India has several systems in place to defend against incoming aerial attacks. Stopping an incoming missile or an aircraft flying at high speeds is tricky so a country cannot just rely on one particular system for it. One of the notable systems that India has to thwart incoming aerial targets like fighter jets, cruise missiles and air-to-surface missiles is Akash mid-range surface-to-air missile (SAM) system built by Defence Research and Development Organisation (DRDO). It is medium range nuclear capable supersonic missile. The missile system can target aircraft up to 30 km away, at altitudes up to 18,000 mts. It is in operational service with the Indian Army and the Indian Air Force. Another system that India has been working on is Ballistic Missile Defence (BMD) program. A Ballistic Missile Defence (BMD) is a system that is designed to intercept and destroy an incoming ballistic missile on its trajectory much before it approaches the target. India’s ballistic missile defence system provides a two-layered shield – ‘exo’ and ‘endo’. What this effectively means is that the system provides protection both against ballistic missiles that are outside (exo) as well as inside (endo) the earth’s atmosphere. Prithvi Air Defence (PAD) is supposed to tackle incoming missiles at ranges of 80-120 km (exo-atmospheric interception). On the other hand, the advanced air-defence (AAD) mainly consists of Akash Surface-to-Air Missiles (SAM) that can intercept incoming missiles at ranges of 15-30 km (endo-atmospheric interception). To add to its arsenal, India is set to purchase S-400 Triumf air defence missile systems from Russia. S-400 Triumf is one of the world’s most advanced air defence systems that can simultaneously track numerous incoming objects – all kinds of aircraft, missiles and UAVs – in a radius of a few hundred kilometres and launch appropriate missiles to neutralise them. The S-400 Triumph air defence system integrates a multifunction radar, autonomous detection and targeting systems, anti-aircraft missile systems, launchers, and command and control centre. The two other major air defence systems with India are Spyder and Barak 8. While Spyder has a range of just 15 kilometres, Barak 8, a joint project of the DRDO and the IAI, has a longer range of at least 70 kilometres. All these systems are optimised for different roles and have different capabilities. Like, PAD and AAD are primarily to stop ballistic missiles which sear towards targets at supersonic speeds. S-400 is optimal for stopping cruise missiles, UAVs and fighter aircrafts. Even Aakash is capable of neutralising aerial targets like cruise missiles, fighter jets, unmanned aerial vehicles (UAV) and air-to-surface missiles. Even the ranges are different. Prithvi Air Defence (PAD) is supposed to tackle incoming missiles at ranges of 80-120 km (exo-atmospheric interception). Aakash can engage targets in the range of around 30 kms. S-400 Triumf air defence missile system is a far more complex and advanced system. The highly automated S-400 has radars that can pick up an incoming object up to a 1,000 kilometres away, track several dozen incoming objects simultaneously, distribute the targets to appropriate missile systems and ensure a high success rate. The S-400 Triumph also launches 9M96E and 9M96E2 medium range ground-to-air missiles. Designed for direct impact, the missiles can strike fast moving targets such as fighter aircraft with a high hit probability.