developed to intercept incoming ballistic missiles outside the atmosphere (exo-atmospheric).
Nag	3rd generation anti-tank ‘fire and forget’ guided missile (lock-on before launch system) where the target is identified and designated before the weapon is launched.
Prahaar	High manoeuvrability. Primarily a battlefield support system for the Army.
BrahMos	It is a supersonic cruise missile developed as a joint venture between Indian and Russia. It is the fastest supersonic cruise missile in the world. It is the world’s fastest anti-ship cruise missile in operation.
Nirbhay	Subsonic missile which is ancillary (providing necessary support) to the BrahMos range.
K-15 Sagarika	It forms the crucial third leg of India’s nuclear deterrent vis-à-vis its submarine-launched ballistic missile (SLBM) capability. It was subsequently integrated with India’s nuclear-powered Arihant class submarine.
Dhanush	It is capable of carrying nuclear warheads. It carries forward the legacy of the K-15 Sagarika.
Shaurya	Surface-to-surface ballistic missile (SSM) variant of the K-15 Sagarika. The nuclear capability of the missile enhances India’s second-strike capability. It reduces the dependence on the K-15 which was built with Russian assistance.

Prithvi Missiles

All the Prithvi variants are surface-to-surface SRBMs.

Name	Version	Range	Payload in kg
Prithvi I	Army version	150 km	1000
Prithvi II	Air force version	350 km	500
Prithvi III	Naval version	600 km	1000

Agni Missiles

Name	Type	Range	Payload in kg
Agni-I	MRBM	700 – 900 km	1,000
Agni-II	MRBM	2,000 – 3,000 km	750 – 1,000
Agni-III	IRBM	3,500 – 5,000 km	2,000 – 2,500
Agni-IV	IRBM	3,000 – 4,000  km	800 – 1,000
Agni-V	ICBM	5,000 – 8,000 km (Testing)	1,500 (3 – 10 MIRV)
Agni-VI	ICBM	8,000 – 10,000 km (Under development)	1,000 (10 MIRV)

MIRV: Multiple Independently targetable Re-entry Vehicle

Anti-satellite weapons (ASAT)

• In March 2019, India successfully tested its ASAT missile.
• The ASAT missile destroyed a live satellite in Low Earth orbit (283-kilometre).
• As per DRDO, the missile is capable of shooting down targets moving at a speed of 10 km per second at an altitude as high as 1200 km.