A ballistic missile is a self-guided, rocket-propelled weapon designed to deliver a payload to a predetermined target by following a parabolic trajectory. These missiles are powered by rockets for a short duration after launch, then coast toward their target under the influence of gravity. This unpowered flight constitutes the majority of their journey. The missile’s direction cannot be altered once its fuel is exhausted, as its path is determined by the initial launch speed and Earth’s gravitational pull.
The Nature of Ballistic Missiles
Ballistic missiles are categorized by their maximum range.
Short-range ballistic missiles (SRBMs) have a range of less than 1,000 kilometers (about 620 miles) and remain within the Earth’s atmosphere.
Medium-range ballistic missiles (MRBMs) travel between 1,000 and 3,500 kilometers (approximately 620 to 2,170 miles).
Intermediate-range ballistic missiles (IRBMs) cover distances from 3,500 to 5,500 kilometers (about 2,200 to 3,400 miles).
The longest-range type is the intercontinental ballistic missile (ICBM), which exceeds 5,500 kilometers (3,400 miles) and is primarily designed for delivering nuclear weapons. ICBMs travel outside the atmosphere. These missiles can be launched from various platforms, including fixed silos, mobile launchers, ships, and submarines.
Phases of a Ballistic Missile Attack
A ballistic missile’s flight consists of three phases: boost, midcourse, and terminal.
Boost Phase
The boost phase begins at launch when the missile’s engines ignite, propelling it upwards. This powered flight typically lasts between one and five minutes and occurs within the Earth’s atmosphere. During this phase, the missile accelerates rapidly, often reaching speeds exceeding 24,000 kilometers per hour for ICBMs.
Midcourse Phase
Following the boost phase, the midcourse phase commences as the rocket engines cease firing and the missile continues its unpowered flight through space. This is the longest phase, lasting up to 20 minutes for ICBMs. During this phase, the missile coasts through its highest altitude, potentially reaching about 4,500 kilometers for intercontinental missiles. During midcourse, the missile may deploy multiple warheads and decoys, making interception more complex.
Terminal Phase
The terminal phase begins when the warhead re-enters the Earth’s atmosphere. During re-entry, atmospheric drag significantly influences the missile’s trajectory. Warheads re-enter at extremely high velocities, 6 to 8 kilometers per second (about 22,000 to 29,000 km/h) for ICBMs. This phase is relatively brief, often less than a minute for ICBMs.
Ballistic Missiles Versus Cruise Missiles
Ballistic missiles and cruise missiles represent two different approaches to missile technology, distinguished by their flight paths and propulsion systems. Ballistic missiles follow a high, arcing trajectory, powered only during their initial ascent before coasting unpowered to their target. Their path is largely fixed once powered flight ends, making mid-flight course corrections limited.
In contrast, cruise missiles are continuously powered throughout their flight, typically by jet engines, much like an airplane. They maintain a relatively straight flight path within the Earth’s atmosphere, often flying at much lower altitudes, sometimes just a few meters above the ground. This low-altitude flight helps them evade detection by radar.
Cruise missiles are generally slower than ballistic missiles, traveling at subsonic or supersonic speeds, though some can reach hypersonic speeds. Their continuous propulsion allows for greater maneuverability and the ability to adjust their trajectory throughout the flight, often using advanced guidance systems like GPS or terrain-following radar. Ballistic missiles, while faster and capable of longer ranges, are typically less precise than cruise missiles, which are designed for targeted strikes.
Consequences of a Ballistic Missile Strike
A ballistic missile strike can inflict widespread destruction through several immediate physical effects.
Blast Wave
The most prominent is the blast wave, which is a powerful shockwave generated by the explosion. This blast can cause immense structural damage to buildings and infrastructure, flattening structures within the immediate vicinity of the impact. The overpressure from the blast wave can also cause internal injuries to living organisms.
Thermal Radiation
Thermal radiation, or intense heat, is another immediate consequence, particularly with nuclear warheads. This heat can cause severe burns to exposed skin and ignite widespread fires over a large area. The intensity of the thermal radiation diminishes with distance from the detonation point, but it can still cause significant damage far from the impact site.
Direct Impact Damage
Direct impact damage occurs from the kinetic energy of the missile and its warhead striking the target. This physical impact can create large craters and destroy hardened targets.
Electromagnetic Pulse (EMP)
For nuclear ballistic missiles, an electromagnetic pulse (EMP) can also be generated, particularly from high-altitude detonations. This burst of electromagnetic energy can cause severe current and voltage surges in electrical and electronic systems, potentially damaging or destroying power grids, communications networks, and unshielded electronic devices over a wide area.