What are Ballistic Missiles? How They Work and Where They Can Target – Mechanism Explained

Ballistic missiles are a type of missile that uses projectile motion to deliver explosive materials (warhead) from the launch site to their aimed target. 

These airborne ranged weapons can be launched from aircraft, ships, and submarines in addition to land-based silos and mobile platforms. There are various types, categorised by their range. 

These include Tactical Ballistic Missiles (TBMs), Short-Range Ballistic Missiles (SRBMs), Medium-Range Ballistic Missiles (MRBMs), Intermediate-Range Ballistic Missiles (IRBMs), and Intercontinental Ballistic Missiles (ICBMs). Each type is designed for different engagement distances, from less than 300 km to over 5,500 km. 

In this article, we'll take a closer look at how these powerful weapons work, their different stages of flight, and the sophisticated mechanisms that allow them to strike targets across vast distances.

What are Ballistic Missiles? How Do They Work?

Ballistic missiles are a unique type of weapon designed to deliver a warhead over long distances by following a specific trajectory, much like a thrown ball. Unlike cruise missiles, which are continuously powered and fly within the atmosphere, ballistic missiles are powered only for an initial "boost" phase.

How do They Work?

Ballistic missile flight can be broken down into three main phases:

Boost Phase

This is the first powered phase of flight. The powerful rocket engines ignite and move the missile hundreds of feet upward, and also up to hundreds of miles an hour at the same time. 

The missile achieves considerable altitude and velocity in a few minutes, as it flies above the atmosphere for relatively short-range missiles and flies into space for the longer-range missiles. 

For multi-stage missiles, this happens as the rocket burns out and is cast away. The advent of weight loss and new, Further-from-the-ground accelerations have been achieved in this phase.

Midcourse Phase

Once the boost phase ends and the engines of the rocket shut off, the missile enters free flight. The missile continues to travel upward along a predetermined trajectory known as a ballistic trajectory, which is a large curve determined only by gravity and some small aerodynamic forces (for those still within the atmosphere). 

The free flight portion of Intercontinental Ballistic Missiles (ICBMs) can last for a long time while the missile travels thousands of kilometres through space at high velocities. During the free flight period, some advanced missiles can release multiple warheads or decoys to complicate interception.

Terminal Phase

This is the final phase where the warhead (or multiple warheads) re-enters the Earth's atmosphere, descending rapidly towards its target. As it re-enters, the warhead experiences intense heat and friction due to atmospheric drag. 

The guidance system, which was initially set during the boost phase, may make final minor adjustments to ensure accuracy. This phase is very short, often lasting less than a minute, and the warhead can reach hypersonic speeds (greater than Mach 5) before impact or detonation.

Purpose of Hypersonic Missiles

The primary purpose of hypersonic missiles is to overcome existing missile defence systems and enable rapid, precision strikes against high-value targets. Their key features contribute to this purpose:

• Speed: Travelling at Mach 5 (five times the speed of sound) or greater, they significantly reduce the time available for detection, tracking, and interception.

• Manoeuvrability: Unlike traditional ballistic missiles that follow a predictable arc, hypersonic missiles can change course and altitude during flight, making their trajectory unpredictable and extremely difficult for current defence systems to counter.

• Reduced Warning Time: Their high speed means they can reach targets in minutes, leaving minimal time for defensive responses.

Advantages of Hypersonic Missiles

Hypersonic missiles offer several significant advantages:

• Evasion of Defences: Their combination of extreme speed and manoeuvrability makes them exceptionally difficult for current missile defence systems (which are primarily designed for ballistic missile trajectories) to detect, track, and intercept.

• Precision and Surprise: They can strike specific targets with pinpoint accuracy, delivering a devastating blow with little to no warning, enhancing the element of surprise in an attack.

• Global Reach and Responsive Strikes: They enable responsive long-range strikes against distant or defended targets, especially when other forces are unavailable or denied access.

• Kinetic Energy: Some hypersonic weapons rely purely on kinetic energy (energy from motion) to destroy targets, including unhardened targets or even underground facilities.

• Enhanced Deterrence: For nations with nuclear arsenals, hypersonic missiles can strengthen the credibility of their nuclear deterrent by offering a potential way to bypass existing defence mechanisms, ensuring that their nuclear weapons remain viable.

