The Agni-IV is an Indian solid-fueled intermediate-range ballistic missile (IRBM) with a range of up to 4,000 km. The two-stage missile, previously named Agni-II Prime, is a derivative of the Agni-II MRBM with extended range. India has flight tested the Agni-IV eight times since its first test in 2010.

Agni-IV Development

India’s Defence Research and Development Organisation (DRDO) began developing a 5,000 km-class missile named the Agni-IV in 2007.¹ In 2011, the DRDO reapplied the Agni-IV designation to an upgraded variant of the Agni-II, the Agni-II Prime, developed by its Advanced Missile Laboratory in Hyderabad.² This missile featured an enlarged first stage motor, an upgraded second stage motor, improved guidance and electronics, and new thrust vector control systems compared to the original Agni-II.

The Agni-IV’s first flight test took place on December 10, 2010; the missile crashed into the sea shortly after launch due to errors its control system.³ The DRDO conducted the missile’s second test at its Odisha Integrated Test Range on November 15, 2011. Launched from a road-mobile launch truck, the Agni-IV travelled 3,000 km and reached a maximum altitude of 900 km before landing in the Bay of Bengal.⁴

On September 19, 2012, the DRDO successfully test launched the Agni-IV to a range of 4,000 km. The test missile reportedly carried a live conventional payload, which landed near its target with an accuracy of under 100 meters.⁵

On January 20, 2014, the DRDO successfully flight tested the Agni-IV to a range of 4,000 km. Launched from a road-mobile launcher, the missile reached a maximum altitude of 850 km before landing in the Indian Ocean. The missile reportedly carried a mock nuclear warhead (“the entire warhead minus the nuclear part”), detonating its conventional explosive lenses near its target. ⁶

On December 2, 2014, the Indian Army Strategic Forces Command (SFC) conducted its first user trial of the Agni-IV, successfully launching it to a range of “over more than 3,500 km.” The trial was the first of three to four tests typically conducted before induction into service.⁷ SFC conducted three additional successful tests on November 9, 2015, January 2, 2017, and December 3, 2018.⁸

Agni-IV Design

The Agni-IV is two-stage, solid-fueled missile weighing 17,000 kg. The missile is approximately 20 meters long and 1.2 meters in diameter at its lower stage. It is designed to carry a 1,000 kg payload to ranges up to 4,000 km, but in 2017 Indian Army sources suggested it would test the missile to ranges under 3,500 km to meet user requirements. ⁹ The Indian Ministry of Defence has, on various occasions, claimed the missile’s range as 3,000 km, 3,500 km, and 4,000 km.¹⁰

The Agni-IV uses a 1.2 meter-diameter, maraging steel-cased first stage and a roughly 1 meter-diameter carbon-fiber-cased second stage to generate 710 and 39.5 kN of average thrust respectively. It employs an inertial guidance system with ring laser gyroscopes and flexseal thrust vectoring systems to control its orientation in flight.¹¹ According to India’s defense ministry, the missile is accurate to less than 100 meters circular error probable (CEP) at a range of 4,000 km.¹² It is capable of loading nuclear and conventional payloads, and was reportedly tested with unitary conventional and partly assembled nuclear payloads in tests. Its nuclear payload is estimated to weigh 1,000 kg.