by G Hari Kumar

Use of modern weapon systems has revolutionised the concept of warfare. Technology as a force multiplier, provides the competitive and cutting edge. The technology of guided missiles encompasses the multiple streams of engineering, technology and applied sciences. A number of factors are responsible for the successful launch of missiles. These involve coordination of a variety of subsystems.

WHAT IS A MISSILE?

Basically any object thrown at a target with the aim of hitting it is a missile. The incorporation of energy source in a missile to provide the required force for its movement (propulsion), intelligence to go in the correct direction (guidance) and effective manoeuvring (control) are mainly the technologies of guided missiles. They help in making a missile specific to a target, that is, they determine the size, range and state of motion of a missile.

INTRODUCTION

South Asia's feeble political and strategic equations are reflected in the volatility of its security arrangements. The evolution of elements that have been crucial towards galvanizing India's strategic response crucially include its missile programme as an unassailable part of that strategy.

What is an ICBM?

 It is a guided ballistic missile - which follows a path - and has a range of 5,500 km. ICBM's have a greater range and speed than other ballistic missiles.They are primarily designed for nuclear weapons delivery but can also carry chemical and biological weapons. As of 2018 all five of the nations with permanent seats on the UNSC - The US, Russia, China, Great Britain and France - have operational long-range ballistic missile systems. India though is a new and addtional entrant into this exclusive club.

 The Speed Factor

 An ICBM constantly changes speed and altitude. But the peak speed is about 6-7 km/s. New Delhi to Beijing is 3,800 km and at 6.5km/s would take about 9.75 minutes for a missile to reach there.

The past decades have witnessed phenomenal surges in missile technology and intrusions into outer space. India, however did not have a credible missile program by means of which it could boast of a sturdy arsenal of missile systems of that point. India's missile program can be stated to be an offshoot of its space program, beginning 1967. Subsequently, in 1972, Rohini- a 560 two-stage, solid propulsion sounding rocket was developed and test fired, capable of reaching an altitude of 334 km with a 100 kg payload. India first launched its small 17-tonne SLV-3 space booster (300 km/40 kg) in 1979 and thereafter successfully injected the 35 kg Rohini I satellite into near-earth orbit in 1980. By 1987, an augmented booster, the 35-tonne ASLV (4,000 Km /150 kg in low earth orbit), which primarily are three SLV-3's strapped together, had begun flight testing.

In what could be described as a 'decisive shift' in missile development plans, the missile capability of Indian armed forces received a major fillip from Defence Research and Development Organisation (DRDO) following the launching of the Integrated Guided Missile Development Program (IGMDP) in 1983. The principal aim was to develop a family of strategic and tactical guided missiles based on local design and development for three defence services. DRDO accorded particular priority to development of sophisticated guidance technology.

AGNI Series of Ballistic Missiles

The Agni missile ("Fire" in Sanskrit) is a family of medium to intercontinental range ballistic missiles developed by India, named after one of the five elements of nature. Agni Missiles are long range, nuclear weapons capable surface to surface ballistic missile.

The five Agni variants, all ballistic missiles, form the bulwark of India’s nuclear deterrence. The single-stage, 15-metre-long, 12-tonne Agni-I, with a range of 750 km, was developed in 15 months after the Kargil war ended in June 1999. The two-stage Agni-II (20 m, 17 tonnes) followed. Agni-III’s weight of 50 tonnes was a quantum jump. Agni-IV used several new technologies, including rocket motors made of composites, to bring the weight down to just 17 tonnes to have modern avionics in order to accommodate navigation and guidance systems. With the addition of an extra (third) stage, the Agni-III metamorphosed into the redoubtable Agni-V.

Agni-I is a single stage, solid fuel, road and rail mobile, medium-range ballistic missiles (MRBM) using solid propulsion upper stage, derived from Prithvi, essentially to prove the re-entry structure, control and guidance. The strap-down inertial navigation system adopts explicit guidance—attempted for the first time globally. Using carbon composite structure for protecting payload during its re-entry phase, the two-stage Agni technology demonstrator, with a solid-fuel first stage, was first tested at the Interim Test Range in Chandipur in 1989, thus establishing the re-entry technology and precise guidance to reach the specific targets. This shorter ranger missile is specially designed to strike targets in Pakistan.

Agni-II is an operational version of Agni I and is an intermediate range ballistic missile (IRBM) with two solid fuel stages and a Post Boost Vehicle (PBV) integrated into the missile’s Reentry Vehicle (RV) with mobile launch capability test-fired in April 1999. The range for Agni II is more than 2,000 km. Quick deployment of the Agni II was possible, by building on the earlier Agni-TD program that provided proven critical technologies and designs required for long range ballistic missiles. The Agni II missile was last test fired in May 2009.

Agni-III is an intermediate-range ballistic missile and the successor to Agni II. Intended to be a two-stage ballistic missile capable of nuclear weapons delivery, it is touted as India’s nuclear deterrent against China. The missile is likely to support a wide range of warhead configurations, with a 3,500 km range and a total payload weight of 2,490 kg. The two-stage solid fuel missile is compact and small enough for easy mobility and flexible deployment on various surface/sub-surface platforms. The last development test of Agni III was conducted in August 2009 before being handed over to the army for user trails and operational use.

Agni-IV is a two-stage nuclear-capable intermediate range ballistic missile. The missile was first tested in November 2011 from Wheeler Island. It rose to an altitude of 900 km during the test. It was successfully test-fired again in September 2012. It reached an altitude of 850 km during its third test in January 2014. The missile was also successfully test-fired in January 2017.

The Agni-IV has a length of 20 m and weight of 17t. It can carry a payload of 800 kg. The maximum range of the missile is 4,000 km.

Agni-V an upgraded version of the Agni III is currently being worked upon by the DRDO. The intercontinental ballistic missile or ICBM shall have a range of about 5000-8000 km. Agni V is a three stage solid fueled missile with composite motor casing in the third stage. Agni V will be able to carry multiple warheads and would also display countermeasures against anti ballistic missile systems. The Agni-5 is specially tailored for road-mobility. With the canister having been successfully developed, all India's future land-based strategic missiles will be canisterised as well. Made of maraging steel, a canister must provide a hermetically sealed atmosphere that preserves the missile for years. During firing, the canister must absorb enormous stresses when a thrust of 300 to 400 tonnes (300 to 390 long tons; 330 to 440 short tons) is generated to eject the 50 tonnes (49 long tons; 55 short tons) missile. If the missile is ejected using a gas generator from the canister, then the missile could be launched from any pre-surveyed launch location without the need for any pre-built launch site.

On 18 January 2018, a fifth test of the missile was successfully conducted. This was the third consecutive canisterised test of the missile on a road mobile launcher and the "first pre-induction trial" or in the final operational configuration. The missile covered a distance of 4,900 km in 19 minutes.

India’s long range missiles such as Agni IV and Agni V are the core of its deterrence against China.

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