Agni-III

Agni-III is an intermediate-range ballistic missile developed by India as the successor to Agni-II. It has a range of 3,500 km- 5,000 km, and is capable of engaging targets deep inside neighbouring countries. The missile’s Circular error probable (CEP) is within 40 meters range, which makes it the most sophisticated and accurate ballistic missile of its range class in the world. In June 2011, it was reported that Agni-III has been inducted into the armed forces and is under-production.

Introduction
India's Minimum Credible Nuclear Deterrence envisages a triad of nuclear counterstrike capability which required a long range missile to provide robust second strike capability. A missile system that can be dispersed far and wide in the Indian mainland, its far flung islands or its blue water naval assets dispersed across the world's oceans. Following this necessity India developed a larger Agni-III missile, with a heavier payload and a longer range but in a compact configuration, i.e. thicker but shorter length. This development is driven by need for a more assured retaliation that can defeat emerging ABM defences and countermeasures. Such capability requires a compact missile that can also carry ABM counter-measure payloads along with weapons, in a configuration similar to MIRV, albeit with state-of-the-art decoys.

Description
Agni III—an intermediate-range ballistic missile—was developed by India as the successor to Agni-II. Designed by the Indian government's Defence Research and Development Organisation, Agni III is a two-stage ballistic missile that is capable of nuclear weapons delivery. It was designed and developed by the Advanced Systems Laboratory (ASL), a unit of DRDO, which was formed in September 2001 with its main objective being the development of large-sized rocket motors. ASL developed the propulsion plant for solid-fuel motors, including the infrastructure for propellant casting.

The Agni-III has two stages with an overall diameter of 2.0 m. The first stage mass is about 32 tonnes and 7.7 m long, the second stage mass is about 10 tonnes and 3.3 m long. The missile is likely to support a wide range of warhead configurations, with a 4,500 km range and a total payload weight of 2490 kg.

The stubby two-stage solid fuel missile is compact and small enough for easy mobility and flexible deployment on various surface/sub-surface platforms.

The missile is equipped with sophisticated navigation, guidance and control systems along with advanced on-board computer systems. The electronic systems are hardened for higher vibration, thermal and acoustic effects. A high performance indigenous ring laser gyro-based navigation system was flight-tested for the first time during the Agni-III trial on 7 Feb 2010.

Propulsion
The Agni-III features two solid fuelled stages and with overall diameter of 2.0 meters. This diameter is compatible with a recently tested Indian sub-surface launch system, which has a 2.3 meter diameter launch tube aperture.

First stage booster
The first stage booster is made of advanced carbon composite materials to provide high payload fraction (mass fraction). It weighs about 32 tonnes, is 7.7 meters long and diameter of 2 metres.

Second stage
The second stage made of maraging steel weighing about 11 tonnes and a length of 3.3 metres. The second stage has flex nozzles, to provide necessary flight trajectory control.

Maneuvering re-entry vehicle: Agni RV-Mk.4
Agni-III supports a wide range of weapons, with total payload weight ranging from ~600 kg to 1,800 kg including decoys and other ABM countermeasures. Instead of conventional bus architecture, the RV (Re-Entry Vehicle) is self-contained with velocity correction package, navigation and re-entry control systems.

The lighter and tougher RV body has an all-carbon composite re-entry heat shield with multi-directional carbon re-entry nose tip and control surfaces. The new lightweight composites can withstand temperatures of up to 6000 degrees Celsius, and are capable of greater re-entry velocity.

K-4 SLBM
The K-4 missile is one of the series of missile developed under the K-X series. DRDO is working on a submarine-launched version of the Agni-III missile, which will provide India with a credible sea-based second-strike capability. The K-4 missile, with a range of 3500 km, is expected to be test fired for the second time in January 2011. An as-yet unnamed variant of K-4 with 5000 km range is under development.

Flight tests
The first test for Agni III was conducted from Wheeler Island off the Bhadrak coast on 9 July 2006. The launch proved to be unsuccessful, with the missile falling into the sea off the coast of Odisha, short of reaching the target. According to DRDO, the failure was due to a first stage anomaly that was caused by recirculating hot gases entering the missile-base shroud and damaging the electronic components. Indian Defence Minister Pranab Mukherjee reported it as "partial success" (a trade euphemism to indicate the test generated useful data for diagnosis and correction) as the missile was air-borne for only 5 minutes instead of the expected 15 minutes.

Agni-III was test fired again on 12 April 2007, from the Wheeler Island off the coast of Odisha. This time, the launch was declared as a success. India's Cabinet Committee on Security announced that "This test confirms the extent of India's nuclear reach and India's nuclear deterrence as the missile can accurately hit targets at distance more than 3000 km away". Already the most powerful and capable in India's missile inventory, the Agni-III is capable of carrying a variety of warheads, including nuclear warheads and can be launched from various platforms giving India intermediate range ballistic missile firepower and greatly extending India's power projection in the region.

Agni III was test fired successfully for third time on 7 May 2008. The missile was launched from Balasore, Odisha. After a flight of roughly 15 minutes defence scientists confirmed that the test fire was successful and that the missile met all parameters. The missile has a velocity of 5,000 meters per second. Agni-III is a nuclear capable fully solid propellant fuelled surface-to-surface missile, and has a range of 3,500 km. A new software for navigation system fitted on the missile will increase accuracy and lethality. The successful test on 7 May opened the doors for the next generation Indian ICBM Agni V with a range of 5,000–6,000 kilometres.

The development test of Agni III was put off for unknown reasons in August 2009.

Agni III was tested successfully for the fourth time from Wheeler Island in Odisha on 7 February 2010. The missile is said to have hit the target with pin point accuracy and met all the mission objectives. Two down range ships located near the target tracked and witnessed the Missile reaching the target accurately. The missile is likely to support a wide range of warhead configurations, with a 3,500 km range and a total payload weight of 2490 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 test validated the nuclear triggering mechanism, meaning Agni-III is meant for strategic nuclear deterrence. The test launch is part of pre-induction of the missile into the Indian Army.

In August 2010, the defence minister of India announced that Agni-III is ready for induction and in June 2011, it was reported that the Agni-III missile had already been inducted into the armed forces.

In September 2012, it is reported that a missile group is now being raised with Agni-III missiles.

On 21 September 2012, as part of regular user-training the Strategic Forces Command test fired an Agni III missile from a rail mobile launcher. The missile was randomly chosen from a production lot. All mission objectives were achieved and the missile hit the pre-designated target with a two-digit accuracy.