Over the last few months the Agni series has been in the news after repeated successful firings, but the story of Agni — and of Akash and Prithvi — actually began in 1983. These weapons trace their origins to the Integrated Guided Missile Development Programme (IGMDP), conceived by then prime minister Indira Gandhi, defence minister R. Venkataraman and DRDO chief V.S. Arunachalam.The aim was to build domestic capability in critical missile technologies and achieve autonomy in strategic weapons. Dr A.P.J. Abdul Kalam, known as the father of India’s missile programme, was moved from ISRO’s SLV-3 project to lead the effort.
IGMDP focused on five distinct missile projects, each designed for a specific operational role: Agni, Prithvi, Akash, Trishul and Nag.The missiles were intended to provide roles ranging from strategic deterrence to shooting down aircraft and missiles, and giving soldiers the ability to engage enemy tanks.
Prithvi
Prithvi was India’s maiden short-range ballistic missile. With a range of 150–300 kilometres and a payload capacity of up to 1,000 kilograms, Prithvi was intended for battlefield use and could carry nuclear warheads. Variants were developed for the army, navy and air force, with the naval version (Dhanush) tested in 2004. Prithvi’s induction in the 1990s marked India’s entry into the ballistic-missile club.
Agni
The Agni series began as a technology demonstrator and has evolved into India’s primary strategic deterrent. The family now includes missiles with ranges from about 700 km to over 5,000 km. The programme introduced advanced re-entry technologies to protect warheads returning from space at very high speeds. Agni has grown from Agni-I through Agni-V, with Agni-Prime and Agni-VI under development to extend range and capability further.
Akash
Akash also evolved from the IGMDP. This medium-range surface-to-air missile has been credited with strong performance in operations such as Operation Sindoor, where it engaged Pakistani drones and missiles. Akash has a range of about 25 km and can engage targets at altitudes up to roughly 18 km (around 60,000 feet). It has been deployed by both the army and the air force. A phased-array radar developed alongside Akash can track over 40 targets. Newer variants — Akash-1S, Akash Prime and Akash NG — are replacing Soviet-era systems in service.
Trishul
Trishul was envisioned as a short-range surface-to-air missile for point defence against low-level sea-skimming threats such as anti-ship missiles and low-flying aircraft. Projected with a range of about 12 km, it was ultimately shelved in 2008. Although not inducted, Trishul served as a technology demonstrator and advanced DRDO’s knowledge of guidance and control. The Very Short Range Air Defence System (VSHORADS) now performs similar roles.
Nag
The Nag is a third-generation anti-tank guided missile, the final element of IGMDP. With a range of up to 4 km, Nag uses an infrared imaging seeker to locate modern main battle tanks and defeat them with a tandem high-explosive anti-tank warhead designed to defeat explosive reactive and composite armour. It was integrated with the NAMICA (Nag Missile Carrier) and adapted for helicopter launch in the Helina and Dhruvastra variants. The Nag family will equip platforms such as the Prachand and Rudra helicopters, NAMIS tank hunters and Zorawar tanks. Development also produced a man-portable ATGM.
Challenges and legacy
IGMDP faced significant challenges from international technology denial regimes such as the Missile Technology Control Regime (MTCR). Missile tests in the late 1980s triggered restrictions on transfers of critical components, forcing India to develop indigenous substitutes. While this slowed progress, it also helped establish a robust defence ecosystem.The programme transformed India into a credible missile developer. Lessons from the five projects enabled newer systems such as the Astra series and strengthened capabilities across tactical strikes and strategic deterrence. By the time the programme was formally declared complete in January 2008, India had achieved substantial technological independence in missile development. Not all projects met every initial goal, but overall the achievements were monumental: Agni became the backbone of strategic autonomy, Akash proved effective in combat, Nag matured into a credible anti-tank system, and even Trishul contributed valuable lessons. IGMDP stands as a landmark that marked the transition from dependence to self-reliance.