Explained: What is Agni Prime, the new-generation ballistic missile test-fired by India

The Indian Defence Ministry announced the successful test firing of the country's New Generation Ballistic Missile Agni-Prime, from the Dr APJ Abdul Kalam Island, off the Odisha coast. This test was carried out at 7 pm Indian Standard Time on Wednesday (Apr 3).

This launch was executed by the Defence Research and Development Organization and the Strategic Forces Command (SFC), which comprises personnel from the Indian Army, Navy and Air Force.

The SFC is incharge of handling the country's nuclear arsenal, while the DRDO is responsible for developing weapons systems and related military technologies. 

"The test met all the trial objectives validating its reliable performance, as confirmed by the data captured by a number of range sensors deployed at different locations, including two downrange ships placed at the terminal point", said the Defence Ministry statement.

Also Read | Congress MP Randeep Singh Surjewala and BJP MP Hema Malini row: Here's what happened

It added that the test firing was witnessed by the Chief of Defence Staff, Chief of Strategic Forces Command and Senior officials from the DRDO and Indian Army. 

Salient features of Agni-Prime

The solid-fuelled Agni-Prime is a surface-to-surface missile capable of hitting targets at ranges of 1200-2000 kilometres. Having such a range puts it in the class of medium-range ballistic missiles. For context, the Intercontinental ballistic missiles are those that have ranges exceeding 5,500kms.

In a vast majority of missiles, it is common to use solid fuels (which are pre-filled), as opposed to liquid fuels, which are filled into the missile just a few hours before firing (similar to how fuel is filled in planes and conventional vehicles), which makes the logistics and handling process very challenging.

Also Read | Lok Sabha elections 2024: 22 leaders quit Chirag Paswan's party, say tickets were given to outsiders

Liquid fuels used in missiles are not always easy to store and handle and some fuels are toxic in nature and sensitive to other ambient factors.

Solid fuels are most widely used in missiles, as it helps store them for a long time. During the manufacturing process of solid-fuel missiles, the fuel and oxidizer in a fine powder form are bound together by a rubbery material and packed into a metal casing. For example, a solid-fuel missile can be stored for many years together, with just minimum inspection at periodic intervals. 

Another feature of the Agni-Prime is the use of composite materials in the build of the missile. The material is produced by merging two or more materials with different properties, to eventually create a material with certain specific, unique properties.

Watch | India braces for extreme heatwaves; should poll campaigns reflect climate issues?

In the case of rockets and missiles, the composites used must be able to withstand the stresses and loads of high-speed flight, withstanding the high temperatures. Composites are used because they are often lighter and much stronger than some metal alloys. Having lesser overall weight also enhances the payload capacity and range of the missile.

Agni-Prime is a canisterised missile, which means that it is stored in a launch tube or canister, unlike other missiles that are exposed to the outside environment. A canisterised missile would have its warhead preloaded before it is placed in the launch tube. This offers the ability to launch with minimal preparation time. 

Storing a missile in a canister or launch tube protects it from the elements- dust, debris, and also possible damage during any mode of transport and handling. It also requires less maintenance. They can also be easily integrated into various platforms for launch- from land, air or sea.

The Prime variant of the Agni missile also benefits from a host of advanced sensors, navigation and guidance systems which significantly enhance the precision of the missile and its impact. It is also the smallest and lightest variant in the Agni series of Indian ballistic missiles. It is meant to replace the initial stages 

What is a Ballistic Missile and why is it named so? 

A Ballistic missile follows a ballistic flight path - which comprises three phases of flight. In the first phase or the boost phase, the solid-fuel rocket engine propels the missile upwards and it has to rapidly gain velocity and altitude, by knifing through the densest parts of the earth's atmosphere. 

The second and unpowered phase of flight happens in the upper reaches of the earth's atmosphere or in space, where the missile travels along its pre-determined path, but without the power of its engines.

It is known as the coast phase or mid-course phase and during this time, it travels along a horizontal path. During the coasting, the missile is either in space or the upper atmosphere, where it faces minimal resistance or drag. 

In the third and final phase or the terminal phase, the missile descends and gets back into the earth's atmosphere and flies towards its target, while being guided by its on-board systems. 

Past tests of Agni-Prime

On June 7, 2023, India's SFC performed the first pre-induction night launch of the Agni-Prime and successfully accomplished the mission objectives.

This test was conducted after three successful developmental trials of the missile, validating the accuracy and reliability of the system.

The latest test is the second pre-induction night launch of the Agni-Prime. Generally, a couple of tests are conducted in various phases, before inducting the missile into the arsenal. Each of these tests helps validate different technical parameters and offers insights into the consistent performance of the missile.