• Lower Altitude Flight: Many hypersonic missiles (especially cruise missiles) fly at lower altitudes than ballistic missiles, which can make them harder to detect at long distances with some surface-based radars.

What are the Different Types of Missiles?

Missiles are sophisticated weapons that can be categorised in several ways, depending on their characteristics and intended use. Here are some of the most common classifications:

I. By Trajectory/Flight Path:

This is a fundamental distinction that defines how a missile travels to its target.

1. Ballistic Missiles: These missiles follow a high, arcing trajectory, powered only during an initial boost phase, then coasting through space or high atmosphere before re-entering and descending to the target. They are categorised by range:

• Tactical Ballistic Missile (TBM): Range less than 300 km.

• Short-Range Ballistic Missile (SRBM): Range from 300 to 1,000 km.

• Medium-Range Ballistic Missile (MRBM): Range from 1,000 to 3,500 km.

• Intermediate-Range Ballistic Missile (IRBM): Range from 3,500 to 5,500 km.

• Intercontinental Ballistic Missile (ICBM): Range greater than 5,500 km.

2. Cruise Missiles: These missiles are continuously powered by jet engines (like a small aeroplane) and fly within the Earth's atmosphere, typically at lower altitudes, maintaining a relatively flat trajectory. They are designed for precision strikes and can often manoeuvre to avoid detection. They are often categorised by speed:

• Subsonic Cruise Missiles: Travel slower than the speed of sound (e.g., Tomahawk).

• Supersonic Cruise Missiles: Travel faster than the speed of sound (e.g., BrahMos).

• Hypersonic Cruise Missiles: Travel at speeds greater than Mach 5 (five times the speed of sound).

II. By Launch Platform and Target:

This classification defines where the missile is launched from and what kind of target it is designed to hit.

• Surface-to-Surface Missile (SSM): Launched from land or sea to hit targets on land or at sea.

• Surface-to-Air Missile (SAM): Launched from land or sea to hit airborne targets like aircraft or other missiles. Also known as air defence systems.

• Air-to-Air Missile (AAM): Launched from an aircraft to destroy other aircraft.

• Air-to-Surface Missile (ASM): Launched from an aircraft to hit targets on land or at sea.

• Anti-Ship Missile (AShM): Designed specifically to target and destroy naval vessels.

• Anti-Tank Guided Missile (ATGM): Designed to destroy armoured vehicles like tanks.

• Submarine-Launched Ballistic Missile (SLBM): Ballistic missiles launched from submerged submarines.

• Anti-Satellite (ASAT) Missile: Designed to destroy or disable satellites in orbit.

III. By Speed:

• Subsonic: Slower than the speed of sound (Mach 1).

• Supersonic: Faster than Mach 1 but slower than Mach 5.

• Hypersonic: Faster than Mach 5.

IV. By Propulsion System:

• Solid Propulsion: Uses solid propellants that are typically pre-packed.

• Liquid Propulsion: Uses liquid fuels and oxidisers that are mixed before ignition.

• Hybrid Propulsion: Combines elements of both solid and liquid propulsion.

• Ramjet/Scramjet: Air-breathing engines used for high-speed flight, especially in cruise missiles.

V. By Warhead Type:

• Conventional Warhead: Contains high explosives or other materials designed for destructive impact.

• Strategic Warhead (Nuclear-Capable): Designed to carry nuclear weapons for strategic deterrence.

• Chemical Warhead: Contains chemical agents.

• Biological Warhead: Contains biological agents.

VI. By Guidance System:

Missiles use various sophisticated guidance systems to reach their targets accurately:

• Inertial Navigation System (INS): Uses gyroscopes and accelerometers to track the missile's position and velocity from a known starting point.

• GPS/Satellite Guidance: Uses signals from satellites (like GPS or India's NavIC) for precise positioning.

• Active Radar Homing: The missile emits its radar signals to detect and track the target.

• Semi-Active Radar Homing: The missile relies on external radar (from the launching platform) to illuminate the target.

• Infrared Homing (Heat-Seeking): The missile detects and tracks the heat signature of the target.

• Laser Guidance: The target is illuminated by a laser beam, and the missile homes in on the reflected laser energy.

• Command Guidance: The missile is guided by commands sent from a ground station or launching platform.

List of Countries with Hypersonic Missiles

According to the World Population Review, here are the top countries with superpowerful hypersonic missiles in the world: