Missiles and defence basics for Prelims

Classification

A missile is a guided or unguided weapon carrying a payload to a target. Ballistic missiles are powered for part of flight and then follow a largely ballistic path, often at high altitude. Cruise missiles remain powered through most of flight, fly within the atmosphere using aerodynamic lift, and can manoeuvre at low altitude. Range, speed and launch platform are separate dimensions. Hypersonic generally means Mach 5 or more, but speed alone does not tell whether a system is ballistic, cruise or boost-glide.

Missiles may be surface-to-surface, surface-to-air, air-to-air, air-to-surface, anti-ship, submarine-launched or ship-launched. Short-, medium- and long-range labels depend on the classification used. A missile’s range does not by itself reveal its payload or role.

Indian examples

Agni is a family of strategic ballistic missiles associated mainly with surface-to-surface capability. Prithvi systems are short-range ballistic systems for surface-to-surface roles. BrahMos, jointly developed by India and Russia, is a supersonic cruise missile; its name derives from the Brahmaputra and Moskva rivers. Akash is a surface-to-air air-defence system. Astra is an air-to-air missile family launched from aircraft. Anti-satellite capability targets satellites in orbit and should not be confused with ordinary air-defence interception.

Defence concepts

Air defence is a network of sensors, command-and-control and layered interceptors; one missile is not a whole network. Radar detects and tracks, while an interceptor tries to defeat the target. Deterrence seeks to prevent attack through credible capability and communication; it differs from use of force after an attack.

Prelims tips

Match BrahMos with cruise and supersonic, Akash with surface-to-air, Astra with air-to-air and Agni with ballistic surface-to-surface. Cruise missiles are not necessarily slow; ballistic missiles are not powered throughout. “Indigenously developed,” “jointly developed,” “tested” and “inducted” are different claims. Prefer stable classifications over changing variant specifications.

Prelims revision checklist

Identify the definition first, then connect it to the relevant institution, date, process and example. Do not treat a scientific mechanism as a policy instrument, an international label as automatic domestic legal status, or a rank as ownership. Watch absolute words such as “always” and “only”; they are rarely correct unless part of a formal definition. In current-affairs questions, apply the stable principle and verify changing figures or variants from an official source.

Additional recall

For elimination, ask what is being measured, who has authority, and whether the statement describes a mechanism, a legal category or an outcome. Similar terms often differ by scope and timing. A precise answer should preserve the distinction between a broad umbrella concept and its narrower operational example.

Analogy

Missiles and defence basics for Prelims — Analogy

A ballistic missile resembles a powered stone throw followed by a high arc; a cruise missile is a powered drone that keeps steering through air.